In theory, the U.S. military could be a major driver of cleaner forms of energy. In recent years it's even been making noises along those lines: The Pentagon is, after all, well aware that spending $14 billion each year on oil (and, worse, paying up to $400 per gallon for fuel in a war zone) is untenable, and has recently started ordering planners to consider efficiency measures and look at alternative fuels.

So far, though, he results have been inconsistent. When Marine Corps Maj. Gen. Richard Zilmer asked for 183 solar- and wind-power stations to be deployed in Iraq, which would help curb oil use and hence reduce the need for frequent supply convoys—potentially saving lives—his request was turned down. But now, as Noah Schactman reports, the Army has just announced a plan to partner with the private sector and build a massive 500-megawatt solar thermal plant at Fort Irwin in the Mojave desert. (Here's more on solar thermal's vast potential.) This is all part of a huge new Army initiative to reduce energy costs, promote conservation, and "reduc[e] the risk of power disruption." It sounds like this time they really mean it, which would be a big deal, although it's hard to say for sure.

--Bradford Plumer