One of the biggest challenges of switching to clean energy sources is finding a place to store excess power. That's relatively easy on a small scale, but it's much more daunting for your utility company. Southern California Edison is apparently ready to take on that challenge, however. It just launched the Tehachapi Energy Storage Project, a large-scale experiment in using lithium-ion batteries (608,832 of them, to be exact) to preserve unused electricity. For the next two years, the 32 megawatt-hours array will scoop up leftover energy from nearby sources, including a wind turbine area; SCE will be watching closely to see how the lithium-ion packs improve its grid's real world performance.