In the last several years costs for solar power have dropped significantly, driven by advances in manufacturing technology, improvements in efficiency, and government support, among other things. Apparently, that's led some solar power plant projects to switch from using solar thermal technology—which involves concentrating sunlight to generate high temperatures that can be used to generate electricity—for photovoltaics, solar panels that convert sunlight to electricity directly. At least that's what Reuters reported today.

Reading between the lines, the issue may also be something called bankability. Solar panels are established technology—banks have a pretty good idea how long they'll last and what the return on investment will be. Much of the solar thermal technology being deployed now hasn't been tested on a large scale for long periods of time, which can make financing harder. Indeed, in one case, "the company would have needed to secure loan guarantees from the U.S. Department of Energy aimed specifically at new technologies," the report said.