Concentrated Solar Power Company REhnu Raises $872

Founded in 2009, REhnu’s solar thermal technology was originally developed at the University of Arizona by Roger Angel, the company’s CEO, who is a member of the National Academy of Sciences and the American Academy of Arts and Sciences, a Fellow of the Royal Society, a MacArthur Fellow, and a Kavli Laureate, sharing the 2010 prize in Astrophysics.

REHnu’s technology uses “triple junction” cells, which convert twice as much sunlight energy into electricity as do silicon cells, according to the company. Concentration cost is minimized by focusing the sunlight with large glass reflector dishes pointed at the sun.

The company’s reflector dishes, steel components and receivers are manufactured separately using large-scale mass production methods and shipped independently to an assembly facility at the solar farm. Its integrated spaceframe units are then driven out to their location on the farm and mounted on tracker drive pedestals.

REhnu’s dish reflectors are made from float glass, the same type manufactured in huge volume for windows. The glass is first molded into shape, and then back-silvered for high reflectivity. For gigawatt scale production levels, the shaping and silvering steps will be built into a dedicated float glass factory.

REhnu’s reflectors have a paraboloidal shape, so that when pointed at the sun they bring the light to an intense point focus. Similar reflectors of back-silvered glass, but with cylindrical curvature to bring sunlight to a line focus, have long been used at large solar thermal plants in the Mojave Desert. Here they have proven to be robust and to have excellent mechanical and chemical stability, based on decades of operation.