Alternate energy
Congratulations on your excellent series on future energy supply. It will provide a good foundation for educating the public on this vital subject. With such a broad topic, some issues were bound to stimulate more discussion. Let's roll!
While government policies (taxing Peter to pay Paul) can promote the initial development of alternate energy sources, in the long term those sources will have to make sense thermodynamically. Fundamentally, what the energy supply industry does is amplify available energy. In the oil industry, we take some of the human race's hard-won store of energy and use it to drill wells and build facilities to provide future energy supplies. Doing an energy input-output analysis on that process is an accounting nightmare, but some brave souls have tried. Their figures suggest that a large conventional oil field might produce 50 units of energy over its life for each unit of energy used in development and operation —a 1:50 amplification.
The best modern windmill in an ideal location will probably achieve an energy amplification over its life of only 1:3, and that is before allowing for performance drag due to the windmill producing electricity at times when there is no demand for it. Even that humble performance is good compared to the modern photovoltaic cell, which is expected to produce approximately as much energy over a nominal 20-year working life as it takes to make that cell in the first place, a nonamplification of 1:1. Unfortunately, the energy amplification factor for tax-favored ethanol is even less than 1:1.
We have to keep plowing some of the total produced energy from any source back into securing future energy supplies. Only the net energy after this need has been met is available for useful purposes, such as providing water, food, shelter, or transportation. As we move from high-amplification energy sources like large conventional oil fields to lower-amplification sources (i.e., almost anything else), there will have to be a huge expansion in total energy production simply to maintain the current level of net energy availability. The impact of declining energy amplification on future total energy demand is often overlooked.
Another often-overlooked factor is the environmental impact of using renewable resources. The negative environmental consequences of hydroelectric dams are already well known. The potential global climate impact of using wind power has not been studied extensively so far, but some voices in the environmental community are already urging caution. Wind is an expression of global climate, as the Sun's differential heating of the Earth causes air movement on a planetary scale. When we erect a windmill, we slow down that air movement. At some currently unidentified level of wind power production, there would undoubtedly be an impact on global climate.
The only nonfossil, large-scale, long-term, environmentally tolerable source of energy feasible with today's technology is the nuclear breeder reactor. The sooner we get back to serious development of that energy source, the more secure the future of the human race will be.
Gavin Longmuir
Consulting Petroleum Engineer
Stanley, N. Mex.