June 20th, 2010

Euan Mearns at the Oil Drum blog draws this depressing chart from BP’s (one good deed) Statistical Review of World Energy.

World primary energy production 1970-2009. In 2009 fossil fuels (oil, natural gas and coal) accounted for 87.5% of all the energy we used. Wind, solar and geothermal combined accounted for 0.4%. (Mearns’ caption, edited)

But compound interest comes to our rescue.  I played with BP’s data too. The 10-year annual growth rates for geothermal, wind and solar PV capacity were respectively 3.0%, 28.3%, and 35.1%, as fitted by Excel. The boom is not slowing down; the one-year rates 2008-2009, during a sharp downturn, were even  a tad higher.

Total primary energy consumption fell in 2009; in the OECD countries, by more than GDP, offsetting rising use in China and India. It’s reasonable for a simulation therefore to assume flat total primary energy demand over the coming decades. I converted everything to electrical units – continuous MW equivalents  – using BP’s conversion factors. Mearns follows BP in converting everything to tonnes of oil equivalent, a piece of propaganda we should resist.

If you just project these historic growth rates on that basis, primary energy from renewables can replace coal entirely by 2023 and all fossil fuels by 2028.

This won’t and can’t happen just like that.  Long before we get near full replacement, intermittent solar PV and wind will hit constraints of energy management that require expensive retooling of the electric grid and cultural changes in patterns of use. Replacing oil for transport requires a major shift in technology for cars, and something entirely new for aviation, shipping and metals. These discontinuities are concealed by any blithe conversion of energy to a single metric like electricity, for different forms are not true substitutes.

On the other hand, the exercise excludes solar thermal energy. It’s also not credible on geothermal. This combines one old technology of tapping underground steam, which is only available in a few places, and a new one, fracking deep hot dry rocks, which has vast potential but is still experimental with an insignificant installed base. So geothermal will either stall or, hopefully, take off. (Note to Brett: it’s continuous. Note to language police: I concede in advance that geothermal is only truly renewable on timescales of centuries, in the short run it’s a form of mining, but even temporary exhaustion is millennia ahead.)

Credit Géothermie Soultz (European hot rock demonstration plant)

The exercise underlines my earlier point that policy should concentrate on maintaining effective demand for the shift to renewables rather than spending fortunes looking for an unnecessary magical breakthrough. Precommercial technologies like hot rocks and fusion still need direct support, to widen the portfolio. But even without them, we have working technologies, we have businesses making money out of them, we have engineers making them better every day. The main thing we need to do is keep the market prices in their favour, and plan ahead to keep the road to sustainability clear. If the closet socialist American public insists on regulation against fossil fuels [update: but see Robert Waldmann's stout defence of the great A~P~ in comments] rather than the more efficient market mechanisms preferred in Europe, that will also do.

Spreadsheet with my working here.

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4 Responses to “The renewable tank: 99.6% empty or 0.4% full?”

  1. Brett Bellmore says:

    Note to James: I knew that already…

  2. Re
    “Total primary energy consumption fell in 2009; in the OECD countries, by more than GDP, …It’s reasonable for a simulation therefore to assume flat total primary energy demand over the coming decades. ” Did you notice that 2009 was a somewhat unusual year for the world economy ? Forecasting decades based on one year of data is always unreasonable. Forecasting decades based on 2009 sounds rather like a joke. I’m subjectively certain that you base your forecast on the limited supply of petroleum and a forecast of its price in the not too distant future. In any case, I agree with your forecast for that reason.

    By the way, much of the unusual behavior of economies in 2008 and 2009 had something to do with forecasting using exponential trends. I don’t compare your trends to house price trends, but you do note that there are limits to renewables.

    In poll after poll a majority of the American public supports cap and trade.
    http://www.pollingreport.com/enviro.htm and search for “cap.” Pollingreport gives a dog’s lunch of polls on that page, but I haven’t found one without a majority for cap and trade (I coun’t 50% as the smallest majority not the larges plurality). Oops CNN April 23-26 2009 but I haven’t counted how many had majority support.

    The closet socialists are in the Senate (where a majority has voted for cap and trade). Still, I agree, any port in a storm and some command and control is just what Republican obstructionists deserve. Actually it may be what they want. They seem to have become not only closet socialist but also Leninist in their view that the worse it is the better it is).

  3. Brett: You attach great importance to round-the-clock availability in power sources, hence your support for fission energy. So you should be an even more enthusiastic supporter of geothermal energy, which has availabilities of 95-99%. The risks are all in the setup and the working life, once the plant is in there’s very little to go wrong. The average for nuclear is 80%.

    Robert: what forecast? I said I don’t believe in my exponential projection. But for that purpose, it makes little difference what low growth rate you put in for the fossil tortoises; the renewable hares will overtake them in a few decades. Even with an unrealistic 5% growth rate for fossil fuels, renewables overtake coal in 2026 and all fossil in 2031. My point was that the task of policymakers is to keep the existing ten-year renewables boom going as long as possible, not to start one from nothing.

    But I think I can still make a fair armchair case for my flat-energy-demand assumption. The decrease in energy intensity in the OECD looks like a new trend; surely the unemployed driving less and turning down the heating can’t account for it. Firms and households getting serious about energy efficiency looks more like it. (Data, anyone?) So when OECD growth resumes, we could expect roughly flat overall energy demand there. We also have to think the Chinese are serious about decreasing the carbon intensity of output, which implies progress on efficiency as well as substitution. And, as you say, oil has peaked or will do very soon.

    On the American public: I was lazily going by the survey reported by Krosnick in the linked op-ed, which gave large majorities opposing taxes on gasoline (and, oddly, electricity, which no-one is suggesting SFIK). Cap-and-trade is effectively a carbon tax, and would be portrayed as such by Republicans in November. Poll responses are, Krosnick suggests, very sensitive to the exact wording of questions. But his article strongly confirms your evidence that the American public is much more supportive of strong action than Democrats in Congress. Denialism has little purchase in the general population; it’s essentially an ideological crack smoked in right-wing Beltway think tanks.

  4. Brett Bellmore says:

    Actually, I think geothermal is a great idea where feasible. It has no lack of technical problems, such as mineral deposits in heat exchangers, but it’s very promising. As far as solar goes, there are concepts for solar power with equivalent availability, such as the solar updraft tower. (Which can also tap the same forces that power thunderstorms.)

    So, you see, my opposition to ‘renewable’ energy isn’t complete. I just think it needs to be rationally judged as to it’s suitability for supplying the grid. At present costs of energy storage, sources which don’t work 24/7, and especially sources that don’t provide power predictably can’t supply much of our needs. That’s a technical judgment, not a moral one.

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