Key concepts for reliable, small-scale low-carbon energy grids

Recently, I published a guest post by Gene Preston which examined the electricity cost comparison for remote solar PV vs small nuclear reactors. This generated considerable discussion (128 comments), much of which focused on whether this was a useful comparison in many circumstances; what if, for various reasons, the small-scale nuclear battery is not a viable option?

Gene has since done further work to consider the problem of how to design a reliable, small-scale, low-carbon energy generation system, which is economically competitive (though not necessarily lowest cost). He uses a case study approach to consider five crucial aspects:

1. System 1: A rooftop solar and wind 100% renewables powered microgrid concept.

2. System 2: Like (1), but the 10 kW rooftop solar is replaced with 5 kW of centralized solar.

3. Analysis 1: Three ways to improve the reliability of a (nearly) 100% renewables system.

4. Analysis 2: The cost of CCS carbon capture and sequestration makes coal power uneconomical.

5. Analysis 3: Small nuclear power provides reliability without needing a new transmission grid.

First, here is a summary of the five cases. Following this overview, the case studies are given in full (for the more dedicated reader). I find these type of empirical studies incredibly useful in understanding the options available to us. Great work Gene.

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In all the cases the microgrid has 150 homes. This number of houses was selected to best match the output of a 1.5 MW wind generator. Of course the size of the system could be scaled to any number of houses. The intent is to design each system to be as independent of the larger grid as possible. Each house has two PHEVs with 50 kWh batteries for a range of 100 miles of city driving for each fully charged vehicle. Each home is assumed to annually use about 12500 kWh plus another 12500 kWh for the PHEVs for a total of 25000 kWh per home annually. The PHEVs are assumed to be bi-directional power sources, being able to both receive power from the microgrid and deliver power to the microgrid in all cases. The microgrid consists of an undergound distribution system connecting the houses as well as the power sources local to the microgrid. All the costs for the distribution system, metering, etc that are the same for each of the above cases are not included in these calculations. The purpose of this analysis is to simply compare the cost and reliability of different types of power sources.

Here are the findings:

Case 1 has 10 kW of rooftop solar fixed panels at each house and a 1.5 MW wind generator for the whole neighborhood. The up front cost of the solar and wind per household is $90,000. This system will suffer occasional power deficiencies if operated as a standalone system. The interconnection costs for backup power from a larger grid were not estimated.

Case 2 replaces the rooftop solar panels with a centralized tracking solar system of size 750 kW.This saves each homeowner about $45,000 in up front costs and raises the question –- why are we installing rooftop solar when the centralized solar system is so much more cost effective? This system suffers the same problem as case 1 in that there will be occasional power deficiencies.

Case 3 looks at three ways to improve the reliability. #1 adds more battery storage and more renewable capacity to charge up those batteries and costs $100,000 more per household. However, this is still not a completely reliable system. #2 connects all microgrids in the US together with a massive investment in new transmission lines to gain reliability. The cost and environmental impacts are found to be impractical and the time to get approval and construct all the lines could take many years. #3 looks at installing backup generation at the microgrid instead of interconnecting. This is equivalent to firing up a put-put generator when solar andwind fail to produce enough power. The types of fuels discussed are oil, gas, coal, and nuclear. All of them are reliable, except they are deviations from our desire to be dependent only on 100% renewable power.

Case 4 looks at the cost of CCS carbon capture and sequestration and finds that it adds about 16 cents per kWh to the cost of coal generation, making coal unattractive as a base loaded source of power. Case 4 also shows that a 1 MW coal plant beside our subdivision eliminates the need forany solar or wind power at all and it would be the lowest cost if not for the CCS cost. With CCS coal looks no more economical than our 100% renewable plans, although the 100% coal is quitea bit more reliable than the 100% renewable plan, because the coal generator can run 24/7.

Case 5 looks at adding a small 300 kW nuclear plant beside the subdivision. It is air cooled and fits in a single homeowner lot. It silently runs for 30 years on a single fuel load and requires little maintenance. The wind generator is eliminated and the central solar is retained. Thesystem is reliable. The PHEV batteries are lightly used, allowing them to last longer. No new transmission lines are needed. This plan has a $45,000 up front cost to each homeowner.

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Designing a Rooftop Solar + Wind + PHEV 100% Renewables Microgrid.

Let’s consider a 100% renewables microgrid power system consisting of:

1) a single 1.5 MW wind generator located near a residential subdivision,

2) 10 kW of solar fixed rooftop panels on each home,

3) two PHEVs at each home with 50 kWh battery storage in each PHEV,

4) each home will use 25,000 kWh annually for electrical home use + transportation.

The wind generator costs about $2/watt or $3 million. The wind generator will be able to supply about 4000 MWh annually if the capacity factor is about 30%, which is typical. This microgrid might be able to operate independently from the larger grid if their location has enough wind and sunshine, such as Midland, Texas. Most customers will need to get their wind power from remote and windy locations that can produce energy at the lowest $/kWh cost.

The rooftop solar panels cost $7/watt or $70,000 per house and produce an amount of energy of (10 kW)(.77 DC-AC converter eff)(.15 annual capacity factor)(8760 hours/yr) = about 10,000kWh. The .77 is my EE friend’s new 4.4 kW system which produces 3.4 kW AC power.

The remainder of the energy must come from the wind generator, which is 15,000 kWh per home. In order to have some reserve, we should double the wind available energy as a part of the microgrid interconnection in which our renewables must also serve others so that we can draw power from other microgrids. Therefore, for estimating how many homes the 1.5 MW wind generator can serve, let’s be conservative and assume that each home will need 30,000kWh wind (double the 15,000). This means that our microgrid can serve a total of 4,000,000 kWh wind/30,000 kWh per home = 133 homes. Let’s round it off to 150 homes. The wind generator cost per home is therefore $3,000,000/150 = $20,000 which seems reasonable.

Each home will have two PHEVs in which most of the time one PHEV is active in driving locally and the other one remains parked in the garage most of the time. Each PHEV contains a50 kWh battery, which has a range of about 100 miles for city driving. Each PHEV charges at 220 or 240 VAC with a 10 kW load or 45 amps and can get a full charge in less than 5 hours andare charging when possible. These EVs are likely to cost about $40,000 each because of thelarge battery storage capacity and the battery cost of $10,000 for the electronics plus(0.4)(50,000) for the batteries = $30,000 total and then another $10,000 for the rest of the car.

The PHEVs are critical to storing energy for times when there is no wind and no solar, especially for an independent standalone microgrid system. The homeowner will need to be aware at all times of the charge state of the batteries and plan their daily activities around the power that is available from their batteries, their microgrid, and what’s available from the larger grid (if any).

The total homeowner cost of this system is $70k solar + $20k wind = $90,000 which should be affordable to most homeowners. The annual cost financed at 6% annual interest rate for 25 years is A = (90)(.06)(1.06^25)/(1.06^25-1) = $7040. The levelized energy cost is 704000 cents/yr /25000 kWh = 28 cents per kWh just for the wind and solar renewable power investment cost.

The 1500 MW wind generator is sized appropriately to simultaneously charge 150 PHEVs. Thesolar panel at each house is also sized appropriately to charge one PHEV at the house. A PHEVcould supply 1 kW power for up to 50 hours for backup power when there is no solar or wind.

Rooftop Solar Versus Centralized Utility Operated Solar

In the previous example, I had estimated that each home would need 10 kW of solar panels at an installed price of $7/watt and an annual capacity factor of 15%. The rooftop solar panels cost$70,000 per house and produces (10 kW)(.77 DC-AC converter eff)(.15 annual capacity factor)(8760 hours/yr) = about 10,000 kWh annually.

If we wanted to invest in utility-owned centralized solar and obtain the same amount of energy asour rooftop solar, how much would we need to spend?

The centralized solar cost is estimated to be $5/watt and have a 25% annual capacity factor. If 10 kW produces (10 kW)(.95 eff)(.25 annual CF)(8760 hr/yr) = 20000 kWh annually, we see that the centralized system produces twice as much energy as the roof top system. Therefore let usrequire only half the capacity or 5 kW per household to get 10,000 kWh annually for that home.

The cost per household is now (5000 watts)($5/watt) = $25000 versus $70000, which is a $45,000 savings per household. So why are we so interested in rooftop solar?

Three Ways to Improve the Reliability of a 100% Renewables System.

In the previous two case studies I used the batteries in PHEVs as the source of backup power when wind and solar power is not available, such as during a calm night. Windless nights will occur frequently. If we have too many windless nights and cloudy days in a row, our 150 homes willbe in trouble because the PHEV batteries will become run down and the lights will go out. And because the batteries are discharged, there will be no transportation either.

You might naively think that a simple connection to the larger grid will solve the problem. It won’t. I will discuss why below. Keep in mind Hawaii, which cannot connect to a larger grid.

#1 – The first possibility for improving the reliability of our 150 home microgrid would be to install more batteries. This will be an expensive addition because batteries are expensive. Doubling the size of the batteries in the PHEVs would cost another $60,000. To keep themcharged up will require increasing the size of solar and wind sources, possibly doubling them,which would cost each home owner another $20,000 for the second wind generator and $25,000 for doubling the size of the centralized solar farm (which is adjacent to the 150 home subdivision). We have spent an additional $100,000 to keep the lights on during extended calmand cloudy days. Our 150 home subdivision residents decide not to invest in additional solar andwind because the power supply is still not completely reliable, even with the additional battery,wind, and solar power additions. The additional storage idea is a bad idea.

#2 – The 150 homes may decide to connect to a larger system to provide backup power during the extended cloudy and calm days. However, the larger system is made up of thousands of microgrids just like ours, all hoping to draw on the larger grid for backup power, and hopefully not all at the same time. In this 100% renewables system, we have some microgrids that have extra power that can be used to supply energy to other microgrids that are short on energy. Each microgrid will need to install more wind and solar capacity than they need for their own system in order to have reserve power to assist their neighboring microgrid systems.

However, there is a severe shortcoming with this design of thousands of microgrids interconnected with each other. Because weather patterns cover large areas, we are likely to have times when large regions become deficient in power at the same time on cloudy calm days.This means that large transmission lines will be needed to cover the US, much like the interstatehighway system so that reserve power from one large area can be supplied to the other distant deficient area. These lines do not currently exist. They will be expensive and take many years to construct. There will be opposition to this plan due to its environmental impact and cost, so this plan may never be fully realized. Note that this interconnected system is not available toresidents in Hawaii. The building of all these lines connecting the eastern US to the western US to the Texas system (which are all currently isolated) is also a bad idea for improving reliability.

#3 – If the 150 homes microgrid wants a nearly 100% reliable source of backup power and does not want to connect to the larger grid, they could install a conventional generator that would onlybe run at times the renewables power is insufficient. There are four fuel types that could be usedto power the standby generators: a) fuel oil, b) natural gas, c) coal, and d) nuclear. Three emit CO2, except CO2 CCS (carbon capture and sequestration) might be used to capture the CO2. On Hawaii the backup fuel would probably be fuel oil rather than natural gas. The 150 homes might choose either a) or b) to keep initial costs low; however, these are not renewable sources.

The cost of CCS – Carbon Capture and Sequestration – Makes Coal Power Uneconomical.

In the previous example, #3c uses a coal generator to supply backup power to the 100% renewables microgrid system consisting of 150 homes. This would be a small generator of approximate size 150 times 5000 watts per house = 750 kW. Possibly a 1 MW sized coal plant would be a goodsize as a backup system. If the cost were $5/watt, then the cost of that backup system would be$25,000 per household. Because the capital cost of a coal plant is high, using it as a backup system does not make sense. That high a capital cost only makes sense if the coal plant were used as a base loaded generator. Interestingly, if the 1 MW coal plant were to run all the time, the solar and wind systems would not be needed and neither would the PHEV storage, except the battery storage can supply peaking power when the 1 MW generator cannot supply all the power demanded by the 150 homes, which would be rarely. Also, the PHEVs are going to be needed anyway to transition off the burning of oil and gasoline.

Ignoring the cost of coal fuel, the capital cost of the 1 MW base loaded coal would be a levelized annual cost of ($25000/home)(.06)(1.06^25)/(1.06^25-1) = $1956 per home. Then spreading that annual levelized cost over the energy consumed on average is 195600 cents/yr / 25000 kWh= 7.8 cents per kWh. Therefore, the base loaded coal plant supplying all the power is much lower in cost than the 100% wind-solar renewables system power cost, which was 28 cents/kWh.

But there is a problem with this design. The coal plant emits a lot of CO2. That CO2 will needto be captured and stuffed into the ground. Current estimates for CCS are about $100 per tonne (2204 lbs). A 1000 MW coal plant that is base loaded produces about 3 million lbs of CO2 per hour. However the CCS takes away 15% of the energy so that the 1000 MW coal plant is now 850 MW net electrical output. Considering that our coal plant is not 100% base loaded, but runs at an average power level of (150 homes)(25 MWh)/(8760 MWh) = 42.8% or 0.428 MW net electrical output, then our coal plant for the microgrid produces (0.428/850)(3,000,000) = 1511 lbs CO2 per hour on average or 0.6854 tonnes per hour.

The CCS cost is $68.54 per hour. On a cents per kWh basis the CCS adds 6854/(428 kWh) = 16 cents per kWh. Adding the CCS cost/kWh to the original coal plant investment cost/kWh we have coal costing 8+16 = 24 cents per kWh and that does not include the cost of coal fuel itself. Neither does it include the cost to pipe the CO2 to some remote injection point. The energy costof CO2 captured coal is nearly as expensive as our 100% renewables microgrid system. The only advantage of coal is that the power source is more reliable than the 100% renewables system, and that is why we were looking at coal in the first place.

Is there a better source of 24/7 power?

Small Nuclear Power Provides Reliability Without Needing a New Transmission Grid.

In this example, we instead use a nuclear generator to supply continuous power to the 100% renewables microgrid system consisting of 150 homes. This would be a small generator of approximate size 150 times 2000 watts per house = 300 kW that runs all the time. If the cost were $10/watt, then the cost of that backup system would be $20,000 per household. This provides a base load power source of sufficient energy to get past the cloudy calm days. Such a system would provide an annual energy of (300)(8760)/150 = 17000 kWh annually per home ormore than 50% of the annual energy needed. I will assume the nuclear generator actually provided 15,000 kWh annually to each homeowner. The wind generator could be eliminated from the mix of power sources saving the homeowner $20,000 in the cost of the wind turbine. The centralized solar farm could supply peaking power during the daytime and make up for the extra energy annually to get the annual 25,000 kWh annually.

The annual cost of the nuclear plant per homeowner would be (20000)(.06)(1.06^30)/(1.06^30-1)= $1453 annually and produce 15000 kWh. The energy cost is 145300/15000 = 9.7 cents per kWh. Nuclear also has an O&M cost that is about 1.6 cents/kWh bringing the total to about 11.3 cents per kWh for a small nuclear plant that costs 10,000 $/kW.

The cost of the centralized solar farm is $25,000 for 5000 watts per home, and produces 10,000 kWh annually. Its annual cost is (25,000)(.06)(1.06^25)/(1.06^25-1) = $1957 and the energy cost is 195700/10000 = 19.6 cents per kWh. Combining the solar and small nuclear plant costs produces an overall energy cost of (11.3)(15000)/(25000) + (19.6)(10000)/(25000) = 14.6 cents per kWh which is our lowest cost option yet. Note that we still have the PHEVs but the demand put on them to supply night time loads has been eliminated, thus extending the life of the batteries and saving a lot of money in transportation costs.

What about nuclear waste? The latest designs of small nuclear plants plan on using lower grade fuel and even burn what we would normally think of as nuclear waste as the main fuel of these plants. Therefore we create a new market for existing nuclear waste, and instead of throwing it away, we burn it further, getting much more energy out of the existing nuclear fuel, up to 100 times more energy. One example of a small nuclear plant is the Toshiba 4S plant.

There are several advantages of a small nuclear plant:

1) 24/7 reliable power nearly eliminates the need for transmission,

2) 24/7 hour base load operation makes wind power unnecessary,

3) the plant site is a small footprint,

4) the 4S plant is air cooled, not needing water,

5) the 4S plant is fueled once and runs for 30 years continuously,

6) solar and nuclear compliment each other in that nuclear provides base load and solardaytime peaking,

7) PHEVs have a continuous source of power by which to charge their batteries

the liquid sodium does not require a pressurized vessel,

9) there is enough fuel to power these reactors for hundreds of years using IFR technology.

10) once the fuel is spent, the entire reactor assembly is shipped back to the factory for refurbishing and another 30 year run,

11) the design is tamper proof eliminating the ability of terrorists to steal nuclear materials,

12) the design is operator error proof, i.e. the design is inherently meltdown proof.

TCASE 6: Cooling water and thermal power plants

Heat engines require cooling, to turn heat energy into mechanical energy (and then, via a turbine-connected generator, to electrical energy). This is an unavoidable physical principle, and is typically exploited via the Carnot cycle. Usually, this cooling requirement uses water.

Why do I raise this point? Because it seems to be a source of much confusion (innocent and deliberate) amongst the energy illiterate, especially when mounted as an argument against nuclear energy generation (and, implicitly, as a reason for adopting renewable energy). For instance, Friends of the Earth have decried:

Nuclear power plants consume large amounts of water –35-65 million litres daily. Indeed nuclear power is the thirstiest of all energy sources. A December 2006 report by the Commonwealth Department of Parliamentary Services states: “Per megawatt existing nuclear power stations use and consume more water than power stations using other fuel sources. Depending on the cooling technology utilised, the water requirements for a nuclear power station can vary between 20 to 83 per cent more than for other power stations.” Global warming and water shortages are likely to exacerbate problems experienced by the nuclear power industry during heatwaves in recent years. Nuclear power plants in several countries, including France and the US, have had to operate at reduced capacity, or to shut down temporarily, because of reduced water supply or to avoid breaching regulations limiting the heat of expelled water.

So what’s the story? Are water limitations and discharge regulations destined to be a major limiting factor for nuclear power, especially for places that are experiences increasing water shortages, such as Australia? The short answer is no — this is classic FUD. For the longer answer, read on.

All thermal power plants, by definition, make use of heat engines with heat exchangers, and so require cooling (although this need can be reduced in various ways, as explained below). This includes coal-fired, nuclear fission, oil-fired, conventional gas-fired, solar thermal and geothermal power stations. The renewable energy sources that don’t have this cooling requirement are hydropower, wind, wave, tidal and solar photovoltaic power.

Water is used in two ways in thermal power plants: (a) Internal steam cycle: to create steam via the energy source (fossil fuel combustion, fission chain reaction, heat exchange with deep rocks [hot dry rock geothermal] or a heat transfer fluid [concentrating solar power]) and convey it to an electricity-generating turbine, and (b) Cooling cycle: to cool and condense the after-turbine steam (this condensation dramatically decreases the volume of the expanded steam,creating a suction vacuum which draws it through the turbine blades), and then to discharge surplus heat to the environment.

In the internal energy transfer water circuit, only a comparatively tiny amount of water is lost (this is the case for nuclear, coal, conventional [rankine cycle] gas, etc). It’s effectively a water –> steam –> water –> steam –> water etc. closed-loop system. In a pressurised water reactor (see diagram), there are two steam loops, only one which is exposed to the nuclear core. In a boiling water reactor, there is a single internal water circuit. Clearly, this cannot be what worries people, as the water consumption for an internal steam cycle is essentially a once-off affair.

So let’s look at (2), the cooling cycle. The amount of heat discharged to the environment depends principally on the plant’s thermal efficiency. High efficiency is achieved by having a large temperature differential, whether it comes from high internal heat or a low temperature external environment, or both. The thermal efficiency of today’s nuclear power plants are around 35%, whereas hotter coal burners can reach 40% or more. Advanced high temperature gas- or molten-salt-cooled nuclear reactors (AHTR) can reach efficiencies as high as 70%.  Bottom line: higher thermal efficiency = lower water usage. In this context, hot dry rock geothermal, which operates at fairly low outlet temperatures of 150 — 250 °C (compared to 300 — 550°C for nuclear and 850°C for AHTRs), doesn’t look that great.

The options for wet cooling are once-through (direct), or recirculating. Once-through uses water from a large body — the ocean, a big lake, or a high-flow river — to bring in water and then reject roughly the same amount after cooling, which is a few degrees warmer; there is little net loss. To use the recirculating method, water is drawn from some available source (e.g. a river) and then water is sprayed down hyperboloid-shaped cooling towers, which exploit the physics of evaporation, in a natural chimney draft, to cool the water. Using the recirculating method, roughly 2.5 litres of water are lost to evaporation per kWh of electricity generated.  A typical 1 GWe plant operating uses about 75 megalitres per day (25 Olympic-sized swimming pools).

Some countries only use once-through cooling using only sea water (which is in infinite supply) — UK, Sweden, Finland, Japan, Korea, China, etc. Canada uses water from the Great Lakes. In the US and France, coastal plants use sea water and a large number of inland reactors use cooling towers or once-through river/lake sources.

For Australia, this raises an important point. Our coal-fired power stations are clustered in regions such as the Latrobe and Hunter Valleys. Why? Because that way, they’re located right on top of the coal seams. When you have to feed 4 million tonnes of this black rock into a 1 GWe plant each year, it makes a lot of sense to avoid te need to move hundreds of thousands of loaded rail cars across the country, and instead to put your electricity generation plants where the fuel is (if you can — in most of the US, they can’t). The caveat is that you must use the water that can be piped to these locations — fresh water — for recirculating cooling. However, if Australia replaced all of its coal plants with nuclear reactors, it could save all that valuable fresh water. Why? Because their geographical location is unconstrained by the fuel supply, since an utterly trivial 25 tonnes of fuel must be supplied to a light water reactor, or just 1 tonne for a fast spectrum or thorium reactor. As such, all of the nuclear power plants could be built along the coastline and cooled by sea water.

An alternative, for any thermal plant, is dry cooling, whereby heat is transferred directly to the air via high-flow forced drafts (using industrial-sized fans, finned radiator pipes etc.). This is a less efficient method than wet cooling, because the cooling fans consume considerable power and the temperature differential that’s established is necessarily smaller. Yet, it may end up being the only feasible option for large-scale desert-based solar thermal power. The sunny and dry desert is one place where water scarcity really bites. For instance, a German solar developer, Solar Millennium, has reluctantly decided to use a dry-cooling method for their two 250 MWe (peak) CSP plants, after the nearby residents feared their aquifers would be sucked dry by the use of 1.3 billion gallons of cooling water per annum. The inefficiencies created by air cooling will increase the size of the mirror fields required to yield a given amount of power. For some interesting further reading on this proposed solar thermal project (with an ecological impacts slant), see here.

Naturally, if water is a real limitation in a given area that requires electricity, then what’s good for the solar thermal goose is good for the nuclear gander — nuclear power can use air cooling too, if necessary. Or, in most cases, you take the win-win option of saving inland fresh water by closing down coal plants and building your nuclear plants by the sea. I guess Friends of the Earth didn’t think of these points — or, perhaps, they just chose not to mention them. But at least now, having read this TCASE post, you’ll not be tricked by this anti-intellectual sleight-of-hand.

For further information, I can thoroughly recommend that you read this from the WNA: Is the Cooling of Power Plants a Constraint on the Future of Nuclear Power?

Forget the quality, it’s the 700 million tonnes which counts

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.

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There’s a gross cognitive dissonance when a Government who professes to think that climate change is the defining issue of our generation can’t face down a few blustering cowboys. This is implied in the anouncement that agriculture will be omitted from the CPRS.

Well, that’s not quite true. Doing good things like planting trees will be rewarded by allowing farmers to sell pieces of paper called offsets. Doing bad things … like generating more warming than all our coal fired power stations, like causing 6,000 new bowel cancer cases annually, like giving teenagers athlerosclerotic plaques. These will also be rewarded in the usual way … by the traditional head in sand approach on the emissions and by medical subsidies while continuing to allow Meat and Livestock Australia to mislead the public without being bothered by silly inconveniences like truth in advertising laws. This is analogous to the time honoured principle behind handling the Global Financial Crisis, privatise the profits and nationalise the losses.

Recall that it isn’t very much of agriculture which is the problem, it isn’t the potato growers or the wheat millers, or the fruit and vegetable growers. Their emissions are tiny and we have no low emission alternatives to these foods when it comes to eating. Quantitatively, even the downstream food processors and transporters are relatively low in emissions. For new readers let me just spell it out once more … suppose the emissions generated by making pasta were the equivalent of a car using 5 litres per 100 kilometers. What are the emissions generated by lean beef equivalent to? About 1000 liters per 100 kilometers. Would we allow cars that were so inefficient? Obviously our current Government would, at best, merely ask producers of such cars to join the other pigs at the free CPRS permit trough.

So out of the whole of agriculture, the big emitters are just the sheep and cattle boys and there’s not too many sheep boys left after a couple of decades of culling by market forces and cheaper (and sometimes better) fabrics. Like I said in the beginning its really just a few cowboys calling the shots. The interests of these cowboys so dominates the Australian psyche that Kevin Rudd seriously thought a few BBQs would heal the rift over the bashing of Indian students. Apparently neither he nor anybody in his office seemed to understand that asking Indian students home for slashed and seared roast religious icon between 2 slices of limp white bread substitute wasn’t going to be quite the winner on the sub-continent that it is in Australia.

Leading the charge for the cowboys these days is Australian of the Year in 2007, Tim Flannery. He was recently paid by Meat and Livestock Australia to speak at a meat propaganda forum for young students at Roseworthy agricultural college just out from Adelaide. ABC’s Bush Telegraph last week discussed the forum and featured Flannery not only discussing the sustainability of red meat but prophetically outlining exactly what Government policy should be. And so it came to pass, that before the sun rose and set a few more times, the deal was done and announced. Bush Telegraph did a follow-up program the next day featuring a rerun of Flannery’s statements and a response from philosopher and well known animal rights campaigner, Peter Singer.

Questioned about the livestock methane problem, Flannery was broadly dismissive, playing the but it’s natural card with a typical sloppy, unquantified and totally irrelevant truism:

red meat has been part of our diet for a very long time … there’s always been cows and sheep and other large herbivores on land burping and farting … they’ve been part of the natural system

Bush Telegraph played some choice comments at the end of the program from students who attended the forum and these indicated clearly that this truism had made a great impression. Perhaps BT can reinterview the students in 7 years time and see if the famous Jesuit maxim is true. The Australian version would be give me a child until he is seven and I will give you the red necked bigot.

Flannery’s truism probably conjures up images of huge herds of bison covering North America and massive herds of wildebeest blanketting the African continent. For many, wildlife documentaries have made such visions far more common than those of livestock. But this all too easy vivid image fails to capture the quantitative essence of the way livestock now dominate the planet having all but totally eliminated wildlife. It is precisely Flannery’s brilliant inspirational capacity as a speaker and author which makes his fundamentally woolly headed romanticism particularly dangerous.

Wildlife rates of conception, growth, and the like don’t match what can be achieved by artifical selection, artificial insemination, good fences, irrigated feed production, predator extermination and all the other paraphenalia of modern agriculture. These have produced a totally unnatural and unprecedented explosion in numbers of those animals which people have designated as livestock.

Consider the following table. The left side is from a 1994 paper estimating methane flows in the year 1500. It pulls together historical and ecological estimates of populations of relevant species and also gives an estimate of the human population of about 466 million. Rather less than the current 6.7 billion.

As you can see the estimates for wildebeest and bison in 1500 are dwarfed by modern populations of cattle, sheep, pigs, goats and even buffalo (mainly water buffalo).

The livestock population estimate on the right side of the table comes from a 2008 paper also looking at methane flows but which doesn’t deal with wildlife species. Where we have estimates on both sides of the table for a species the differences are stark. Run the numbers and you’ll see, for example, that the ratio of cattle to people has almost doubled. But despite this growth and the destruction of huge swathes of forest on most continents, beef provides just 1.3% of global food calories.

What the right side population numbers don’t show is the dramatic increase in the size and growth rates of some species. For example, while cattle outnumber pigs in the table, pigs provide 3 times more food calories than cattle … which is still not much food all of it causes bowel cancer. The pig industry output is due to huge increases in growth rates, with appalling consequences for breeding sows.

With cattle, the size increase has been dramatic. Indian cattle have a carcase weight averaging 100 kg, probably not too dissimilar to cattle in 1500, but the carcases of the feedlot monsters in many parts of the world tip the scales at 350 kilograms.

Chickens don’t appear in the table, they are insectivores rather than herbivores and the planet at any time has about 18 billion with most being now raised in factory farms regardless of whether it is in the developed or developing world. So, while it is true that there have always been herbivores, current livestock populations are unprecedented and these populations include insectivores like chickens and omnivores like pigs.

The total global livestock body weight combines the impacts of increased numbers with increasing sizes. Livestock’s Long Shadow gives a figure of about 700 million tonnes for the global livestock weight. What is the total weight of humans? About 330 million tonnes. Planet earth is clearly not the planet of the apes.

What is the impact of 700 million tonnes of livestock? Apart from a displacement of wildlife, a new WorldWatch report put the total impact of livestock on greenhouse gas emissions at about 51% of our global total. Can the feeding, fodder growth, irrigation for the fodder growth, fertiliser, watering, transport, slaughter, refrigeration, cooking of 700 million tonnes of livestock really be half the global total of our greenhouse gas impact on the climate? I’d say the biomass estimates alone make this plausible. Certainly the livestock of the rich outconsume and out travel many of the world’s poor. While I think it’s too early to judge the robustness of the WorldWatch number, I expect it will eventually be judged reasonably close to the mark.

But in Australia, the red necks are firmly entrenched and even our 2007 Australian of the Year puts BBQ protection ahead of saving the planet and gets paid for it.

Two years, three record heat waves in southeastern Australia

Summer 2009 — 2010 hasn’t even begun in Australia, and yet we are already sweltering under another record heat wave — the third in two years. Temperature records for the month of November have been broken across the region, caused by a blocking high pressure system over the Tasman Sea. This follows an abnormally hot winter, including Australia’s hottest August on record.

In my home city of Adelaide, we’re still experiencing the first official November heat wave since records began (a ‘heat wave’ being defined here as five or more consecutive days above 35°C). Last Saturday 7th Nov, the mercury climbed to 34.4°C, and on Sunday the heat wave officially commenced. From Sun 8/11 to Sat 14/11, the maximum temperatures have been 36.7°C, 37.0°C, 38.6°C, 39.2°C, 39.0°C, 38.7°C  and 39.5°C. The forecast for Sun 15/11 is 40 °C, after which the temperatures will drop back to the high 20s for a few days, and then another burst of days in the low-40s. If Sunday’s scorcher is realised (confirmed: 39.4°C), the heat wave will have lasted for 8 days [confirmed] (almost 9, with Sat 7/11 also almost reaching the threshold 35°C). Not a great time to hold a Christmas pageant — poor Santa!

Time for some context. The closest Adelaide has ever come to a spring heat wave was 4 days in a row 1894. This month’s event will double that — a doubling like this is not twice as unlikely, it’s orders of magnitude more unlikely. Consider that in prior to 2008, the record length for an Adelaide heat wave in any month was 8 days (all occurring in summer). Now, in the space of less than 2 years, we’ve had a 15 day event in Mar 2008 (a 1 in 3000 year event), a 9 day sequence in Jan/Feb 2009 (which included 8 days above 40°C and 13 consecutive days above 33°C), and now, another 8 day event in Nov 2009. How unusual is this? There have been 6 previous heat waves that lasted 8 days, many more of 7 days, more still of 6, and so on — the return time is logarithmically related to it’s length. Given these data, and the fact that the latest spring event has equaled previous all-time summer records (!), and the alarm bells should rightly be ringing. Statistically speaking, it’s astronomically unlikely that such a sequence of rare heat waves would occur by chance, if the climate wasn’t warming. But of course, it is.

The November 2009 heat wave has not been restricted to Adelaide — it’s affecting most of southeastern Australia. Here’s a useful report from NSW (ABC Sydney) by Graham Creed, which noted:

Adelaide’s run of record November heat has been in the media spotlight for much of the week but there have been longer runs of heat. Batchelor, a mining town 100km south of Darwin with a permanent population under 400, has just recorded its 80th consecutive day of temperatures at or above 34.7 degrees.

A regularly updated summary of the current heat wave and the records that it’s breaking, can be found on Wikipedia.

Regarding potential links to climate change, BNC commenter ‘perps’ notes:

In this clip from the “7.30 report” both John Nairn from the Bureau of Meteorolgy and Euan Ferguson from SA Country Fire Authority attribute tthe conditions to climate change as indicated by the IPCC who now say that a trend is emerging. John Nairns also explains why we are seeing these extreme heatwaves – high pressures keep re-establishing over SE Austalia without the intervening lows which used to bring cooler southerly winds.

Further along this line, ABC News radio’s The World Today program ran a story on the Nov 2009 heat wave yesterday: Adelaideans cower under scorching heatwave. Here are a few quotes from me:

NANCE HAXTON: The extreme weather pattern has left many wondering what’s caused the heatwave.

The weather bureau puts it down to a stationary high pressure system over the Tasman Sea, which has prevented cooler air moving up from the Southern Ocean to South Australia and Victoria.

But other experts see another pattern at work. Professor Barry Brook from the University of Adelaide’s Environment Institute says the increasing occurrence of heatwaves in recent years is pointing to climate change.

BARRY BROOK: Heatwaves are going to become more frequent and I think that’s what we’re seeing. That the sort of heatwaves that may have occurred once every few summers in Adelaide in the past, may be a yearly event now and occasionally we’re going to get heatwaves that far exceed anything we’ve had in the past, such as what we had in January this year and in March last year.

NANCE HAXTON: And so that would have policy implications as well?

BARRY BROOK: Well in the immediate term heatwaves are bad for public health, especially those people who are vulnerable to heat stress and haven’t got the ability to cope with that by turning on the air conditioner or going in a pool or whatever.

And that’s what happened in the major heatwave that we had in January, that a lot of elderly people especially died in their homes as a result of heat stroke. So that puts a stress on emergency services and of course it’s bad for the community.

In the broader context hot temperatures early in the year or late in the year put a lot of stress on the plants and animals that live around this area too. It increases their water stress and of course it changes their physiological ability to tolerate heat.

And so all of that put together means more young animals tend to die, more trees die off that are vulnerable and ultimately you get a shift from one type of flora and fauna in a region to another.

And it’s going to get hotter and more hot days, more heatwaves, drier conditions and Adelaide is going to end up looking more desert-like than it currently does today.

Of course they had to end with some quotes from a ’sceptic’; this time it was William Kininmonth with the usual “natural cycle”, “random things” happen, etc. line.

Another regular commenter, John Newlands, points out an interesting implication for energy supply -

Later on I would like to know the capacity factor this week for South Australia’s 800 MW of nameplate windpower. I’ve pointed out before that SA’s power demand of 2.8 GW in March 2007 gives us (Aust pop 22m)/(SA pop 1.1m) = 20 so that a ‘national’ heatwave would give Australia a peak demand of 56 GW…

… Wishes can come true, the AEMO website already had capacity info for 10/11/09

The demand in the South Australian region peaked at 2947 MW at 16:30hrs, due to temperatures reaching a high of 38.6ºC in Adelaide. Wind generation in the afternoon was less than 70 MW. Demand in Victoria reached 9386 MW and temperatures reached 35.2ºC in Melbourne.

70 MW actual/ 800 installed for SA is an instantaneous c.f. of about 9%. Conclusion: wind doesn’t help in heat waves.

Finally, I see that my old haunt of Darwin also cracked the record books – October 2009 was that northern tropical city’s hottest month on record, with an average maximum temperature of 34.8°C. This beat the previous all-time record (Oct 2008) by 0.4°C and followed hot on the heels of its hottest August on record. Makes me glad I left Darwin in February 2007! (at least Adelaide’s heat waves finally break).

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?

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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.

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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.

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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).

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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.

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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.