What do you get when you add public land in sunny Western states and a federal government that wants to develop renewable energy? The answer: an announcement by the Interior Department last week that it selected about two dozen potential sites for large-scale solar power installations on public lands. The sites are in six states: California, Arizona, Nevada, Utah, Colorado, and New Mexico. The Bureau of Land Management has 120 million acres in the six states, and 22 million acres could be identified as solar energy zones, but only 214,000 acres will be considered.