Tuesday, December 05, 2006

Giant Footprints

Two stories in today's Wall Street Journal illustrate one of the inevitable consequences of our shift away from fossil fuels and toward renewables, which are generally much more diffuse. The front page of the Journal carried a lengthy exposé (subscription may be required) on the damage to the Borneo rainforest, shared between Indonesia and Malaysia, caused by these countries' efforts to expand palm oil production for biofuel. Another piece looked at the expansion of concentrated solar power (CSP) collectors in Spain. In both cases, the footprint of renewable energy is much larger than that of the traditional energy sources it is meant to augment or displace. With non-hydro-electric renewable energy still supplying only a few percent of global energy demand, this trend is in its very early stages. Although the final verdict on the sustainability of this effort is unresolved, the conversion to renewable energy will indisputably transform the earth's surface as much as any past endeavor of mankind.

This isn't intended as a criticism of renewable energy, per se. Rather, it's a reminder that every choice we make concerning energy carries consequences. Oil and gas have their own problems, but as their technology has improved, developments such as 3-d seismic and horizontal drilling have reduced their footprint on the landscape, by boosting the productivity of each well drilled. Fundamentally, though, even where the countryside has been turned into a veritable moonscape of pumping units, pipelines and cogeneration steam generators, such as in the Kern River and Midway-Sunset oil fields near Bakersfield, California, the energy produced from this modest patch of land exceeds the entire net contribution of all the corn that's turned into ethanol in the Midwest. Oil and gas are highly-concentrated vintage sunlight, and our efforts to harness today's sunlight--including the wind it creates--must necessarily cover vast expanses of land or sea, to capture equivalent quantities of energy.

To the long-standing land-use competition among wilderness, agriculture (for food), recreation, and human habitation, we must now add "energy farming." The latter encompasses wind, solar, and biofuels, and it complicates an already intricate dance between the forces of development and preservation. I've devoted a lot of space on this blog to my concerns about over-estimating rate at which alternatives can replace conventional fuels, largely as a function of the time lags involved. However, I think this competition for surface area could be just as important, because it naturally leads to the NIMBY-ish constraints that have already slowed the development of wind power, at least here and in the UK. Unless we see rapid progress in some new highly-concentrated form of energy, such as the dry-rock geothermal energy mentioned in a comment on yesterday's posting, we're going to be dealing with this problem for generations.

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