Climate change

June 6, 2011

Renewables and efficiency cannot fix the energy and climate crises (part 2)

by Barry Brook

This post continues directly on from Part 1 (please read that if you’ve not already done so!). I also note the flurry of interest in the new IPCC WGIII special report on renewable energy prospects through to 2050. I will have more to say on this in an upcoming post, but in short, it fails to address — with any substance — any of the significant problems I describe below, or in the previous post. What a disappointment!


Renewables and efficiency cannot fix the energy and climate crises (part 2)

Renewable energy cannot provide reliable 24-hour, 7-day-a-week  power to meet baseload demand

The minimum amount of power that a city or country demands usually occurs at night (when most people are asleep); this is called the electricity ‘baseload’. Some have claimed that it is a fallacy to argue that all of this demand is needed, because utilities tend to charge cheap (‘off peak’) rates during these low-use periods, to encourage more uptake (by everything from factory machinery to hot water systems). This is because some types of power stations (e.g., coal and nuclear) are quite expensive to build and finance (with long terms to pay off the interest), but fairly cheap to run, so the utility wants to keep them humming away 24 hours a day to maximise returns. Thus, there is some truth to this argument, although if that energy is not used at night, extra must instead be supplied in the day.

Some critical demand, however, never goes away – the power required to run hospitals, police stations, street lights, water and sewerage pumping stations,  refrigerators and cold storage, transport (if we are to use electric vehicles), and so on. If the power is lost to these services, even for a short while, chaos ensues, and the societal backlash after a few such events is huge. On the other side of the energy coin, there are times when huge power demands arise, such as when everyone gets home from work to cook their meals and watch television, or when we collectively turn on our air conditioners during a heatwave. If the energy to meet this peak demand cannot be found, the result can be anything from a lot of grumpy people through to collapse of the grid as rolling blackouts occur.

Two core limitations of wind, solar and most other renewable systems is that: (i) they are inherently variable and are prone to ‘gambler’s ruin‘ (in the sense that you cannot know, over any planning period, when long stretches of calm or cloudy days will come, which could bring even a heavily over-compensated system to its knees), and (ii) they are not ‘dispatchable’. They’ll provide a lot of power some of the time, when you may or may not need it, and little or none at other times, when you’ll certainly need some, and may need a lot. In short, they can’t send power out on demand, yet, for better or worse, this is what society demands of an electricity system. Okay, but can these limitations be overcome?

Large-scale renewables require massive ‘overbuilding’ and so are not cost competitive

The three most commonly proposed ways to overcome the problem of intermittency and unscheduled outages are: (i) to store energy during productive times and draw on these stores during periods when little or nothing is being generated; (ii) to have a diverse mix of renewable energy systems, coordinated by a smart electronic grid management system, so that even if the wind is not blowing in one place, it will be in another, or else the sun will be shining or the waves crashing; and (iii) to have fossil fuel or nuclear power stations on standby, to take up the slack when needed.

The reality is that any of these solutions are grossly uneconomic, and even if we were willing and able to pay for them, the result would be an unacceptably unreliable energy supply system. Truly massive amounts of energy would need to be stored to keep a city or country going through long stretches of cloudy winter days (yes, these even occur in the desert) or calm nights with little wind and no sun, yet energy storage (batteries, chemical conversion to hydrogen or ammonia, pumped hydropower, compressed air), even on a small scale, is currently very expensive. A mix of different contributions (solar, wind, wave, geothermal) would help, but then we’d need to pay for each of these systems, built to a level that they could compensate for the failure of another.

What’s more, in order to deliver all of our regular power demand whilst also charging up the energy stores , we would have to ‘overbuild’ our system many times, adding to the already prohibitive costs. As a result, an overbuilt system of wind and solar would, at times, be delivering 5 to 20 times our power demand (leading to problems of ‘dumping’ the excess energy that can’t be used or stored quickly enough or in sufficient quantity), and at other times, it would deliver virtually none of it.

If you do some modelling to work through the many contingencies, you find that a system which relies on wind and/or solar power, plus large-scale energy storage and a geographically dispersed electricity transmission network to channel power to load centres, would seem to be 10 to 40 times more expensive than an equivalent nuclear-powered system, and still less reliable. The cost to avoid 1 tonne of carbon dioxide would be >$800 with wind power compared with $22 with nuclear power.

The above critiques of renewable energy might strike some readers as narrow minded or deliberately pessimistic. Surely, isn’t it just a matter of prudent engineering and sufficient integration of geographically and technologically diverse systems, to overcome such difficulties? Alas, no! Although I only have limited space for this topic in this short post, let me grimly assure you that the problem of ‘scaling up’ renewable energy to the point where it can reliably meet all (or even most) of our power needs, involves solving a range of compounding, quite possibly insuperable, problems. We cannot wish these problems away — they are ‘the numbers’, ‘the reality’.

Economic and socio-political realities

Supporters of ’100% renewable energy’ maintain that sunlight, wind, waves and plant life, combined with vast improvements in energy efficiency and energy conservation leading to a flattening or reduction in total energy demand, are the answer.  This is a widespread view among environmentalists and would be perfectly acceptable to me if the numbers could be made to work. But I seriously doubt they can.

The high standard of living in the developed world has been based on cheap fossil (and nuclear) energy. While we can clearly cut back on energy wastage, we will still have to replace oil and gas. And that means a surge in demand for electricity, both to replace the energy now drawn from oil and gas and to meet the additional demand for power from that third of the world’s people who currently have no electricity at all.

Critics do not seem to understand – or refuse to acknowledge – the basis of modern economics and the investment culture. Some dream of shifts in the West and the East away from consumerism. There is a quasi-spiritualism which underpins such views. Yet at a time of crisis, societies must be ruthlessly practical in solving their core problems or risk collapse. Most people will fight tooth-and-nail to avoid a decline in their standard of living. We need to work with this, not against it. We are stuck with the deep-seated human propensity to revel in consuming and to hope for an easier life. We should seek ways to deliver in a sustainable way.

A friend of mine, the Californian entrepreneur Steve Kirsch, has put the climate-energy problem succinctly:

The most effective way to deal with climate change is to seriously reduce our carbon emissions. But we’ll never get the enormous emission reductions we need by treaty. Been there, done that – it’s not going to happen. If you want to get emissions reductions, you must make the alternatives for electric power generation cheaper than coal. It’s that simple. If you don’t do that, you lose.

Currently, no non-fossil-fuel energy technology has achieved this. So what is stopping nations replacing coal, oil and gas infrastructure with renewable energy? It is not (yet) because of any strong, society-wide opposition to a switch to renewables. No, it is economic uncertainty, technological immaturity, and good old financial risk management. Despite what ’100% renewables’ advocates would lead you to believe, it is still far from certain in what way the world will pursue a low-carbon future. You have only to look at what’s happening in the real world to verify that.

I’ve already written about fast-growing investment in nuclear energy in Asia. China, for instance, has overcome typical first-of-a-kind engineering cost overruns by building more than 25 reactors at the same time, in a bid to bring costs to, or below, those of coal.

In December 2009, there was a telling announcement from the United Arab Emirates (UAE), which wish to sell their valuable natural gas to the export market. Within the next few years, the UAE face a six-gigawatt increase in demand for electricity, which includes additional power required by an upgraded desalination program. Despite being desert-based with a wealth of solar resources, the UAE decided not to build large-scale solar power plants (or any other renewable technology). In terms of economics and reliability, the numbers just didn’t stack up. Instead, they have commissioned a South Korean consortium to build four new generation III+ APR-1400 reactors, at a cost of $3,500 a kilowatt installed – their first ever nuclear power plants.


Nuclear power, not renewable energy or energy efficiency, will probably end up being the primary global solution to the climate and energy crises. This is the emergent result of trying to be honest, logical and pragmatic about what will and will not work, within real-world physical, economic and social constraints.

If I am wrong, and non-hydro and non-combustible renewables can indeed rise to the challenge and ways can be found to overcome the issues I’ve touched on in these two posts, then I will not complain. After all, my principal goal — to replace fossil fuels with sustainable and low-carbon alternative energy sources — would have been met. But let’s not play dice with the biosphere and humanity’s future on this planet, and bet everything on such wishful thinking. It would be a risky gamble indeed.


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