Monday, July 13, 2009

 

Can We Run Industrial Civilization on Renewables?

In public discourse on implementing renewable energy sources, it is just assumed that we will be able to transition (maybe not seamlessly, but somehow) away from fossil fuels and to renewable sources that will keep societies and economies running more or less just as they have up to now. We will have more technological advances, the airlines will keep flying, the fleets of motor vehicles will keep rolling, and — of course — we will have perpetual economic growth. But this scenario takes some things for granted, and tragically overlooks the essential role of fossil fuels.

Before going any further, I would like to acknowledge that I didn’t just come up with this essay out of the blue. I benefited greatly from a series of blog posts by Jeff Vail called “The Renewables Hump.” For those with the time, I recommend reading the whole series (you can find a list of all the posts with links here). I think Jeff is a little more sanguine than I am about the possibilities for keeping the show on the road, despite the fact that he himself has raised issues which cast serious doubt on those possibilities. So in a way I have brought together some ideas he has presented and flavored them with my own thoughts.

There is much disagreement over EROEI. Wind energy proponents are citing some fantastic (in the literal sense of the word) figures. Of course there is the endless argument over where to draw boundaries, but all the inputs are not readily apparent.

One apparent input is the energy embodied in the steel and other metals and materials that make up a wind turbine or a biofuel reactor or what have you. That part is relatively easy to calculate, but in fact I believe that is the smaller input.

The more high-tech the machine, the greater the input in terms of the energy embodied in the technology itself. For example, the design, testing, manufacturing, installation, and maintenance of the hardware requires the talents of many scientists, engineers, steelmakers, machinists, technicians, and other skilled people. They weren’t born with those advanced skills and knowledge; it required many years of education, from elementary school through university, plus years of experience on the job. Start adding up the energy consumed in their education and training, and you will no doubt come up with an amount that is far greater than the energy contained in the materials of the structures themselves. You don’t need to be a rocket scientist yourself to see that society expends a huge amount of energy producing just one rocket scientist. We often hear about the need to invest lots of money in education, but of course money is just a means of accessing energy, and we need to focus on the energy that is being invested in educating and training scientists, engineers, and skilled workers. And because people don’t live forever, we need to keep investing lots of energy in education and training if technological civilization is to continue. Therefore, that energy input has to be taken into account when calculating the net energy of renewables (or anything else, for that matter). And a vital question here is: Can renewables be counted on to churn out that much surplus energy?

Another vital question is: Can renewables really replace fossil fuels? Let’s for the moment ignore things like the petrochemical industry and focus on the use of coal and oil for their energy value. Proponents of renewables claim that achieving a certain EROEI will produce enough surplus energy to build many more of the same machines. I have not seen a detailed exposition of this claim, but I assume they are calculating energy equivalencies, finding that a wind machine, for example, produces electricity that is equivalent to the energy in a certain amount of coal and oil, and pronouncing it a success. But renewables produce much electricity, and relatively small amounts of liquid and solid fuels. Recall that making hardware starts with mining ore, smelting it, making steel, casting parts, and machining them. Are they going to run cables from a wind machine to a blast furnace and smelt iron ore? Having never seen this matter addressed anywhere, I imagine that continued mining and smelting is just assumed. But since we are trying to replace fossil fuels, we have to replace all their significant uses or the whole exercise is meaningless. Recall that fossil fuels will become prohibitively expensive long before they run out.

Finally there is the matter of legacy infrastructure. Proponents of renewables seem to have given little or no thought to the very large amount of fossil fuel energy embodied in the infrastructure of industrial civilization, such as that for metals (mines, mining machines, smelting facilities, steel mills, machine shops, etc.) and that for oil (drilling equipment, pipelines, terminals, oil tankers, refineries, etc.). How about railroads, factories, trucks, and highways? All these exist thanks to fossil fuels. Do renewables proponents claim that all this and more can be maintained with the energy produced by renewables? Do they realize that renewable energy hardware is piggybacked on this fossil fuel-built platform?

Proponents of renewable energy are going off half-cocked in claiming that we can keep industrial civilization running smoothly with the energy produced by renewable energy equipment. I agree that we should build as much renewable capacity as possible, as soon as possible. In fact, I advocate a crash program for doing so. But I am under no illusion that it will save industrial civilization. It will just help us achieve a soft landing.

Those who claim that renewables can prop up industrial/technological civilization need to account for all these problems instead of proclaiming a new “green” age with more economic growth.



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