Critique of ‘A path to sustainable energy by 2030′

The November 2009 issue of Scientific American has a cover story by Mark Z. Jacobson (Professor, Stanford) and Mark A. Delucchi (researcher, UC Davis). It’s entitled “A path to sustainable energy by 2030” (p 58 – 65; they call it WWS: wind, water or sunlight). This popular article is supported by a technical analysis, which the authors will apparently submit to the peer-reviewed journal Energy Policy at some point (or may have already done so). Anyway, they have made both papers available for free public download here.

So what do they say? In a nutshell, their argument is that, by the year 2030:

Wind, water and solar technologies can provide 100 percent of the world’s energy, eliminating all fossil fuels.

Big claim. Does it stack up? Short answer, no. Here I critique the 100% WWS plan (both articles).

The articles are structured around 7 parts: (1) A discussion of ‘clean energy’ technologies and some description of different plans for large-scale carbon mitigation. (2)  The amount and geographic distribution of available resources [wind, solar, wave, geothermal, hydro etc.] are evaluated, globally. (3) The number of power plants or capture devices required to harness this energy is calculated. (4) A limit analysis is undertaken, to determine whether any technologies are likely to face material resource bottlenecks that risk stymieing their large-scale deployment. (5) The question of ‘reliability’ of energy generation is discussed. (6) The projected economics of this vision are forecast. (7) The policy approaches required to turn vision into reality are reviewed.

In this post I want to concentrate on (5) and (6) — what I consider to be “The Bad”. But first, let’s look quickly at “The Good” (actually, more like the “Okay”) and then the really “Ugly” parts.

The majority content of the twin papers is focused on making the banal point that there is a huge amount of energy embodied in ‘wind, water and sunlight’ (“Plenty of Supply”), and that a wide diversity of technologies have been developed to try and harness this into useable electrical power.  No critic of large-scale renewable energy would argue any differently, and the size of these resources has been covered in detail by David Mackay. In that context, I wonder what they hope to add to the literature? There’s nothing wrong in this section, and well explained, but it’s just standard, rehashed fare.

Next comes a simple extrapolation of the total number of wind turbines, solar thermal facilities, etc. required to deliver 11.5 TWe of average power (close to my figure of 10 TWe in TCASE 3). This part is similar to that which I provided in TCASE 4 except they use a mix of contributing technologies rather than considering a hypothetical limit analysis for each technology individually. Curiously though, they never really explain (in either paper) how they came up with their scenario’s relative mix of hydro capacity, millions of wind turbines, billions of solar PV units, and thousands of large CSP plants, wave converters, and so on — except in pointing out that some resources are more abundant in deployable locations than others (see Table 2 of the tech paper). They do provide a useful discussion of possible material component bottlenecks for different techs (e.g. Nd for permanent magnets in wind turbines, Pt for hydrogen fuel cells, In/Ga etc. for solar PV), and argue how they can be plausibly overcome via recycling and substitution with cheaper/more abundant alternatives. This bit is quite good.

So what’s “The Ugly”? Well, it’s something utterly egregious and deceptive. In the Sci Amer article, the following objection is raised in order to dismiss the fission of uranium or thorium as clean energy:

Nuclear power results in up to 25 times more carbon emissions than wind energy, when reactor construction and uranium refining and transport are considered.

Hold on. How could this be? I’ve shown here that the “reactor construction” argument is utterly fallacious – wind has a building material footprint over 10 times larger than that of nuclear, on energy parity basis. Further, Peter Lang has shown that wind, once operating, offsets 20 times LESS carbon per unit energy than nuclear power, when a standard natural gas backup for wind is properly considered. I’ve also explained in this post that the emissions stemming from mining, milling, transport and refining of nuclear fuel is vastly overblown, and is of course irrelevant for fast spectrum and molten salt thorium reactors. So…?

Well, you have to look to the technical version of the paper to trace the source of the claim. It comes from Jacobson 2009, where he posited that  nuclear power means nuclear proliferation, nuclear proliferation leads to nuclear weapons, and this chain of events lead to nuclear war, so they calculate (?!) the carbon footprint of a nuclear war! (integrating a probability of 0 — 1 over a 30 year period). I quote:

4d. Effects of nuclear energy on nuclear war and terrorism damage

Because the production of nuclear weapons material is occurring only in countries that have developed civilian nuclear energy programs, the risk of a limited nuclear exchange between countries or the detonation of a nuclear device by terrorists has increased due to the dissemination of nuclear energy facilities worldwide. As such, it is a valid exercise to estimate the potential number of immediate deaths and carbon emissions due to the burning of buildings and infrastructure associated with the proliferation of nuclear energy facilities and the resulting proliferation of nuclear weapons. The number of deaths and carbon emissions, though, must be multiplied by a probability range of an exchange or explosion occurring to estimate the overall risk of nuclear energy proliferation. Although concern at the time of an explosion will be the deaths and not carbon emissions, policy makers today must weigh all the potential future risks of mortality and carbon emissions when comparing energy sources.

Really, need I say more? Can it really be that such wildly conjectural nonsense is acceptable as a valid scientific argument in the sustainable energy peer-reviewed literature? It seems so, which suggests to me that this academic discipline needs a swift logical kick up its intellectual rear end.

So, on to the grand renewables plan. The fulcrum upon which the whole WWS analysis pivots is the section entitled “Reliability”.  Here’s where the steam and mirrors of their WWS dream (sorry, solar thermal pun) really starts to blow off into the atmosphere and shatter on the ground.

First, the authors cite ‘downtime’ figures for each technology (i.e., the period of unscheduled maintenance, as opposed to scheduled outages). From this, they leave the uninitiated reader with the distinct impression (especially in the Sci Amer pap piece) that wind and solar PV is actually more ‘reliable’ than coal! (Who knew? We’d better tell the utilities). They also say that unscheduled downtimes for distributed WWS technologies will have less impact on grid stability than when a large centralised power plant suddenly drops out. Sorry, but I just don’t get this. If the downtime of solar PV is 2%, for instance, and you have 1.7 billion 3 kW units installed worldwide (their calculated figure), then 340,000 of them are out at any one time. That seems rather significant to me…

Next, to overcome intermittency, they claim that for an array of 13-19 wind farms, spread out over an 850 x 850 km region and hypothetically interconnected:

… about 33% of yearly-averaged wind power was calculated to be useable at the same reliability as a coal-fired power plant.

Let’s parse this. By reliability of the coal plant, I assume in this context that they mean its capacity factor (rather than unscheduled outages), which would be around 85% of peak output. Now, wind in excellent sites has a capacity factor of ~35%, so the yearly-averaged power of a hypothetical 10 GW peak wind array of 13-19 farms would be 3.5 GW. Now, following their statement, 33% of 3.5 GW — that is, 1.15 GW or ~12% of peak capacity — would be available 85% of the time. Or, to put it another way, we’d need to install 10 GW of peak wind to replace the output of 1.4 GW of coal? Is that what they are saying? Did they cost this? (hint: no, see below). Perhaps someone else can confirm or reject my interpretation of the statements on p19 of the tech paper.

Also, consider this. Say we instead installed 20 GW peak over this 850 x 850 km area. We’d still only be able to deliver 20 x 0.35 x 0.33 = 2.3 GW of baseload-equivalent power. That is, adding more and more wind doesn’t help with system reliability, as it would for coal.  I suppose the overall system reliability might get a little better as you spread your wind farm array over increasingly large geographical areas, but I suspect that this would be a case of rapidly diminishing returns. How can such a scheme be considered economic?

(Note: I’m not arguing for coal here, just using the power technologies given in their example. For me, insert nuclear instead).

Then they introduce ‘load-matching’ renewables. For instance, they present a “Clean Electricity 24/7” figure for California (see above), in which geothermal, wind, solar and hydro together provide a perfect match to an average power demand curve for CA for a given month (July in this figure). Strangely though, they neglect to mention what happens during the many imperfect, less-than-average days, when it’s cloudy and/or calm for some or most of the day and night (or strings of days/nights), or how much extra capacity is needed in winter months. How is the gap filled if either or both of wind/solar is mostly unavailable? Do the residents of CA go without electricity on those days? Err, no. Apparently, in these instances, grid operators must ‘plan ahead for a backup energy supply’. Riiiight. Where does this come from again, and how will this be costed into the WWS economic equation?

I could go on here, but won’t. This post is already getting way too long, and besides, many of these points will be topics, in and of themselves, in future TCASE posts.

As you’d have already gathered from the above, the economics of WWS is pretty strange. Here’s another example:

Power from wind turbines, for example, already costs about the same or less than it does from a new coal or natural gas plant, and in the future is expected to be the least costly of all options.

How can they justifiably say this, and yet neglect to mention that the power these these technologies produce is variable in quanity, low quality (in terms of frequency control), not dispatchable, diffuse (thereby requiring substantial interconnection), and that their projected energy prices don’t include costs of backup? In other words, in the real world, what exactly does the above quoted statement mean? Nothing meaningful that I can see.

They make a token attempt to price in storage (e.g., compressed air for solar PV, hot salts for CSP). But tellingly, they never say HOW MUCH storage they are costing in this analysis (see table 6 of tech paper), nor how much extra peak generating capacity these energy stores will require in order to be recharged, especially on low yield days (cloudy, calm, etc). Yet, this is an absolutely critical consideration for large-scale intermittent technologies, as Peter Lang has clearly demonstrated here. Without factoring in these sort of fundamental ‘details’ — and in the absence of crunching any actual numbers in regards to the total amount of storage/backup/overbuild  required to make WWS 24/365 — the whole economic and logistical foundation of the grand WWS scheme crumbles to dust. It sum, the WWS 100% renewables by 2030 vision is nothing more than an illusory fantasy. It is not a feasible, real-world energy plan.

I also see that they are happy to speculate about dramatic future price drops for solar PV and concentrating solar thermal with up to 24 hours future storage (Although even they admit it would not provide sufficient power in winter – what do we do then, I wonder? – have huge capacities of coal and gas on idle and as spinning reserve?). Well, I guess that if analysts like Jacobson and Delucchi are willing to forecast such optimistically low costs for future solar, then we can be quite comfortable doing the same for IFR and LFTR, the Gen IV nuclear. What’s good for the goose…

Finally, a quick note on the section “Policy Approaches”. I found one thing particularly amusing. They start by emphasising the critical need for feed-in tariffs (FITs), to subsidise the initial deployment of WWS technologies, because these deliver a necessary kick start towards lower future costs. It’s ironic then, that they end with a quote from Benjamin Sovacool (2009) which says:

Consumers practically ignore renewable power systems because they are not given accurate price signals about electricity consumption. Intentional market distortions (such as subsidies), and unintentional mark distortions (such as split incentives) prevent consumers from becoming fully invested in their electricity choices.

Well, excuse me, but if FITs, and WWS technologies that are priced without adequate storage/backup, are not market distortions and subsidies, then what the hell is?

—————————————-

Charles Barton at Nuclear Green has two further useful critiques of the WWS papers here and here; these follow on from his earlier dissections of Jacobson, Archer’s and Sovacool’s work.

—————————————-

Appendix: Further comments on WWS from Dr. Gene Preston of SCGI:

By profession I do transmission studies for wind and solar clients. My company name is TAC meaning Transmission Adequacy Consulting. I currently am doing studies all across the US.  “A path to sustainable energy by 2030″ omits the transmission system needed by 2030.  Because the wind and solar and water and geothermal projects are not in the locations of the existing power plants, new lines will be needed.

Looking at the graph on page 63, and carefully measuring scales on the graph, I estimate that there is 40,000 MW of wind and 40,000 MW of centralized solar on that graph. The reason I omitted rooftop solar is because Jacobson has its contribution to be rather small.  For example, multiplying out the numbers on page 61 you will get 5.1 TW of rooftop solar and 26.7 TW of large scale solar of 300 MW size in farms, much like wind farms.  This seems reasonable since centralized solar is twice as cost effective as rooftop solar.  Since the rooftop solar is small I will omit it from these comments.

That leaves us needing 80,000 MW of new wind solar and geothermal generation just to serve California. I think an estimate of 500 miles from wind and solar resources to major load centers is reasonable.  A 500 kV transmission line is rated at about 2000 MW max power. But you don’t want to operate it at that power level because the losses are too high and there is no reserve capacity in the line to handle the first contingency problem. Therefore I will estimate we will load the new 500 kV lines to about 1500 MW on average.

So we have 80,000 MW of renewable sources widely scattered around the Western System (WECC) with each carrying 1500 MW so that we need roughly 50 new 500 kV lines of 500 miles each, for a total length of 25,000 miles.

The article assumes there is little solar power energy storage and it also assumes the wind be blowing at night.  We know for sure that the solar power is not available at night so we are nearly totally dependent on wind for night time energy.  You are going to ask about the geothermal energy.  One geothermal project I recently worked on for determining the transmission access for looked like a good project until the geothermal energy extraction failed to work.  Recently other geothermal projects have created human induced earthquakes.  Geothermal energy seem less likely today than just a few years ago.

So we are nearly totally dependent on wind energy for the night-time CA energy as envisioned in the 100% renewables by 2030.  If we plan for those few occurrences when there is no wind in the WECC system, we must interconnect WECC with the rest of the US so CA can draw power from other wind generators that do have wind (hopefully) outside the WECC area, such as the Texas coast and east of the rocky mountains where massive wind farms can be constructed. However we will need at least 40,000 MW of lines that I estimate will average 2000 miles in length. If we used 500 kV lines, we would need about 25 of these lines bridging from WECC to the US eastern grid and ERCOT and the total length would be about 50,000 miles. By 2030 we would need 75,000 miles of new 500 kV lines just to serve California with 100% renewables. Considering that we have the period from 2010 to 2030, that means we would have to construct about 4000 miles of new 500 kV lines every year from now until 2030 for the renewables plan as outlined in this article to work.

How much do these lines cost? Probably about 2 million dollars per mile.  Also, the 500 miles is just an estimate.  If you have specific projects in mind that eliminates some of the uncertainty in estimating costs.  For example the distances might be less to wind generators.  However I suspect that opposition to the wind generators unsightliness and opposition to power lines will result in longer pats for lines zig zagging around the countryside and the wind generators being not allowed anywhere on the coast, so I understand that Mexico is the desirable place for wind.  But if you were to string out 40,000 MW of wind, I bet you would find the 500 miles was not that bad a guesstimate after all.  The first few sites might be closer to load centers, but opposition is likely to drive them farther away.  The construction time for lines is mostly how long it takes to get all the ROW and get approval to build the lines.  How many years will a line be held up in hearings?  Add one year to that number of years and you have roughly the time it takes to build a new line.  Now try to build new lines across the Rockies and see how long that will take – decades I predict, if ever.

In sum, I do not believe this is achievable at all.  Therefore the concept envisioned in the SA article is not a workable plan because the transmission problems have not been addressed.  The lines aren’t going to get built.  The wind is not going to interconnect.  The SA article plan is not even a desirable plan. The environmental impact and cost would be horrendous.  Lets get realistic.

Red Necked Aussie Greenies

Guest Post by Geoff Russell. Geoff is a mathematician and computer programmer and is a member of Animal Liberation SA. His recently published book is CSIRO Perfidy.

—————————–

UK Economist Lord Nicholas Stern is the latest in a growing list, including IPCC head Rajendra Pachauri and NASA climate scientist James Hansen calling for a global shift in dietary habits towards less meat. The CSIRO has issued a new Home Energy Saving Handbook which tells people diplomatically, but unambiguously, that if they do use the CSIRO Total Wellbeing Diet, with its huge meat component, then use it for as brief a period as possible and switch to a high carbohydrate diet which has a much lower greenhouse footprint. The book also has a great section on the implications of suburban food growing, including a mention that this also tends to reduce meat consumption. This new CSIRO handbook is a long way short of the major public corporate apology that I called for in my recent book CSIRO Perfidy, but it’s an excellent start. All in all this CSIRO book is a great practical book about how people can significantly reduce their various footprints on the planet. It doesn’t fall into any of the all too common traps like considering the fuel consumption of a car, but ignoring the emissions generated during the building of the vehicle.

Stern’s call reduced animal product intake follows close on the release of a report on livestock and climate change from the Food Ethics Council in the UK(commisioned by World Wildlife Fund (WWF)). The press release announcing the report contains a statment which will probably raise the blood pressure of any meat producer. It says that the report:

Identifies a wide array of measures by which government might change consumption behaviour, …

The livestock industry can live with feel good statments about breeding for lower emitting cattle and the like, but changes to consumption, changes that would actually make a difference, that is anathema.

At the risk of boring people who know this stuff, let me quantify using an analogy that I hope will clarify. Consider a computer screen. I’m using a 19 inch 37 watt LCD. My TV is a little bigger and uses 58 watts. Most people know that huge plasma TVs can be more than a little bigger and use 10 times more power. Systems labelled home theatre can run to over 1500 watts … about half for the sound and half for the picture. Now, pause and think what would happen if somebody started making 7400 watt screens that were much the same size as normal screens. Imagine further that these screens caused serious and frequently life shortening health problems.

Would anybody defend such screens? Would anybody bother with a defence that better manufacturing could reduce their power usage by 25%?

The 7400:37 ratio is about the same as the ratio of greenhouse emissions between lean beef and pasta. The ratio is even higher if the short term (20 year) warming impact of methane is considered. A study hot off the press in Science into the indirect effects of methane calculates that adding these flow-on impacts lifts the warming due to methane by as much as 50%. This makes lean beef akin to a 10,000 watt screen.

Tim Flannery, in the longest chapter of his recent Now or Never essay (Quarterly Essay 31) has put forward a plan to massively increase global beef production … the direct equivalent of a plea to stock the planet with an abundance of 7400 watt computer screens. This has been criticised by both myself (see Quarterly Essay 32) and Peter Singer. Responding to Singer in the US edition of Now or Never, Flannery writes:

And in the beef sector, it’s been found that smaller breeds of cattle produce 25 percent less methane than standard breeds, and that the overall management of the herd has an enormous impact on the overall greenhouse gas balance of the business.

If he were consistent, Flannery should similarly allow that a 25% reduction in the power required for a 7400 watt screen should earn it a green energy saver badge.

In Perfidy, which is about far more than just the CSIRO’s dodgy diet, I examine the implications of Flannery’s call for more cattle in some detail. Firstly, it’s an impossible vision. But going with Flannery’s flight of fancy and assuming there is enough land to graze enough cattle so that most of the planet (leaving out a billion or so steadfastly vegetarian Indians) ate the same amount of beef as Australians (bearing in mind that more chicken is eaten than beef in Australia these days), we would add about another 98 mega tonnes to the annual global emissions of methane. If you are unfamiliar with the global methane budget, the current anthropogenic emissions are about 350 mega tonnes, so a 98 mega tonne injection of methane would be huge.

So, on the one side we have a growing international call to scale down the livestock sector, particularly cattle, but in Australia we either don’t report such calls (and you won’t find the Food Ethics Council paper on the Australian WWF website), or they get a brief mention on page 23 and we have high profile environmentalists like Flannery pushing in the opposite direction. One of the reasons I’ve always been on the fringe of environment groups and more comfortable in animal rights groups is that many greens (and Greens), like Flannery, seem to place the sanctity of the BBQ above the health of the planet. I have absolutely no idea what drives such people, they steadfastly refuse to follow where the evidence leads. Anybody who reads Peter Singer’s work will realise that for him and others in the animal rights camp, using information and logic to formulate ways to minimise suffering isn’t mere entertainment, but the final arbiter of action.

Which leads me to Kelly’s Bush.

Kelly’s bush is about 7 acres of bush land on Sydney’s wealthy North Shore. In the early 1970s it was threatened with development. Some regard the fight to save Kelly’s Bush as the birth of the modern Australian green activist movement. The fight was spear headed by the famous Green Bans imposed by the Builder’s Labourers Union, led by Jack Mundey. The bans began in the early 1970s, but the story I want to tell goes back a decade earlier to 1962. What happened in 1962? Yes, I know, Rachel Carson published Silent Spring, but that’s just a book, what actually happened? What actually happened was that Bob Kleberg of King Ranch in Texas bought 50,000 acres of primary rainforest along the Tulley River in north Queensland (ironically not far from where Jack Mundey grew up) and worked out how to use 50 tonne bulldozers to fell giant rainforest trees for just $20 a cleared acre. A huge rolling steel ball with spikes is dragged between the dozers on a chain and when it hits a tree it climbs. As it mounts the tree, the dozers gain leverage and can knock down anything. By 1965, the 50,000 acres (about 20,000 hectares) was gone. By the early 1970s, I’ll wager some of that Tully beef ended up in BBQs and sandwiches at Green Ban picket lines in Sydney. Meanwhile the bulldozers where shipped to Venezuela and the now perfected methods were used there and later in Brazil in an attack on the planet’s rainforests that is on-going.

Such is the story of high profile environmentalism in Australia. The real fight to preserve biodiversity should have been fought in our supermarkets, but the big green organisations, the ones with a profile high enough to have a chance at effecting major consumer change, are too busy having BBQ fundraisers and fighting for can deposits and against plastic bags. But the deliberate focus on the trivial by many in the green movement is more generally symptomatic of what passes for ethical debate in Australia. This is particularly obvious when we consider the ethics of climate change.

Back in May, The Lancet published the results of a joint study with the University College London on the health impacts of climate change.

The study contains the following map (from a 2007 study) showing the causal responsibility of climate change compared with the likely adverse health impacts. The former were measured in giga-tonnes of carbon emitted between 1950 and 2000 while the latter were measured in mortality per million of population. The geographical area of each country in the map has been transformed so that relative areas correspond to relative causes or health impacts. The malnutrition component comes from an earlier World Health Organisation modelling study and is due to a projected increase in regional droughts.

Note that this is a per-capita measure of suffering, not an absolute measure. A map showing relative absolute suffering would make the ethical responsibility even more obvious but would possibly see some of countries which are major causes of climate change totally disappear in the map of adverse impacts.

The malnutrition impacts are considered to have already started. It is of course difficult to disentangle malnutrition due to climate change from malnutrition due to other causes but a June FAO press release shows we have climbed to over a billion undernourished people, having been hovering at about 800 million between 1990 and 2003 when the wheels started to fall off the global food machine. The UN Food and Agriculture Organisation is now reporting in its 2009 State of Food Insecurity report (SOFI) that the absolute number of malnourished people has been rising since the mid 1990s.

The Lancet isn’t on my list of regularly read journals, but I thought it a little wierd that I’d never heard of this report. So I did some googling to see who covered it at the time. Who did I find? The only sizable news sources which reported on the report were: Radio Australia, The ABC (online) and The Mercury. Unsurprisingly, I found no mentions in any of the major newspapers.

Taken at face value, the maps make the asymmetry of causes and impacts abundantly clear. We in the developed world are responsible for most of the pain and suffering that will be felt predominantly (but not exclusively) in the developing world.

Humans have an extraordinarily well developed sense of fairness and justice. But it isn’t just humans who have this. A sense of fairness extends, at least, to other primates. Capuchin monkeys will refuse to work for rewards where they can see other monkeys getting more rewards for the same work. Sound familiar?

The maps plus the monkey research make it entirely unsurprising that both the Chinese and the Indians are playing hard ball in the run up to the Copenhagen climate negotiations.

Wondering why the report and the maps weren’t more widely reported in Australia, I formulated a quick hypothesis: Australians don’t care much for ethical issues. But then I thought more deeply and considered NSW’s MP John Della Bosca’s recent resignation and the blanket media coverage it received. So I modified my hypothesis. Australians treat ethics as a spectator sport, rather like football. Its great to watch a bit of biffo as long as you’re not on the receiving end of the real thing. This is supported by a few tables in How Australia Compares, a nice book of selected OECD data tables selected by Rodney Tiffen and Ross Gittins. In particular Australia is down at, or near, the bottom of the OECD countries in the income of its disabled people, the rate of children living in poverty in either single mother or two parent households, the level of unemployment benefits, and a host of other measures. This book came out in 2004 and most of the tables reflect data as of the year 2000, but I doubt much has changed. The generous country I thought I grew up in has either vanished … or perhaps it never existed.

But one aspect of the above maps worries me … the attribution of malnutrition to climate change.

Brazil doubled its cereal production between 1990 and 2003 with only a 35% rise in human population, it was awash with food. During the same period the proportion of Brazil’s cereal going to feed livestock went from 44% to 57%. Asia between 1990 and 2003 experienced a surge in livestock feeding between 1990 and 1995 going from 15% of cereals to 19%. The lower rate probably reflects the Asian preference for chicken and pork over beef. In any event, this fraction persisted until at least 2003. Indonesia and China dominate the Asian picture and both had a surge in corn production during the early 1990s, with the only beneficiaries being livestock. Total Asian cereal production, imports and and livestock feed ratios moved little between 1995 and 2003, despite a rising population. But the rising use of food for feed elsewhere in the world meant reductions in food available (and possibly affordable) to meet the short fall. The result was that undernourishment increased in Asia … exactly as the UN SOFI report finds.

Australia’s grain production goes up and down like a yo-yo so its difficult to discuss food/feed ratios on a yearly basis. But the amount of grain used as feed in 1990 was about 4 million tonnes, in 1995 it was 6 million, by 2003 it was 7.6 million and by 2006/7 it had surged to 12 million. So all up, Australians eat about 2 million tonnes, feed an increasing amount to livestock which leaves a steadily shrinking volume available for export.

The spread of western meat based diets globally has been accompanied by a spread of factory farming, obesity and chronic disease together with a change in the world’s livestock distribution. Factory farming now produces the bulk of the world’s 98 million tonnes of pigmeat and factory farms are high capital operations which demand, and can pay for, a consistent feed supply chain. They can outbid the world’s poor and turn food into feed and food producers into feed producers in exactly the same way that coffee drinkers turn food growers into coffee growers. While it is perfectly reasonable for any country to have a mix of food and cash crops, its the balance that matters.

Between 1984 and 2004 the world’s cattle population fell by 25% in the developed world but increased by a similar proportion in the developing world. This means that of the world’s 1.33 billion cattle, over a billion are in the developing world. Brazil has 190 million, Sudan and Colombia have 41 and 26 million cattle respectively and all three get a mention in the SOFI report with Brazil still having 12% undernourishment in 2004-6 despite a veritable glut of food production capacity.

Globally, this conversion of food to feed to drive increasing meat consumption accounts for the increase in undernourishment without requiring much, if any, input from climate change. As the better off eat more meat, they create a livestock industry which can outbid the poor for food.

But in Australia, our red necked BBQ culture reigns supreme. It’s impacts are felt in poor countries who can no longer buy as much of our grain because is has been siphoned off to feed livestock. Our culture is felt also in rich countries who buy our beef and get bowel cancer and heart disease as a result. We will continue to focus our ethical might on the sexual peccadillos of our politicians and our environmental muscle on plastic bags.

TCASE 2: Energy primer

Before getting entangled in the thorny bramble of sustainable energy options, I thought it helpful to arm you with a set of terminological secateurs. So TCASE #2 (recalling that TCASE = the Thinking Critically About Sustainable Energy series) is a brief primer and glossary on energy terms. This is not meant to be anything comprehensive, but it’s enough to get your technical feet wet and to understand some of the units and concepts that are liberally thrown around by those who are used to talking in the energy jargon. (If readers feel I have missed something important [no doubt], please feel free to add this to the comments, and I will also update this post to reflect the important suggestions.)

Anyway, first up, we need to understand the difference between power and energy. Let’s say you have a jug of water. It has some volume, which is the amount of water the jug holds. Now, let’s say you gradually tip out the water — the flow of water (the amount of water being poured per unit time) is a rate. Well, in caricature, the volume of water is like energy, and the flow of water is like power. Not a perfect analogy, but they never are…

Now, when measuring anything, you could use any manner of units. I’m going to consistently stick to SI (Système Internationale) units. If you want to translate back and forth (imperial, metric, nonsensic, etc.), look up the tables here. The basic SI unit of energy is the Joule. The basic unit of power is the Watt (W), which has units of Joules per second (J/s). So, a 60 W incandescent light globe uses up energy at a rate of 60 J/s, or 216,000 J per hour (60 x 3,600 = 216 kilojoules, kJ). Or, to express it another way, in one hour (h) that light would use up 60 Wh worth of energy, and in a day, it’d use 60 x 24 = 1,440 Wh, or 1.44 kWh. So, kWh are a unit of energy.

Energy comes in various forms, such as heat and electricity (the ones that are relevant to TCASE — there are also forms such as ionising radiation, light etc.). Heat (hereafter thermal) energy is considered lower quality than electrical energy — it’s less flexible and difficult to transport — but thermal energy is easier to store. Also, many power production methods, such as coal- or gas-fired, nuclear, geothermal and solar thermal power stations, generate thermal energy and then convert it to electrical energy, in a process that necessarily must throw away waste heat (roughly 2/3 of it) — first used in a practical way by Thomas Newcomen and later improved upon by James Watt. This is commonly done via a steam generator and condenser, although gas turbines are also used. Indeed, combined cycle gas turbines use both a gas turbine (Brayton cycle) and then use the waste heat to power a steam turbine (Rankine or Sterling cycle), which increases their conversion efficiency. Efficiency is strongly affected by the temperature differential, so if (for instance) your steam goes in really hot and then is water cooled, this will be more efficient than if your steam goes in at a lower temperature and then is air cooled. So air cooling saves water, but lowers your efficiency.

Wind turbines are connected (via gearing) to an electrical generator directly, and so avoid the need to first produce thermal energy. Solar photovoltaics also generate electricity without any thermal step, via the photoelectric effect. A hydro or tidal power device will generally use the flow of water to turn a turbine, rather than expanding steam or gas, and an ocean wave generator might pump water to shore at high pressure to turn a turbine. You get the idea.

An important thing to distinguish is the difference between conversion efficiency and capacity factor. You might, for instance, have a nuclear power station that has a conversion efficiency of 38%, but a capacity factor of 92%. What’s the difference? The conversion efficiency is (roughly) the efficiency with which thermal energy is converted into electrical energy through one or more steps. The capacity factor is the amount of energy a power station generates over a given length of time compared to the energy it might have produced if it had been running at full power for the whole period. There is a good explanation of capacity factor on Wiki.

Here, let’s take an example of wind turbines to better explain capacity factor. One of the largest wind turbines yet built is the Enercon E-126 (see picture), which produces a peak power of 6 MWe (that’s 6,000 kWe, where the “e” distinguishes this as electrical energy as opposed to “MWt” for thermal energy). This impressive structure has rotor (blade) diameter of 126 m, and a hub height of 198 m. Let’s say you stuck this on the west coast of the Eyre Peninsula, where it sometimes got strong wind speeds that allowed it to generate its full rating of 6 MW. Other times, the wind would be modest, weak, or calm, at which times it would be generating at less than its peak (nameplate) power. It would also shut off it the wind got too strong in a gale. Now, let’s say you tallied up the energy this turbine had generated over the course of one year at this site, and found it to be 16,820 MWh. If the turbine had generated at full power the whole time, you would have expected it to have produced 6 x 24 x 365 = 52,560 MWh. So, in this case, it’s capacity factor for the year was 16,820/52,560 x 100/1 = 32 %.

Alternatively, let’s say an AP-1000 nuclear power station was rated at 1,154 MWe, and for 11 months it was run at this power output. Then, for one month (say December) it was offline being refueled. It would generate 1154 x 24 x (365-31) = 9,250 GWh for 11 months and for December it would generate 0 GWh. It’s capacity factor would, in this example, be 9,250/10,109 x 100/1 = 91.5 %. And so on, for all the other technologies we’ll be discussing in TCASE.

So, 1 gigawatt (GW) = 1,000 megawatts (MW) = 1,000,000 kilowatts (kW) = 1 billion Watts (W). Solar panels are usually described in terms of their peak kW power. Wind turbines are (these days) usually rated in MW. Nuclear power stations are expressed in MW or GW. Almost universally, their peak (nameplate) electrical power, rather than thermal power or average power (after accounting for capacity factor), is what is reported. So watch out when converting to energy.

Finally, recall I said a W was in units of J/s? A J is a unit of energy. But why then did I start to talk about energy in kilowatt hours (kWh) etc.? Well, this is often a convenient way to express energy (David Mackay chose to use this as his standard), as it’s easy to mentally switch back and forth between power and energy (though there is also the potential to get confused!). Also, J is too small to be of much practical value. But the megajoule (MJ) is a useful value for expressing the energy content of a litre of liquid fuel (for instance), and the petajoule (PJ) and exajoule (EJ) are sufficient for expressing the energy use of nations and civilisations. For instance, the primary energy use (thermal and electrical) of the global human enterprise in 2007 was (very approximately) 500 EJ, which is 138,890 TWh (terawatt hours) — where 1 TW = 1,000 GW. I’m sure by now you’re getting the hang of this!

I like to use EJ and TW when expressing really large energy budgets and power demands — which, incidentally, is the topic of TCASE #3.

Thinking critically about sustainable energy (TCASE) 1: Prologue

This is the first post in what is planned to be an extended series, ‘Thinking critically about sustainable energy‘ (henceforth TCASE #). As explained in my previous blog entry, A necessary interlude, this series will look in detail at the issues confronting renewable and nuclear energy, with an aim to break down the often complex and multifaceted critiques and promotions being made about various energy generation technologies into simpler, single-issue chunks, which can be more readily pinned down and understood.

I will also profile some of the less well-developed low-carbon technologies, such as tidal, wave, microalgae, and geothermal, as well as nuclear fusion, fusion-fission hybrids, travelling wave reactors etc. and speculate on their possible future roles. I hope in this way that I’ll be able to reinforce people’s understanding of why I no longer hold renewable energy to be a primary solution — and yet, by the same yardstick of maintaining intellectual honesty, acknowledging that I’ll also keep an open mind to unconsidered possibilities and caveats that are raised by commenters (be these against nuclear energy, and/or for renewables). Indeed, I’ll also discuss critically the social and technical impediments facing nuclear power adoption and the Generation III/IV synergy.

First up, a little history of the evolution of my thought on this topic, as documented my professional research and in the archives of this blog.

My scientific training and subsequent research career has, in various ways, involved the use of ’systems models‘. My published works have been largely in the area of ecological complexity, stochastic model evaluation, palaeoecology and statistical inference. So I’ve always had strong interest in how small pieces of a puzzle can fit together to make up the big picture — including trying to: (i) understand and quantify the relative sensitivity, redundancy and irreplaceability of different components; (ii) determine the degree to which they are additive, complementary or substitutable, and (iii) assess whether synergistic interactions can result in amplifying benefits or other emergent non-linear properties. As it turns out, the assessment of such system properties is also rather important for understanding how an integrated energy supply can function effectively.

My interest in energy systems is relatively new, but now constitutes somewhat of an obsession! My first post on topic was a guest blog by Stewart Taggert: “Australia can be a clean energy superpower“. This was followed by the post “Climate ripe for transformative change” in which I said:

The decision to invest heavily – and rapidly – in renewable energies like geothermal (hot rocks), solar thermal (desert mirrors), wave and wind power, and rooftop photovoltaic systems, is a no brainer. These technologies offer the only way to achieve an ongoing, growing energy supply.

and “Thinking big and fast on renewable energy” where I extolled our great clean energy resources:

But if Australia has vision, plays its cards right, and becomes a leader in the global climate solution, we could be humming with global exports of clean energy as world-leading discoveries make exploitation of unlimited energy resources ever cheaper. Australia is incredibly well placed among developed countries to move completely to renewable energy. We have huge, unexploited solar resources in our continental interior akin to the oil fields of the Middle East in the early 20th Century.

It is particularly instructive to look at a couple of the critiques I published at the bottom of that last piece, and my ‘answer’ to them at the time. Ahhh, it’s fun to reflect on the naivety of one’s youth…

Anyway, my focus at this point was pointedly directed at carbon emissions reduction (clean energy was just a means to an end), and it was obvious to me that the logical path to achieve this was renewable sources such as solar and wind power. I was coming at this issue from a genuine concern for eliminating carbon-based energy, and was overwhelmed by a sense of frustration, because I couldn’t understand why the ‘clean energy revolution’ wasn’t happening. Surely, all we had to do was put a price on carbon, to reflect the damage fossil fuel combustion was causing to the environment, and big things would start to happen! Bottom line is, no one could look back over those early posts and imagine that I came at this issue with anything other than a firm conviction that renewable energy was the answer. Indeed, I hadn’t given much thought to nuclear power at this point, not because I was ever ideologically ’anti-nuclear’ — I had simply accepted the ‘peak uranium’ argument and not thought much more about it, as this comment I made back in Dec 2008 indicates.

Then, reality bit me, and it hurt. I remember I was sent an early version of Trainer’s thesis, and against all reason (’what nonsense is this?‘ I recall first thinking), I read the damned thing. Somewhat crestfallen, yet also morbidly fascinated, I followed up, reading ‘The Solar Fraud‘ (the only other book on this topic of renewable limits, according to Trainer’s piece) and then a bookshelf worth of other tomes on this general topic, including ‘Sustainable Energy: Without the Hot Air‘ and ‘Prescription for the Planet‘ (kicking off my nuclear education in earnest),  followed by various technical analyses, IPCC WG III, blogs, etc. My first post on this blog on nuclear power was on 28 Nov 2008, 3 months after it has been launched. My transformation of thought had begun in earnest, and was reinforced by the work of people such as Peter Lang. The TCASE series is the next, more logically formalised, step in this process.

As a quantitative scientist with a bent towards statistics and models, I was willing to let preconceptions go if the evidence was there that I was wrong. Although it is often misused by those who actually do the complete opposite, the famous quote from Keynes here is apt: “When the facts change, I change my mind. What do you do, sir?” — although in this instance, it wasn’t the facts that changed as much as my knowledge and understanding of them. So begins a journey with TCASE to look critically at sustainable energy, in all forms. It is written in the hope of providing a resource for others to understand the magnitude of the challenge we face in eliminating our dependence on coal, oil and gas, to signpost the blind alleys to avoid, and to arrive at a rational conclusion as to what the most likely path(s) to success might be.

Addendum: Here is an updated version of the chart profiled in this post.

Solar realities and transmission costs – addendum

Peter Lang’s ’solar realities’ paper and its associated discussion thread has generated an enormous amount of interest on BraveNewClimate (435 comments to date). Peter and I have greatly appreciated the feedback (although not always agreed with the critiques!), and this has led Peter to prepare: (a) an updated version of ‘Solar Realites’ (download the updated v2 PDF here) and (b) a response paper (download PDF here). Below I reproduce the response, and also include Peter’s sketched analysis of the scale/cost of the electricity transmission infrastructure (PDF here).

———————————————–

Comparison of capital cost of nuclear and solar power

By Peter Lang (Peter is a retired geologist and engineer with 40 years experience on a wide range of energy projects throughout the world, including managing energy R&D and providing policy advice for government and opposition. His experience includes: coal, oil, gas, hydro, geothermal, nuclear power plants, nuclear waste disposal, and a wide range of energy end use management projects)

Introduction

This paper compares the capital cost of three electricity generation technologies based on a simple analysis. The comparison is on the basis that the technologies can supply the National Electricity Market (NEM) demand without fossil fuel back up. The NEM demand in winter 2007 was:

20 GW base load power;

33 GW peak power (at 6:30 pm); and

25 GW average power.

600 GWh energy per day (450 GWh between 3 pm and 9 am)

The three technologies compared are:

1. Nuclear power;

2. Solar photo-voltaic with energy storage; and

3. Solar thermal with energy storage

(Solar thermal technologies that can meet this demand do not exist yet. Solar thermal is still in the early stages of development and demonstration. On the technology life cycle Solar Thermal is before “Bleeding edge” – refer: http://en.wikipedia.org/wiki/Technology_lifecycle).

This paper is an extension of the paper “Solar Power Realities” . That paper provides information that is essential for understanding this paper. The estimates are ‘ball-park’ and intended to provide a ranking of the technologies rather than exact costs. The estimates should be considered as +/- 50%.

Nuclear Power

25 GW @ $4 billion /GW = $100 billion (The settled-down-cost of nuclear may be 25% to 50% of this figure if we reach consensus that we need to cut emissions from electricity to near zero as quickly as practicable.)

8 GW pumped hydro storage @ $2.5 billion /GW = $20 billion

Total capital cost = $120 billion

Australia already has about 2 GW of pumped-hydro storage so we would need an additional 6 GW to meet this requirement. If sufficient pumped hydro storage sites are not available we can use an additional 8GW of nuclear or chemical storage (e.g. Sodium Sulphur batteries). The additional 8 GW of nuclear would increase the cost by $12 billion to $132 billion (the cost of extra 8 GW nuclear less the cost of 8 GW of pumped hydro storage; i.e. $32 billion – $20 billion).

Solar Photo-Voltaic (PV)

From ‘Solar Power Realities’ :

Capital cost of PV system with 30 days of pumped-hydro storage = $2,800 billion. (In reality, we do not have sites available for even 1 day of pumped hydro storage.)

Capital cost of PV system with 5 days of Sodium Sulphur battery storage = $4,600 billion.

Solar Thermal

The system must be able to supply the power to meet demand at all times, even during long periods of overcast conditions. We must design for the worst conditions.

We’ll consider two worst case scenarios:

1. All power stations are under cloud at the same time for 3 days.

2. At all times between 9 am and 3 pm at least one power station, somewhere, has direct sunlight, but all other power stations are under cloud.

Assumptions:

The average capacity factor for all the power stations when under cloud for 3 days is 1.56 % (to be consistent with the PV analysis in “Solar Power Realities”; refer to Figure 7 and the table on page 10).

The capacity factor in midwinter, when not under cloud, is 15% (refer Figure 7 in “Solar Power Realities”).

Scenario 1 – all power stations under cloud

Energy storage required: 3 days x 450,000 MWh/d = 1,350,000 MWh

Hours of the day when energy is stored (9 am to 3 pm) = 6 hours

Average power to meet direct day-time demand = 25 GW

Average power required to store 450,000 MWh in 6 hours = 75 GW

Total power required for 6 hours (9 am to 3 pm) = 100 GW

Installed capacity required to provide 100 GW power at 1.56% capacity factor (say 6.24% capacity factor from 9 am to 3 pm) = 1,600 GW.

Total peak generating capacity required = 1,600 GW

If the average capacity factor was double, the installed capacity required would be half. So the result is highly sensitive to the average capacity factor.

Scenario 2 – at least one power station has direct sun at all times between 9 am and 3 pm

One power station provides virtually all the power. The other power stations are under cloud and have a capacity factor of just 1.56%.

Energy storage required for 1 day = 450,000 MWh

Hours of the day when energy is stored (9 am to 3 pm) = 6 hours

Average power to meet direct day-time demand = 25 GW

Average power required to store 450,000 MWh in 6 hours = 75 GW

Total power required = 100 GW.

The capacity factor in midwinter, when not under cloud, is 15% (refer Figure 7 in “Solar Power Realities”).

Installed capacity required to provide 100 GW power at 15% capacity factor (60% capacity factor from 9 am to 3 pm) = 167 GW.

But the clouds move, so all the power stations need this generating capacity.

To maximise the probability that at least one power station is in the sun we need many power stations spread over a large geographic area. If we have say 20 power stations spread across south east South Australia, Victoria, NSW and southern Queensland, we would need 3,300 GW – assuming only the power station in the sun is generating.

If we want redundancy for the power station in the sun, we’d need to double the 3,300 GW to 6,600 GW.

Of course the power stations under cloud will also contribute. Let’s say they are generating at 1.56% capacity factor. Without going through the calculations we can see the capacity required will be between the 1,600 GW calculated for Scenario 1 and the 3,300 GW calculated here. However, it is a relatively small reduction (CF 3% / 60% = 5% reduction), so I have ignored it in this simple analysis .

So, Scenario 2 requires 450,000 MWh storage and 3,300 GW generating capacity. It also requires a very much greater transmission capacity, but we’ll ignore that for now.

Costs of Solar Thermal with storage

NEEDS , 2008, “Final report on technical data, costs, and life cycle inventories of solar thermal power plants” Table 2.3, gives costs for the two most prospective solar thermal technologies. They selected the solar trough as the reference technology and did all the calculations for it. The cost for a solar trough system factored up to 18 hours storage and converted to Australian dollars is:

This would be the cost if the sun was always shining brightly on all the solar power stations. This is about five times the cost of nuclear. However, that is not all. This system may have an economic life expectancy of perhaps 30 years. So it will need to be replaced at least once during the life of a nuclear plant. So the costs should be doubled to have a fair comparison with a nuclear plant.

In order to estimate the costs for Scenario 1 and Scenario 2 we need costs for power and for energy storage as separate items. The input data and the calculations are shown in the Appendix.

The costs for the two scenarios (see Appendix for the calculations) are:

Summary of cost estimates for the options considered

The conclusion stated in the “Solar Power Realities” paper is confirmed. The Capital cost of solar power would be 20 times more than nuclear power to provide the NEM demand. Solar PV is the least cost of the solar options. The much greater investment in solar PV than in solar thermal world wide corroborates this conclusion.

Some notes on cloud cover

A quick scan of the Bureau of Meteorology satellite images revealed the following:

This link provides satelite views. A loop through the midday images for each day of June, July and August 2009, shows that much of south east South Australia, Victoria, NSW and southern Queensland were cloud covered on June 1, 2, 21 and 25 to 28. July 3 to 6, 10, 11, 14. 16, 22 to 31 also had widespread cloud cover (26th was the worst), as did August 4, 9, 10, 21, 22.. This was not a a rigorous study.

Also see the BOM Solar Radiation Browse Service for March and April 2002 (the data on this site only goes up to 14 April 2002). Notice the low solar radiation levels for 25 to 30 March and 8 to 12 April 2002 over the area we are looking at. The loop animation can be viewed here.

Some comments on Future Costs?

How much cheaper can solar power be? NEEDS figure 3.7, p31 suggests that the cost of solar thermal may be halved by 2040.

How much cheaper can nuclear be? Hanford B, the first large reactor ever made, was built in 15 months, ran for 24 years, and its power was expanded by a factor of 9 during its life. If we could do that 65 years ago, for a first of a kind technology, what could we do now by building on experience to date if we wanted to put our mind to it. Is it unreasonable to believe that, 65 years later, we could build nuclear power plants, twenty times the power of the first reactor, in 12 months, for 25% of the cost of current generation nuclear power stations?

Appendix – Cost Calculations for Solar Thermal

The unit cost rates used in the analyses below were obtained from: NEEDS, 2008, “Final report on technical data, costs, and life cycle inventories of solar thermal power plants“, p31 and Figure 3.7.

Note that, although this table includes calculations for the cost of a system with 3 and 5 days of continuous operation at full power, the technology does not exist, and current evidence is that it is impracticable. The figure is used in this comparison, but is highly optimistic.

———————————————–

Capital Cost of Transmission for Renewable Energy

Following is a ‘ball park’ calculation of the cost of a trunk transmission system to support wind and solar farms spread across the continent and generating all our electricity.

The idea of distributed renewable energy generators is that at least one region will be able to meet the total average demand (25 GW) at any time. Applying the principle that ‘the wind is always blowing somewhere’ and ‘the sun will always be shining somewhere in the day time’, there will be times when all the power would be supplied by just one region – let’s call it the ‘Somewhere Region’.

The scenario to be costed is as follows:

Wind power stations are located predominantly along the southern strip of Australia from Perth to Melbourne.

Solar thermal power stations, each with their own on-site energy storage, are distributed throughout our deserts, mostly in the east-west band across the middle of the continent.

All power (25GW) must be able to be provided by any region.

We’ll base the costs on building a trunk transmission system from Perth to Sydney, with five north-south transmission lines linking from the solar thermal regions at around latitude 23 degrees. The Perth to Sydney trunk line is 4,000 km and the five north-south lines average 1000 km each. Add 1,000 km to distribute to Adelaide, Melbourne, Brisbane. Total line length is 10,000km. All lines must carry 25GW.

Each of the double circuit 500kV lines from Eraring Power Station to Kemps Creek can transmit 3,250MW so let’s say we would need 8 parallel lines for 25GW plus one extra as emergency spare.

The cost of the double circuit 500kV lines is about $2M/km.

For nine lines the cost would be $18M/km.

So the total cost of a transmission system to transmit from the ‘Somewhere Region’ to the demand centres is 10,000km x $18M/km = $180 billion

The trunk transmission lines might represent half the cost of the complete transmission system enhancements needed to support the renewable generators.

Just the cost of the trunk transmission lines alone ($180 billion) is more than the cost of the whole nuclear option ($120 billion).

Eraring to Kemps Creek 500kV transmission line. Each of the double circuit 500kV lines from Eraring to Kemps Creek can carry 3250MW. The 500kV lines are double circuit, 3 phase, quad Orange, i.e.2 circuits times 3 phases times 4 conductors per bundle, i.e. 24 wires per tower. Orange is ACSR, Aluminium Conductor Steel Reinforced, with 54 strands of 3.25mm dia aluminium surrounding 7 strands of 3.25mm dia steel. Roughly 1/3 of the cost of a line is in the wires, 1/3 in the steel towers and 1/3 in the easements required to run the line.

Is Our Future Nuclear?

Transcript: Is Our Future Nuclear?

Broadcast: 28/08/2009

[YouTube video here],

Reporter: Mike Sexton

IAN HENSCHKE, PRESENTER: At this week’s AGM, the State Liberals voted to debate nuclear power’s potential the cut carbon emissions. But with Labor demanding debate be shut down and the Liberal leader saying the vote wasn’t binding, discussion seems doomed. But while the politicians won’t debate, others will, with some senior academics saying the future depends on nuclear power. Mike Sexton reports.

MIKE SEXTON, REPORTER: Australians are using more and more electricity, most of it created by coal generators that emit carbon. In simple terms, most scientists believe the more air conditioners in use, the hotter the planet gets.

BARRY BROOK, UNI. OF ADELAIDE: That obviously leads you to consider well, what are the possible solutions? We can look at adaption to climate change, but ultimately we’ve got to stop the process from running out of control.

MIKE SEXTON: Professor Barry Brook is director of the Research Institute for Climate Change and Sustainability at the University of Adelaide. He’s running his slide rule over the options Australia has for generating electricity while reducing emissions, and believes despite the abundance of wind, sunshine and hot rocks, renewable energy will not power us through the 21st Century.

BARRY BROOK: Looking hard at renewable energy, there are a lot of limitations, especially in terms of energy storage and energy back up that make it extraordinarily implausible, according to my view and that of many others, that it could supply most of our power needs in the future, which, for someone who’s really concerned about climate change impacts is a pretty disappointing conclusion.

MIKE SEXTON: Which is why Professor Brook believes the answer lies in that other abundant South Australian resource: uranium.

BARRY BROOK: We need to find a technology that has the characteristics of coal but is cheaper than coal. Nuclear power, especially fourth generation nuclear power, offers that prospect. Now if we can’t find, develop, commercialise and deploy on a large scale that sort of technology, I think we have a very slim chance of avoiding major climate change impacts.

DAVID NOONAN, AUST. CONSERVATION FOUNDATION: Nuclear is first far too slow and far too expensive. It would be the least effective option for Australia to look to in terms of addressing climate change and greenhouse gas emission issues. We are now on the path toward a renewable energy future.

MIKE SEXTON: Barry Brook isn’t alone in his view. Others such as Tim Flannery agree with him. But the opinion has opened a divide among the environmental movement comparable to the one among scientists who are climate change believers or sceptics. David Noonan from the Australian Conservation Foundation has long campaigned against nuclear power and uranium mining and believes he represents the views of most environmentalists.

Have you seen a shift in this debate?

DAVID NOONAN: No I haven’t, in the sense that there is no group environment group, state, national or international, that’s supporting nuclear power. Some individuals have expressed a view, but that’s not reflected by the environment movement.

MIKE SEXTON: Opponents of nuclear power point to the catastrophes at Three Mile Island and Chernobyl as reasons why the technology shouldn’t be used. But proponents argue those plants were so called first and second generation reactors and that new technologies make repeats unlikely.

BARRY BROOK: It’s a bit like, to take an analogy, comparing the A 380 aircraft to the Hindenburg and saying well, Hindenburg blew up in 1933, therefore aviation is an inherently unsafe technology and we shouldn’t pursue it. I mean, technologies move on; people learn from their mistakes.

MIKE SEXTON: While Australia has no plans for nuclear power, according to Australian Uranium Association, 50 other countries do, and that’s on top of the 31 countries that already have reactors.

MICHAEL ANGWIN, AUST. URANIUM ASSOC: We had some economic research done for us a year or so ago and that showed that an increase in the demand for nuclear power using some fairly conservative assumptions would increase demand for Australia’s uranium to somewhere between 30,000 and 40,000 tonnes a year. And that’s three to four times what we currently export. And you put that together with the expansion of South Australia’s uranium industry and there’s a very significant opportunity there for South Australia.

MIKE SEXTON: At the moment, nuclear power station don’t just use what is mined in South Australia. Unlike coal, which is mined and used in a power plant, unprocessed uranium known as yellowcake, has to be enriched overseas, with only about three per cent of it ending up as fuel rods. Some in business believe Australia should build an enrichment plant to value add to the uranium export. But the industry itself says for a number of reasons including security that’s unlikely.

MICHAEL ANGWIN: Most of the world’s thinking these days about enrichment in fact is not to spread it round further, but to concentrate it.

MIKE SEXTON: Many planned new reactors are so-called third generation models which last longer and are more efficient. But Barry Brook says the revolution he hopes will cool the planet will come from so called fourth generation nuclear power plants, which are still a theory, as one is yet to be built.

BARRY BROOK: This is the technology of the future. And it solves a lot of other problems that are currently associated with nuclear power. One of the biggest is, we’ve generated all of this nuclear waste in the form of spent fuel that we have to manage for 100,000 years. Well the rather neat thing about the new technology, which is called generation four nuclear power is that it takes that waste and uses that as fuel.

MIKE SEXTON: Generation four reactors would also run on mined rather than enriched uranium of which there’s a global stockpile. So if they would come online, the need for yellowcake would diminish dramatically.

MICHAEL ANGWIN: At first as we have to go through generation three technology, and as far as we can see at the moment, the demand for uranium consequent upon the demand for nuclear power makes the outlook for our industry very good.

MIKE SEXTON: David Noonan believes there are security concerns about generation four reactors because they produce and use plutonium, which is also the principal ingredient in nuclear weapons.

DAVID NOONAN: These are breeder reactors; they produce plutonium and that maximises the risks of weapons and of nuclear proliferation. And we can’t be proposing to address the hazards of climate change by introducing and relying on the risks in nuclear weaponry.

MIKE SEXTON: Whether Australia ever embraces nuclear power remains to be seen, but the debate at least is generating plenty of heat.

Australia’s weird winter

Guest post by Blair Trewin. Blair is a senior climatologist at the Bureau of Meteorology’s National Climate Centre. He recently took the lead in writing the Special Climate Statement, Exceptional winter heat over large parts of Australia, issued 26th August 2009, updated 1st September 2009.

————————————-

Australia has just experienced an exceptionally warm August. Almost the entire country experienced above-average temperatures during the month, but the warmth was most extraordinary in the subtropics. Over most of the southern Northern Territory and the southern half of Queensland (away from the coast), maximum temperatures for August were more than 5°C above the long-term average. Maximum temperatures were the highest on record for August over 49% of Australia.

Averaged over Australia as a whole, maximum temperatures were 3.20°C above the long-term August average, and daily mean temperatures (day and night combined) were 2.47°C above average. Both values are the highest on record for August by close to a degree. In terms of how far the month was above normal, the maximum temperatures in August 2009 are also the highest on record for any month, breaking the record of +3.11°C set in April 2005; the daily mean temperatures rank second behind April 2005.

The month was marked by some individual days which were exceptionally hot for August, especially in northern NSW and Queensland. State records were set for August in both states (37.8°C at Mungindi and 38.5°C at Bedourie respectively). Perhaps more exceptional were the margins by which some records were broken, and the number of days on which previous records were exceeded. Collarenebri broke its pre-2009 August record by 5.4°C, and numerous other locations, including Murwillumbah, Moree, Gatton, Miles and Taroom, broke August records by 4°C or more. Such margins are not unheard of at exposed coastal sites – where everything has to go right to achieve an extreme high temperature (not only having a very hot air mass, but having the wind in the right direction to prevent conditions being moderated by sea breezes) – but are virtually unknown at inland locations.

Many locations exceeded pre-2009 August records on five or more days. An especially striking example was Windorah in western Queensland, which prior to 2009 had never reached 35°C in August. In 2009 it happened seven times, and their August record was lifted six times, eventually peaking at 38.0°C on the 29th.

The extremely warm August combined with generally above-average (but not record-breaking) temperatures in June and July to give record or near-record winter temperatures in many areas. Australian daily mean temperatures for winter (1.33°C above average) fell just 0.01°C short of the 1996 record, and maximum temperatures surpassed the record set in 2002. NSW, Victoria and South Australia all had their warmest winters on record, which may come as a surprise to residents of the latter two states, in a season which was distinguished more by an almost complete absence of significant cold than by any major warm extremes.

In terms of weather systems, the month was marked by a persistent high-pressure ridge over the subtropics, preventing cooler air from penetrating from the south into central and northern Australia (until the last two days of the month, by which time it was too late to make much difference). Pressures were also well below normal south of Australia, resulting in very strong and persistent westerlies south of Australia (which made it an extremely wet month in Tasmania). An interesting comparison exists with October 1988, which had very similar pressure patterns, and was also dry over the mainland and very wet in Tasmania. In October 1988 Australian mean temperatures were 2.16°C above average, which was a record at the time (it now ranks fourth). The difference of 0.31°C between the two months is close to the size of the warming trend over Australia in that 21-year period, and suggests that the long-term background warming trend is playing a role in increasing the frequency of high temperature extremes of the type seen in August 2009.

Solar thermal questions

To round out the controversial critique of solar power started here, I reproduce below the most detailed critical analysis I’ve read on solar thermal electricity. It’s written by a University of NSW academic, Ted Trainer. I’d strongly encourage you to read his full 44-page set of arguments on the inability of renewable energy to sustain an energy intensive society (an earlier version of which was reviewed last year on BNC — this provides an updated summary of his 2007 peer-reviewed book on this topic, published by Springer).

For context Ted and I agree on many things, but not all. We both acknowledge the seriousness of the climate crisis and the magnitude of the sustainability problems caused by humanity’s overexploitation of natural environments. We differ in that Trainer sees only one viable solution — a rapid, planet-wide ‘power down’ of civilisation to some ’simpler way’ (read here for his well-mapped-out thesis).

In the past year Tom Blees and I have exchanged a number of emails with Ted, in which we’ve talked about Generation IV nuclear power (IFR in particular), proposing it as a potential ‘uranium-thorium bullet’ to solve the energy crisis — and, as a result, providing the clean energy to solve a whole host of global problems such as climate change, water supply, agricultural sustainability and repairing the damage we’ve inflicted on natural systems. To his credit, Ted has looked at my arguments seriously, and has come up with a range of questions on Gen IV nuclear on which he requires ‘clear and convincing information’. As such, in a future post on BNC, I intend to address his nuclear critiques. But that’ s for another day.

The examination of solar thermal electricity given below is quite detailed, yet necessarily incomplete. Reliable data are simply lacking on many critical points. At the foot of this post, I list some key knowledge gaps on which Ted seeks further data. Perhaps you can help. For now, read on!

———————————————-

SOLAR THERMAL ELECTRICITY (for the reference list, see here)

Ted Trainer

The major drawback for renewable energy is the inability to store electricity from intermittent sources.  Solar thermal technologies are especially valuable because they can store heat and use it to generate electricity when it is needed.  Some believe this capacity will be the key to enable renewable energy sources to meet all electricity needs (e.g., Trieb, undated, Czisch, 2004), for example plugging gaps left by PV and wind.

Solar thermal systems are best suited to the hottest regions and it is not clear how far into the mid latitudes they can be effective, apart from via very long transmission lines.  They seem to be especially doubtful in winter, even in the best locations.  (For a more detailed discussion of solar thermal’s limits and potential see Trainer, 2008.). Trough systems will be considered first, then dishes.

Troughs

The winter electrical output for the US SEGS VI trough system is reported at about 20% of summer output. (NREL, personal communication.) Modelling for Central Australia, possibly the best solar thermal location in the world, by Odeh, Behnia and Morrison (2003) produces a figure closer to 12%.

The SEGS VI plant with its north-south troughs was not designed to maximise winter performance.  Arranging the troughs on an east-west axis, as distinct from the usual north-south axis, would raise the winter/summer ratio for energy entering a trough. (“Polar axis” alignment of troughs enables maximum energy yield, but is not feasible for large scale power generation.)  However even in good solar thermal regions the performance of east-west troughs in winter (and summer) is relatively low, compared with the summer and annual average performance of north-south troughs.  This is evident in Figure 1 from Odeh, Behmia and Morrison.  Summer thermal energy (not electrical output) entering a NS trough at Alice Springs would be 780 MJ/m/month, (in this document  “m” represents square metre) whereas in winter from and EW trough it would be 430 MJ/m/month, or 4 kWh/m/day.

The radiation data given by RREDC (undated), Meteonorm and ASRDHB, 2005,  point to the same general conclusion.  These sources indicate that Alice Springs is a better location than Egypt, receiving possibly 50% more solar energy per metre in winter.  It also seems to be a little better than the SW US.  Thus if solar thermal technologies are problematic in winter at Alice Springs they are not likely to be viable in the US or for Europe.

A critical problem for solar thermal systems is what proportion of collected heat is above the threshold level required for generation of sufficient steam pressure.  In regions where radiation is low to moderate, considerable heat energy could be collected without enabling generation of a significant amount of electricity.  For SEGS VI radiation appears to have to reach 700 W/m (DNI or direct normal irradiation, not global radiation) before generation becomes moderate, and at 500 W/m it is only about 33% of maximum.  (NREL, undated, Jones, et al., 2003, Figs. 5 and 14.) Thus if east-west trough collects 4 kWh/m/d, as Fig. 1 from Odeh, Behnia and Morrison indicates, not all of it will be at a sufficient intensity to generate electricity.

ASRDHB data show that for Alice Springs in winter the intensity of DNI per square metre entering an east-west trough averages only 408 W/m, over a 12 hour period.  It is over 700 W/m for about 7 hours.  Fig 3 from Odeh, Behnia and Morrison shows that at Alice Springs 26% of DNI received over a year is under 500 W/m and 18% under 350 W/m.  These figures suggest that the 4 kWh/m/d entering the trough is a misleading indication of electricity likely to be generated and that the actual output could be less than half this amount.

More direct evidence comes from the SEGS VI record.  Hayden (2004, p. 190 .) reports that the 2.3 million square metres of collectors average 77 MW over a year, which corresponds to a continuous flow of 33 W/m.  The above evidence is that winter performance is about 30% of the average performance, which is a solar to electricity efficiency of 10.7%.  This suggests that the winter figure would be a 24 hour average c.13 W/m.

From this very low gross output a number of factors must be deducted, the main two being the energy required to build and run the plant.  The latter energy losses, mostly for pumping fluid through the absorber, are given by Sargent and Lundy (2003, Section 4 – 3) at 17% p.a., although they estimate that in future the figure will be under 10%.

The embodied energy cost, i.e., the amount of energy needed to build the power plant, is reported by Dey and Lenzen at c. 4% of gross output for a plant of normal size in normal conditions.  However a plant capable of delivering 1000 MW in winter would have to be 2.5 times as large as one capable of this output as an annual average, so its embodied energy cost would be that much higher.

(It would then generate much more than 1000 MW in summer and the ratio of embodied cost to total output would remain c. 4%, but a problem would then be that summer output would be far in excess of demand. On problems in storing such a surplus as hydrogen see below.)

The embodied energy cost analysis of solar thermal systems must also take into account the energy cost of building and maintaining the long distance transmission lines, e.g., from North Africa to North West Europe and of transforming from DC to AC power.  The lines might add one-third to power plant dollar cost.  (Czisch, 2004.)

The loss of energy from solar thermal storage is low but has been estimated by Sargent and Lundy as .9%.

Finally, the loss of energy in the very long distance transmission has to be taken into account, e.g., from Egypt to NW Europe.  This could be 15% of gross output.

Some of these numbers are uncertain but when combined they indicate that the total energy loss might be 35% of the meagre gross output, meaning that a net delivered amount well under 10 W/m might reach users in winter.  If so plant capable of delivering 1000 MW in winter would need 100+ million square metres of collection area.  At the estimated SEGS cost of $800/m (i.e., per square metre, not per kW)) the plant would cost $80 billion. (Trainer 2008

More confident data on trough performance in winter would be desirable here, but troughs would not seem to be viable.  (Heydon’s account comes to a similar conclusion.)  Note that the vision of abundant winter supply to Europe via troughs would involve harvesting radiation at about 55 degrees from the vertical.

Dollar costs.

Sargent and Lundy (2003) put the capital cost of solar thermal plant at $(US)4,589/kW ($(A6,556) for the “near term future” (including heat storage, which reduces required generator capacity and cost, by enabling the generation rate to be levelled out.)  NREL say the 2003 equivalent price of the SEGS plant is $(US)7,700.  These figures are to be compared with $(A)3,700 million for coal plant plus fuel (early 2000s price) over plant lifetime.  These figures are for peak outputs and the average output from a coal plant is c. .8 of peak whereas for a solar thermal plant it is around .25 of peak capacity (in the best locations).  Thus capital cost per gross kW delivered on average (as distinct from peak) from solar thermal plant would be over 7.5 times as great as for coal including fuel.  (See Trainer, 2007, Chapter 3.)  Transmission lines from the Sahara to Europe under the Mediterranean Sea would probably add more than 33% of generating plant capital costs. (Czisch, 2001, 2004) indicating a multiple of 10.  Note that these figures are not for plant large enough to deliver well in winter and for SEGS VI this factor might multiply by a further 2.5.  Note also that dish costs are at presently much higher than trough costs.

Again future materials, energy and construction costs are likely to be far higher than at present so these figures are not very meaningful guides to future viability.

Water pre-heating.

A solar thermal plant near Sydney, NSW, some 34 degrees south, has been constructed to pre-heat water for a coal-fired power station. ( Mills, Le Lievre and Morrison, 2000.) This is sometimes taken to show that solar thermal systems are viable in the mid latitudes.  However this system delivers heat at about half the temperature required in coal-fired power stations, and therefore does not have to concentrate solar radiation intensely. The absorber is about 1 metre wide and therefore reflectors can be wide with little curvature.  Thus the capital cost is quite low.  These features indicate that this plant is not a good guide to the effectiveness or cost of solar thermal plant at this latitude that would generate electricity without augmenting fossil fuel power generation.  In a world that did not exceed safe greenhouse limits there could be few if any fossil fuel plants. Also the performance of the system falls markedly in winter as the above discussion would lead one to expect.

Dishes.

Dishes collect more energy in winter because they can be pointed directly at the sun, but there are two significant drawbacks.  Their dollar costs are reported as being 2 – 4.5 times those of troughs (Sandia, undated), although costs will surely fall considerably with further development and mass production.

The data I have been able to access indicates somewhat surprisingly low but useful winter output from dish–Stirling devices.  Some US dishes seem to have an average 24 hour flow equivalent of around 20 – 30 W/m (Davenport, 2008.)  An output plot for the Mod dish-Stirling device shows that the January average flow (averaged over 24 hours) was c. 18 W/m, and for December, 22 W/m.  Commonly published power curves show that at 700W/m output falls to around half peak output.

However this is not very relevant to our problem.  If solar thermal systems are to provide electricity 24 hours a day, and also to solve the general intermittency problem set by other renewables, then heat must be stored.  This means that the efficiencies will be much lower than those represented in the literature on dishes, which almost entirely deals with the direct generation of electricity via dish-Stirling systems. Dishes are not well suited to large scale heat collection.

Trough systems transfer heat long distances to the power block mostly through the absorber pipes, which are heated as they collect radiation (nevertheless 4% is lost, according to Sargent and Lundy, 2003).  With a dish system this would not be so and either very long pipe distances would have to be insulated and would still lose much heat energy or many small generators would have to be located close to groups of dishes. (The equivalent of a 1000 MW plant in winter would involve tens of thousands of big dishes; below.)  For these reasons the European and US dish developers I have contacted regard the use of dishes to collect heat as not being viable. (Personal communications.)

Kenaff’s pioneering work at White Cliffs, Australia on dish-steam generation (without storage) achieved 9.1% annual solar to electricity efficiency.  The ANU Big Dish has a 13.9% efficiency, which it is expected can rise to 19% in future.  (Note that this is  a measure at a point in time under ideal conditions, not a measure of recorded annual average performance; which would be considerably lower, e.g., because of dust build up, warm up delay after cloud, etc. and winter performance.)  I do not have figures on the winter performance of either system.  If we assume 5 kWh/m/d radiation, the White Cliffs 15% loss of heat between collector and engine room, the 19% heat to electricity generation efficiency Lovegrove expects, and an 8% energy cost for pumping (the trough figure), then output might correspond to a gross 31 W/m 24 hour average flow.   However this assumes 1000/m radiation and in winter radiation barely rises above 700 W/m, which for dish-Stirling generators cuts output in half. Again Kenaff’s evidence is that steam generation is significantly affected by lower DNI. (See Trainer 2008 for more detail.)  Very important is the fact that the White Cliffs system involved only 14 rather small dishes and thus a very short distance for heat to be moved to the engine room, and the Big Dish is a single unit close to its steam generator. For the equivalent of a 1000 MW plant very long distances would be involved (or many small power blocks.).  Thus it is not possible with this information to estimate a winter average net output after heat storage, but it would seem likely to be well below 30 W/m.

The heat storage strategy using dishes which looks most viable is that being developed by the ANU group, involving the use of ammonia dissociation as a means of heat storage (Lovegrove et al, 2004).  Perhaps its main advantage is that no insulation is required, so heat would not be lost from the storage pipes or tanks.  (The energy is stored chemically, in the splitting of ammonia into hydrogen and nitrogen.)  This system is being built into a commercial plant at Wyhalla, South Australia.   It is estimated that half the energy entering the dish might be available for generating after storage by this means. (Wizard Power personal communications.)

The designers cannot predict performance confidently at this stage (personal communications), and understandably will not make the technical information they do have available.  It would seem from above that if Big Dish efficiency can be raised to 19% then after storage at 70% efficiency, then can overall efficiency of 1.3.% could be achieved.  Gross winter output in Central Australia then might correspond to the region of 28 W/m continuous 24 hour flow. (At present Big Dish efficiency the figure would be 19.8 W/m/.)

Several factors would reduce this gross figure, including the effect of warm up delays after the passage of cloud, operating energy costs, energy embodied in the construction of the dish and the long trans mission lines (“emergy”), energy losses in those lines, and especially the embodied energy cost of the ammonia processing plant (including the reactors in the dishes which dissociate the ammonia, and the one in the power block that recombines it.).  The emergy implications of the ammonia processing plant are difficult to assess, and could be problematic.  The attempt sketched in Trainer 2008 suggests supply from a 1000 MW plant, taking the most favourable of the estimates for storage volume received (17 litres per kg of ammonia, and 4 MJ/kg), might require some 2,800 km of one metre diameter gas pipe, the intended containment vessel.

Also a concern is the fact that big dishes (Whyalla will use 500 square metre dishes) involve disproportionately higher materials and energy costs for structures, foundations and drive equipment, in view of the higher wind stresses they will have to cope with.  An uncertain estimate based on the materials in the ANU Big Dish indicates an embodied energy cost three times that of troughs, i.e., in the region of 13% of plant lifetime output.  (Trainer 2008.)  However the developers believe other advantages of big dishes outweigh these factors, although I do not know whether this is only a dollar cost calculation or one focused on embodied energy costs.  There is a high probability that in future the cost of materials and construction will be far higher than they are now.

These figures suggest that a solar thermal ammonia storage system will be capable of low but significant/useful net output in winter. From above, net energy delivered to distant users would seem likely to correspond to around 20+ W/m of collection area (not  plant area including space between dishes). However it is not clear that the very large numbers that would be required could be afforded.  On the above estimates a plant capable of delivering 1000 MW in winter might have to include up to 50,000 big dishes each of 400 square metres.  These would probably have to be spread over an 11+km x 11+ km area.   Just to connect the dishes to the power block would probably require some 2,800 km of pipe, although it would not have to be insulated.  This seems to be about the length needed for storage above, but easily overlooked is the need for the same length of pipe to carry the recombined ammonia back to the dishes from the power block. Having many small plants rather than one big 1000 MW plant would not alter the overall ratio of pipe length per kW output.  The total 5,600 km of steel pipe capable of taking 15mPa pressure might weigh 280,000 tonnes and have an embodied energy cost of 11.2 PJ.  This is around 45% of the annual output of a 1000 MW power station (assuming .8 capacity), so the embodied energy cost of the pipe alone might add 2.2% of lifetime output to the total embodied energy cost figure.

Also of concern is the fact that if net delivered output corresponded to a say 25 W/m flow in winter, then it would take 46 metres of dish collection area to sustain one person at the Australian average electricity consumption rate, meaning that the ANU Big Dish would provide for only 8+ people.

Direct hydrogen production.

It is possible to produce hydrogen by splitting water at high temperature, around 800 degrees, and a practical application of solar thermal to this strategy is being discussed. (Taylor, Davenport and T-Raissi, 2008 )  A theoretical 40% solar to hydrogen efficiency is thought to be achievable. If this becomes viable it would probably be the best option, although it would involve the usual problems in large scale handling of hydrogen. These include pipe embrittlement, leaks, and the very low energy density meaning either very large storage volumes and/or high compression. Especially problematic are the energy losses in long distance transport.  Bossell estimates that to pipe hydrogen from North Africa to Western Europe could require more than half the energy despatched from Africa. Ideal solar thermal sites are a long way from demand.

A system designed to deliver 1000 MW after storage would need a 1000 MW hydrogen-fuelled power station in addition to the dish system which generated the 1000 MW supply of hydrogen to run it, indicating high capital and embodied costs.  The efficiencies of the various steps (e.g., .4 for hydrogen production, .8 for handling/transport, .4 for fuel cell generation) suggest an overall gross solar to wheels/use efficiency of 13%, from which the embodied and operating costs of materials-expensive hydrogen handling plant would have to be deducted.  It is therefore not clear that this path would be more viable than the others considered above.

The intermittency problem.

The heat storage capacity of solar thermal systems overcomes some of the intermittency problems that trouble wind and PV systems, such as the occurrence of night time.  The standard provision will be 12 hour storage enabling continuous 24 hour electricity delivery.  However examination of climate data reveals that even at the best sites sequences of 4 or more days without sunshine are not unusual.  The best US sites often have 2 runs of 4 consecutive days of cloud in a winter month. (Davenport, 2008)

If 1000 MW(e) output was to be provided for four cloudy day from stored heat, some 290,000MWh of heat would have to be stored. Storage cost has been estimated at $(A)10/kWh(th) meaning that the required storage plant would cost more than $8 billion, or around twice the cost of a coal-fired plant plus fuel.  However this refers to trough technology and it is likely that for the ammonia process costs would be higher.

Again we would be faced with the prospect of very high capital costs for a large amount of plant that would not be used most of the time, and would still be insufficient occasionally.  There would also be the question of whether there would be enough solar radiation in winter to meet daily demand and also recharge a large storage sufficiently to cope with the next run off 4 cloudy days.

The climate evidence given in Trainer 2008 seems to show that solar thermal systems even at the best locations would suffer a significant intermittency problem, despite their capacity to store energy.

Another problem is that if solar thermal plants are to help buffer the intermittency of inputs from other renewable sources then a major cost saving often claimed for solar thermal systems would not be available.  The ability to store heat from peak mid day collection and generate with it at a much lower constant rate, perhaps .2 of peak capacity, means that much smaller and cheaper generators can be used, perhaps one fifth of the capacity that would be needed to use heat energy at the mid day rate of collection. The power block can make up around half of a solar thermal system’s cost so the saving in capital costs, energy costs and operations and management is considerable.  However if the solar thermal component of a renewable supply system must at times plug gaps left by variable wind and sun, then there will be times when it must meet almost all demand and so its individual stations must often be cable of generating at much greater than average rate.

There would also be a problem regarding the need for solar thermal plant to rapidly ramp up to high levels of output, in order to meet most of the demand when sun and wind energies fall suddenly.  Thermal generators can’t be brought up to full output quickly.

It is sometimes assumed that solar thermal systems will enable the gaps left b y other renewable sources to be smoothed out, by use of solar thermal heat storage capacity.    For this to be plausible storage capacity would have to be extremely large.  The following figures seem to show that this proposal is not viable.

If the solar thermal system was to average .3 of total electricity supply yet  had the storage capacity to meet total electricity demand through 4 calm and cloudy days, then its storage capacity would have to be 24 times as great as for 12 hour storage.  In addition its collecting capacity would have to be considerably greater then that required for average output, in order to accumulate such a reserve.

This evidence seems to mean that there is no chance that the capacity of solar thermal systems to store energy could overcome the problem of gaps left by combining the output from the other renewable energy sources, as some have hoped.

Solar thermal conclusions?

The climate data seems to show that despite their storage capacity solar thermal systems would suffer a significant intermittency problem and in winter would either need storage capacity for four or more cloudy day sequences once or twice each winter month, or would need back up from some other sources.  This means they could not be expected to buffer the intermittency of other components in a fully renewable system.

It seems that troughs suffer a big drop in output in winter, that dish-steam systems cannot operate well enough on stored heat and that hydrogen generating systems are too handicapped by the usual difficulties associated with hydrogen.  The prospects for satisfactory winter supply of electricity from solar thermal systems therefore seem to depend on whether or not the dish-ammonia system will be viable on a large scale, and capable of overcoming intermittency problems.  The unsatisfactory information available suggests that they will be significant contributors but are not likely to make possible reliable winter electricty supply at a tolerable cost, that they will suffer a significant intermittency problem, and that they cannot be a solution to the integration problems left by other renewables.

The dumping and additivity problems (for technosolar in general)

Discussions of renewable energy contributions to total demand also typically give little or no attention to the problem of energy dumping set by the variability of renewables. This increases the need for energy conversion and lowers average capacity factors. Consider a system in which over time wind and PV each supply one-third of demand (i.e., .33 x total demand). The world average wind farm capacity is .23, which means that at times output from a farm will approach 4.3 times average output. For PV systems in good locations annual average capacity is probably about .18, meaning that on a sunny day a system will be producing about 5.6 times average output. Now consider a system in which wind and PV components each contribute on average .33 of total demand. On a sunny day which is also quite windy these two components might be producing about 3.3 x (total demand). So even if the non-renewable components in the system can be shut down, 2.3 times as much energy as is needed would have to be dumped, or stored inefficiently as hydrogen. This would have a dramatic effect on the system’s average capacity measured in terms of energy actually used. (Storing as hydrogen and regenerating via fuel cells might yield no net electrical energy when system operating and embodied energy costs are deducted from the perhaps 25% of energy available after conversion, storage and retrieval.)

Stern’s Fig. 9.4 shows that this dumping problem has not been taken into account. Total demand is divided into components reflecting averaged or annual contributions with no consideration of what would happen when some or all are performing at their peak capacity rather than at average capacity.

The variability between summer and winter would more or less double the magnitude of this problem for solar sources, given that in good solar regions winter insolation is about half the summer value. (The multiple is greater in the lower latitudes.) Thus a PV system designed to meet 30% of demand in winter might meet 60% of it in summer. The effect would be offset to some extent by the fact that winds tend to be higher in winter. However with daily variability the effects compound rather than compensate; i.e., at night when there is no solar input winds tend to be lower.

Renewables are not additive

Renewable energy sources are usually thought of as additive, that is, as if building X GW of wind capacity and X GW of PV capacity would give us 2X GW of generating capacity. However on calm nights these two sources would give us no generating capacity at all. Thus they are best thought of as sources which at times can be alternated with or substituted for coal fired power, but not as sources which can always be added to each other. (Stern’s Fig. 9.4 reveals that the various components are being thought of as additive.) This means that we might have three or more very expensive systems each capable of more or less meeting demand while the others sit idle, and in addition we must retain a coal or nuclear system capable of meeting most or all demand when most or all the renewables are down.

——————————————————–

Questions that arise: (from a recent email to me by Ted)

1. How viable is storing heat from dishes? My European contact says not worth it. There would be long distance piping from tens of thousands of big dishes for a 1000MW power station, and thus large heat loss. With troughs heat moves through heated absorbers most of the way.

2. Where can we get performance data, for the different ST types, for every day of the year, along with solar radiation data for the sites in question?

3. What is the embodied energy cost of the ST types; Lenzen and Dey say 4% for troughs, but my attempts to check this are unsatisfactory, and it seems that for dishes the cost would be much higher (Derived from big dish materials inventory.)

4. Analysis is required of climate data for Eastern Sahara, SW US, and Central Australia, especially actual daily pattern of radiation (ideally pattern of hourly radiation every day.)

Another issue that require resolution concerns the angle between sun and reflector (the ‘cos‘ problem). With dishes this is no problem ever because you can point them at the sun anytime, so  I have tried (in the above) to deal with dishes mainly, because if that’s problematic then towers and troughs are out…because they do have an intractable cos problem, especially severe in winter even in the best regions. Troughs it seems just can’t do it, as performance goes down to 20%- of summer output in winter in the US good sites. Towers (CR) are of course good for storage, but I’m assuming their cos problem is serious. It would be great to get some actual data on their year round performance. I have found it fiendishly difficult to get such data out of anyone; they seem not to want to make it public, and this makes evaluation of claims very difficult.

Another problem is that if heat loss is 1% over a 12 hr period, which is what Sargent and Lundy seem to say, then over a 4 day period this is 8%, so would have to be added to other factors detracting from overall ER and dollar cost situation. BOM is where to go for climate data (in Australia) and I have put some time into this. I could get more detailed information than I have but what I have indicates that there is a problem with sequences of cloudy days in winter, even in Central Australia. US seems much worse. Can’t get much confident data on North Africa, which is what ST electricity for Europe would depend on. Note a problem is time taken for systems to come back up to output after “transients”; i.e., passage of cloud. Can be significant I believe, and thus average radiation per day could be misleading; if this is made up of a lot of passing cloud and sun you might not total much time on full output.

——————————————————–

If anyone can help Ted source relevant information on the above (or if you have insider information, email him), I’m sure he’d greatly appreciate it.

Classifying ‘belief systems’ in sustainable energy and climate change

Below I reproduce a fascinating analysis, which attempts to classify people’s ‘belief systems’ in sustainable energy and climate change into four broad categories, types A, B, C, and D. (Note that this is only an excerpt from the introduction of a larger report that Gene is currently writing)

It is written by Dr Eugene Preston, who is a highly-experienced energy transmission systems consultant and member of IEEE. He also teaches classes at the University of Texas. Gene and I correspond regularly as participants of a sustainable energy email group (this particular group is rather special, in that it has a focus on a certain type of technology — no prizes for guessing which one). I reproduce the analysis below with Gene’s permission, and I hope he’ll be able to join in with the opinionated discussion that is likely to follow.

Each person has a belief system that strongly drives them to some vision of what our future should be. Gene says he’s type C (so am I). Which one are you? Is he missing any types of beliefs? How much overlap is there between the categories?

———————————————–

Belief Classifications

Eugene Preston (http://egpreston.com)

There are many ideas floating around today about how we should develop our future energy supply. People’s opinions are strongly shaped by what they believe to be true. Here is one example of the beliefs that shape the opinions of how our energy future should be developed.

———————————————–

A. Belief: Nuclear proliferation is a greater concern than climate change.

1. The world’s greatest risk is from nuclear weapons, most likely from terrorists or a rogue nation. Nuclear power should not be expanded until non-proliferation of nuclear materials can be assured on a worldwide basis.

2. Climate change is a problem we must begin to deal with, although its severe effects will not be felt until later, possibly at the end of this century.

3. Coal is a plentiful energy supply the US does not have the luxury to ignore. Capture and storage of CO2 is a technical problem that must surely have a solution.

4. Oil imports must be significantly reduced because the US cannot sustain the outflow of dollars from the US to other countries. Worldwide oil production has not yet peaked.

5. New technology will emerge in battery storage and solar cell manufacture, which will make electric cars and roof top solar power economical and solve the above #4 problem.

Do you recognize these opinions are those of President Obama? The current US energy policies are strongly shaped by these beliefs. Some of these beliefs may be true and are likely to happen, some are too expensive to implement, and some will not be technologically realized. Note that at this point I didn’t say which ones will succeed and which ones will fail. You will be able to see which ones by the end of this report. A well-engineered system can handle the uncertainties and risks. However, I can say for certain, that the above beliefs do not adequately address all the things that we need to be addressing, to insure a safe, reliable, clean, and economical power and energy supply for both electricity and transportation, as well as address the environmental cleanup challenge and also provide new energies for things such as space exploration and additional clean water supplies for the future.

A slight change in beliefs will cause a huge shift in what you think the US energy policy should be. Here are the same bullet items from a person who is completely anti-nuclear.

B. Belief: Solar-wind-conservation and no nuclear is the solution to our energy needs.

1. The world’s greatest risk is from all forms of nuclear which should be completely banned.

2. Climate change is a severe problem and can be dealt with by switching to solar, wind, bio energy, battery storage, and a greater use of conservation.

3. Coal plants should be banned because they emit CO2, which is bad for the planet.

4. Oil imports will be eliminated when all transportation is electrified, or switches to natural gas, which the US has plentiful supplies of. Worldwide oil has probably peaked.

5. Solar cell costs are dropping, new battery technologies will soon be available, and all the renewable power sources make the non-renewable forms of power unnecessary.

This group differs from the A group in that coal and nuclear power are included in the A group but not in the B group, which are opposed to coal and nuclear power. I know many people who fall into the 100% solar-wind-conservation category. The current CEO of Austin Energy and some of my personal friends are type B persons. I think that most persons in the Sierra Club and the Repower America group as well as followers of Al Gore are mostly type B believers. The type B plan will be examined in this report as an engineering exercise at these three different levels: 1) the individual homeowner, 2) an electric utility, and 3) the entire US.

Now I will give you the beliefs of persons who are extremely concerned about the climate change problem. These are concerned scientists who are driven by a rather scary vision of the future.

C. Belief: Climate change is the Earth’s greatest threat which can lead to extinction.

1. The world’s greatest risk is not nuclear weapons or nuclear power because those problems will pale in comparison to the climate change problem. Nuclear power is the only power source that can supply enough power to reverse the climate changes. Using IFR technology, the US has a several hundred year supply of fuel already on hand in the form of high level nuclear waste, which the IFR plants can use as its primary fuel. To make a complete switch off fossil fuels in the US might require 400 new IFR plants.

2. Climate change is the worst nightmare ever encountered by humans and might lead to extinction of all life on the planet once thermal positive feedback mechanisms kick in.

3. Coal plants must be completely retired as well as all sources of CO2 emission (such as petrol cars). Possibly removal of CO2 from the atmosphere will be necessary to allow the oceans to become less acidic, which is currently causing a destruction of life in the oceans. CO2 sequestration is not going to be widely applicable because of the potential environmental damage as well as the implementation costs needed to capture the CO2.

4. Oil imports will not be a problem because there will be minimal use of fossil fuels.

5. Solar power, wind, and batteries may or may not develop, and it doesn’t matter whether they do or do not, because if they don’t, we can rely on nuclear power for all our needs.

The above beliefs are those of Dr James Hansen and an increasing number of scientists. US policy will slowly move toward C if the IPCC reports increasingly support these scientist’s predictions and neither the energy ideas in A or B prove to be complete climate change solutions.

There is one other group that I need to state because they represented the ideas of the previous administration and are still strongly supported by many persons in the US, especially the Senate.

D. Belief: Climate change caused by humans is fiction.

1. Nuclear power is an economical source of power and eventually a way will be found to handle the nuclear waste problem. Nuclear weapons proliferation is adequately addressed here in the US. Rogue countries and terrorists can be dealt with through international agencies, treaties, and rules. Additional nuclear power in the US should be dictated by the economics of the free market, not a socialized system such as the French nuclear program, i.e. the US government needs to stay out of the nuclear power building business.

2. Climate change caused by humans is fiction. The CO2 amounts are far too small to cause the claimed warming. We may be in a cooling trend. A new ice age is likely to form at any time. Climate change hysteria is causing us to make bad investments.

3. Coal power is the cheapest on the planet and should be developed to meet our energy needs, including energy for transportation, to ease the nation’s oil import problem. CO2 capture costs and cap and trade program will harm the US economy and are unnecessary.

4. Oil imports will be addressed by developing new oil supplies in the Gulf, off the east and west coasts, in Alaska, in the Arctic, and from Canada’s oil and tar sands. In total there is plenty of oil to continue our current lifestyles for decades. All we have to do is go get it.

5. Solar and wind power will make some advances, although they will supply only a small amount of energy compared to gas, coal, and nuclear power supplies already operating. The energy problem is solved for now by conventional methods. There are likely to be new energy solutions in the future that can be implemented when they are needed.

These beliefs are strongly held by many persons in the electric power industry. The US Senate report strongly supports the above ideas. Many of the persons living in my neighborhood are type D believers. I have many ham radio friends who are type D believers.

However, the entire set of beliefs in D crumbles if: 1) the earth continues to warm and certain things like the melting of Greenland’s ice continues at an annual accelerated rate, 2) the acidification of the oceans continues to increase, 3) IPCC reports increasingly show the effect humans are having on the planet, and most importantly, 4) the oceans begin rising more rapidly and at a predictable rate. I will examine the possibility of an accelerating rate of Greenland’s ice in this report and then you can make the call as to whether you want to continue to support the beliefs listed above (assuming you are currently a type D believer).

———————————————–

There are odd relationships in the above sets of beliefs. For example, those strongly believing in climate change (C) and strongly against climate change (D) both believe in developing more nuclear power, but for different reasons. However, their ideas diverge on the use of coal.

Climate change drives those opposed to nuclear power (A and B) into believing that wind and solar power will make a significant difference, however, the strongly anti nuclear and anti coal (B) split with the moderates (A) on the future need to have coal and nuclear power.

———————————————–

Endnote:

How effective will the cap and trade be at eliminating coal plants? I recently attended the Bureau of Economic Geology seminar at the University of Texas. A handout (that was in a handbag labeled as Clean Coal Technology Information by American Electric Power) stated that cap and trade in Europe had seen market values of 30 $/ton of CO2. A 1000 MW coal plant will produce about 3 million lbs per hour of CO2.

I verified that this rate of CO2 production is correct when one of my friends said it couldn’t possibly be that much. It is a good average taking all coal plants into account, new and old, small and large. Newer plants might have slightly less CO2 production. You also have to be careful about some CCS reports that show smaller amounts of CO2 capture. The are probably capturing only a part of their CO2 emissions.

Multiplying (30$/ton)(3e6lbs/h)/(2000lbs/ton) = 45000 $/hr …. then

($45000)/(1000MWh) = 45 $/MWh = 4.5 cents/kWh, which is a very high cost, higher than the bus bar cost of a new coal plant.

The cap and trade will show that coal is not the lowest cost base load generation. Nuclear will win that battle. However, power companies move slowly. It will take several decades for existing coal plants to be retired and new nuclear plants to be constructed if we follow the traditional utility planning practices. I do not think this will work if the type C beliefs are correct. Because there are many different beliefs, the IFR will develop slowly unless we can eliminate the beliefs of the categories A, B and D by showing they are in error and will ultimately lead to failure.

Power to the People – Nuclear energy in South Australia

Update: Listen to me on ABC Radio, talking about nuclear power, fast breeder reactors, renewables, and the inevitability of growing societal energy demand. This also features an interview with Dr Jim Green, and my response. It runs for about 16 minutes in total: http://tr.im/vXE2

—————–

Published in the Adelaide Advertiser, 4 August 2009 (pg 18). This opinion editorial I wrote builds on the recent flurry of interest in the Australian media on introducing nuclear power.

BARRY BROOK IN MY VIEW

Imagine someone handed you a lump of silvery metal the size of a golf ball. They said you might wish to put on some plastic gloves to hold it, although that would not be necessary if you washed your hands afterwards.

You look down at the metal resting on your palm. It feels heavy, because it’s very dense.

You are then told that this metal golf ball can provide all the energy you will ever use in your life. That includes running your lights, computer, air conditioner, TV, electric car, synthetic jet fuel.

Everything. Using 1 kilogram of uranium (or thorium, take your pick).

That is what modern nuclear power offers. An incredibly concentrated source of energy, producing a tiny amount of waste.

Taken over its life cycle, when used in next-generation fast spectrum nuclear reactors, this energy generation will produce less carbon dioxide emissions than wind turbines. It gets better.

Your lifetime’s worth of energy waste, also weighing just under a kilogram, will be less radioactive than the natural rocks around Roxby Downs within 300 years. Not 100,000 years. Only 300 years.

South Australian rocks contain this metal in great abundance. We live in one of the most energy rich areas on the planet.

We are endowed with far more energy than all the oil and gas in the Middle East. We already export a few thousand tonnes of it each year, and are planning to ship much more overseas in the future. Yet, we don’t use it ourselves.

We recognise the fact that our natural gas supplies are limited. Worse, burning this fuel produces vast amounts of carbon dioxide, which is destabilising the climate system.

Coal, found in great abundance in Australia’s east coast states, is twice as bad as natural gas in terms of carbon emissions, and also dumps heavy metals, soot and chemicals causing acid rain into the air. Clearly, we must unhitch ourselves from the fossil fuel energy bandwagon, and quickly.

Right now, we are pushing for more and more wind and solar power. This is well and good, but these variable and diffuse renewable energy sources have severe limits that often go unacknowledged.

They cannot power a large fraction of the needs of future all-electric society without major breakthroughs in energy storage technology, and much cheaper backup options than now exist.

Energy found in hot rocks deep beneath our deserts holds great promise, but is shadowed by many unknowns. We’d be taking a great risk if we gambled our entire energy future on this one possibility.

My research has convinced me that nuclear power is by far the best prospect that we, as South Australians and as a global community, have of drastically cutting carbon emissions.

The world is experiencing a nuclear renaissance, with almost 50 new reactors now being built, and another 350 being planned, in places like China, India, Europe and North America.

Nuclear power station companies are now focusing on designing smaller sized reactors that are built to a standardised, ultra safe design, in a factory, and then shipped to site. This brings economies of scale to bear, which means cheaper electricity.

Also, because each individual reactor can be quite small, you can simply add more units as your energy needs grow, and as your retire old infrastructure. The age of huge plants, which can be difficult to finance and take many years to build, may soon be history.

It’s time for Australia to embrace nuclear power as a major enabler of a low carbon economy. Companies like Rio Tinto recognise this need. We all should.

After all, South Australia is perfectly positioned to be a leader in this new energy revolution.

Barry Brook is Sir Hubert Wilkins professor climate change at the University of Adelaide’s Environment Institute.

INSET BOX

Almost 90 per cent of the world’s — and Australia’s — electricity is powered by fossil fuels.

Despite conservation efforts, global demand for electricity is growing at about 2 per cent a year.

Australia’s use of electricity is expected to double from current levels in the next 30 to 40 years.

About 36 countries use nuclear power, which accounts for almost a quarter of electricity generated in OECD countries.

In France, 80 per cent of electricity is nuclear.