In April, California Gov. Jerry Brown signed into law an ambitious mandate that requires the state to obtain one-third of its electricity from renewable energy sources by 2020. Twenty-nine states and the District of Columbia now have renewable electricity mandates, and there is also support at the federal level, says Robert Bryce, a senior fellow at the Manhattan Institute.
But while energy sources like sunlight and wind are free and naturally replenished, converting them into large quantities of electricity requires vast amounts of natural resources -- most notably, land.
Consider California's new mandate.
- The state's peak electricity demand is about 52,000 megawatts.
- Meeting the one-third target will require (if you oversimplify a bit) about 17,000 megawatts of renewable energy capacity.
- The math is simple: to have 8,500 megawatts of solar capacity, California would need at least 23 projects the size of Ivanpah, covering about 129 square miles, an area more than five times as large as Manhattan.
- While there's plenty of land, projects as big as Ivanpah raise environmental concerns.
- In April, the federal Bureau of Land Management ordered a halt to construction on part of the facility out of concern for the desert tortoise, which is protected under the Endangered Species Act.
In the rush to do something -- anything -- to deal with the problem of greenhouse gas emissions, environmental groups and policymakers have determined that renewable energy is the answer. But all energy and power systems exact a toll, says Bryce.
Hawaii's renewable energy mandate is among the nation's most ambitious. Hawaii law requires electric utilities to meet a renewable portfolio of 10%, 15%, 25% and 40% by December 31, 2010, 2015, 2020 and 2030, respectively.
The lesson for Hawaii where flat space and any space in general is at a premium is that land-hungry renewable energy options are not likely to be a major part of the solution.