Did everyone hear the story on NPR this morning - Renewable Energy Needs Land, Lots Of Land by Christopher Joyce? Pretty interesting story and figures - for instance Rob McDonald a Landscape ecologist, with the Nature Conservancy) has the following, "Whenever you switch to renewables, the amount of space it takes to make that energy will go up:

To get a terawatt hour from coal, you need 9.7 square kilometers, on average. And then for wind power it, takes about 72 square kilometers. And by the time you get up to something like corn ethanol, it's like 350 square kilometers."

Seemed to miss the inclusion of the acres with diminished usefulness due to damage caused by the pollution associated with coal, etc.. ?

It's complicated. I know Denise.