As renewable energy prices drop, schools are saving millions, while teaching students about technology. Their solar capacity has nearly doubled in three years. The number of schools powered by solar is growing quickly. About 5 percent of all K-12 U.S. schools are now powered by the sun, and their solar capacity has almost doubled in the last three years, according to a new study by the Solar Energy Industries Association (SEIA), The Solar Foundation, and Generation 180, a clean energy nonprofit.The nearly 5,500 schools using solar power today have a total of 910 megawatts of solar capacity, enough to power 190,000 homes, according to the study.The biggest reason for the surge is the economic benefits of solar energy. Drastic declines in price have made it financially viable for schools. Both public and private schools are reducing their electricity bills with solar, leaving them more money to spend on educational programs, according to the research. Many are also incorporating renewable energy into their science, technology, engineering and math (STEM) lessons.