When Renewable Is Not Sustainable

Ethanol and solar power deplete land and water resources.

Renewable energy is sold to the public as an environmentally benign alternative to energy produced by fossil fuels. With respect to ethanol and solar power, however, the debate has ignored how land and water use is affected by refining ethanol, growing corn and siting solar plants.

Energy production requires water. Producing petroleum, natural gas, coal or methane consumes a lot of water, but much less than it takes to make ethanol. In 2008, researchers at Virginia Tech quantified the amount of water it takes to produce one million British Thermal Units (BTUs): natural gas requires three gallons, ethanol as much as 29,100 gallons.

Even in a state-of-the-art refinery that recycles its water, four gallons of water are consumed for every gallon of ethanol produced. In 2007, Congress enacted the Energy Independence and Security Act, which mandates the production of 36 billion gallons of ethanol per year by 2022