Twisting heliostat technology enabling high temperature industrial processes and solar electric power generation

The twisting heliostat is to develop and demonstrate a new way to strongly concentrate sunlight to make heat, as a source of renewable thermal energy. The goal is to obtain a more intense focus than previously possible, to reach higher temperatures and thus open up more commercial uses. Our approach is similar to that used already in some commercial electrical power plants, where sunlight is focused by thousands of mirrors surrounding a central, tower-mounted receiver. The mirrors are mounted on and turned by heliostats to aim the light correctly as the sun moves across the sky. The difference is that our heliostats will be of a new “twisting” type. Conventional heliostats with fixed, concave shape can focus sunlight to a sharp disc image of the sun only at that time of day when the sun strikes the mirror at the precise angle for that shape. By twisting our heliostats using the struts in the back, we can keep changing their shapes to keep each image sharply focused through the day. With twisting engaged, the concentration increases by nearly 4 times, so that temperatures well over 1,000 °C are easily reached. The potential impact of the project is to bring this new technology into the commercial domain, where it could both allow the use of solar energy for high-temperature industrial processes (CST) and improve the efficiency of solar electric power generation (CSP).