CITIZEN POWER ALLIANCE

Wind, hydro, and all the "alternate" sources of energy have been dubbed "green" because they are supposedly clean, renewable, and sustainable. In fact, what being "green" really means is that they all require vast amounts of land.

In a 2007 paper – well on its way to becoming a classic – Jesse Ausubel, director of the program for the human environment at Rockefeller University, calculated the amount of wood it would take to run one standard 1,000-megawatt electrical plant, the kind that can power a city the size of Cincinnati. Feeding the furnace year-round would require a forest of one thousand square miles. We have 600 such coal plants around the country now – to burn wood instead would require a forest the size of Alaska.

Glen Canyon Dam, which can produce 1,000 megawatts of electricity, is backed up by a reservoir 250 miles square (Lake Powell, in Arizona and Utah). That's why we stopped building dams in the 1960s – because they were drowning scenic canyons and displacing populations.

Those 30-story windmills produce 1.5 megawatts apiece – about 1/750th the power of a conventional generating station. Getting 1,000 megawatts would require a wind farm 75 miles square.

In a January cover story for Scientific American, three leading solar researchers proposed meeting our electrical needs in 2050 by covering southwestern desert with solar collectors. The amount of land required would be 34,000 square miles, about one-quarter of New Mexico.

And that's where biofuels went awry. Nobody ever bothered to calculate how much land they would require.