We’re all familiar with standard photovoltaic solar panels, and many of us are starting to become acquainted with solar thermal tech that uses the sun’s heat to generate power as well. But there’s also a third option: Over a dozen startups are currently working on ways to use mirrors and lenses to concentrate sunlight hundreds of times onto tiny, highly efficient solar cells. Known as concentrating photovoltaic technology, the systems are meant to cut back on one of the most expensive parts of traditional PV: the silicon-based solar panel. For details on 13 companies in this space, head over to Earth2Tech.