Energy, sustainability and the left.

AuthorTrainer, Ted

Just about everyone assumes that the energy and greenhouse problems can be solved by moving from the fossil fuels to renewable energy sources such as the sun and the wind, enabling us all to go on pursuing affluent lifestyles and economic growth. I think this is seriously mistaken.

For many years I have been working on the potential and limits of renewable energy and have groped towards a more effective way of assessing the essential themes. The journal Energy Policy recently published my approach to estimating the investment cost of a global renewable energy supply. (Trainer 2010a) Following is a summary of the argument.

The first step was to take the commonly estimated 2050 world energy demand we seem to be heading for, which is 1000 Exajoules per annum, or 28 billion kilowatt-hours, twice the present figure.

Then I assumed the following:

  1. Final demand (after losses converting the primary energy into useful forms such as electricity) would be .7 of primary energy;

  2. Energy conservation, etc., effort would improve the efficiency of energy use by one-third,

  3. 60% of transport could be shifted to electricity, cutting energy needed by 2/3;

  4. One billion hectares could be found to produce liquid fuel;

  5. Capture and burying of C02 could enable the safe generation of electricity, about 10% of the target amount of energy needed (96 Exajoules p.a.);

  6. Hydro-electricity and nuclear sources could continue to make the same contributions they make now. Some of these assumptions are optimistic (and I am not saying they are valid).

The resulting quantity of electricity to be provided was then divided equally between wind, PV and solar thermal sources. The biomass was allocated to transport demand. All the other renewable sources provide electricity, so if the energy in nonelectrical form is to come from electricity via hydrogen generation, then at least three times as much energy would have to be generated, given the highly energy-inefficient nature of that path.

I then took the available evidence on the winter output and probable future cost of windmills, PV panels and solar thermal plant. This enabled tentative conclusions on the numbers of each of these required to meet the global demand. I added these costs and divided by 25 to give an annual investment amount that would be required (i.e., making the standard assumption that plant would last 25 years). Even when you assume that world GDP in 2050 would be three times as much as it is today, the required annual investment would be 10 times the proportion that world energy investment makes up now. (Birol, 2003; IEA, 2010.)

Several significant cost factors were not taken into account, including the long distance transmission lines from solar thermal sites located in deserts, the biomass energy system, the hydro-electricity system, and the coal burning and geo-sequestration systems. If these could be taken into account they might double the investment sum arrived at above.

The exercise is somewhat crude given that one cannot be too confident about the assumptions made, but the magnitude of the conclusion means that the assumptions would have to be very different before it was remotely possible to afford the quantity of renewable energy required.

Note that if the nine billion people we are likely to have on earth by 2050 were to have the per capita energy use people in Australia are heading for by then, the target would have to be around four times as great as the 1 OOOEJ/y target taken in this exercise. So unless my assumptions are wildly incorrect there is no possibility of all people living as affluently as we do in rich countries today on renewable energy (plus nuclear energy and coal burning with geo-sequestration).

Energy is only one item among many in the general "limits to growth" list of problems our society is running into. We are also obviously seriously depleting most other resources, condemning about four billion in the Third World to deprivation (while the few in rich countries take most of the world's resource wealth, mostly from them), and destroying the ecosystems of the planet. All these problems are basically due to the fact that there is far too much producing and consuming going on. We are far beyond the levels of resource use that...

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