Solar window glass using Sphelar spherical solar cells

At PV EXPO 2010, Kyosemi exhibited solar window glass, which generates power using spherical solar cells called Sphelar, developed by Kyosemi. Sphelar are spherical solar cells 1.8 mm in diameter, made from solidified silicon droplets. They can be used in various applications, including “flexible” solar cells where the spheres are arranged on a soft film backing, and dome-shaped modules. Because they are highly transparent to light, these cells are expected to be used in solar window glass. The solar cells can be applied to transparent plastics, such as polycarbonate, as well as glass. So the flexibility of Sphelar could also be utilized in car windows. Sphelar cells are manufactured using a special process in which molten silicon is allowed to fall freely, so it naturally forms spheres under weightless conditions. Because there’s little material loss in this process, it enables costs to be reduced substantially and silicon to be utilized effectively.