Solar cells have been around since the 1950s. But now there is a race to develop transparent solar cell that can cover windows of buildings and still capture the sun’s light for electricity. There are three kinds of light that reach our planet from the sun. They are ultraviolet light, or UV, visible light, and infrared light. Together they make up what is called the solar spectrum. Troy Townsend is a solar cell researcher at St. Mary’s College of Maryland. He says working with the transparent solar technology for windows means you cut the efficiency in half. That is because you are letting visible lightlight you can seepass through the solar cells instead of capturing and using that light to make electricity. That leaves only light from the ultraviolet and infrared parts of the light spectrum to make electricity.