Designing an autonomous power system for a stand-alone heliostat

Concentrated Solar Power (CSP) offers a number of advantages over photovoltaic at large scale power generation, such as lower cost and the option of thermal energy storage. However, the costs of a power tower plant are dominated by heliostats, which are usually 50% of the entire facility. NASA5s Jet Propulsion Laboratory was awarded funding by the DOE SunShot Initiative to develop a low-cost, rigid foam-based solar concentrator to meet installed cost goals of S75/m2 versus current costs of $200-250/m2. One of the key features of the newly developed design is the stand-alone power system based on PV-panels and a Li-Fe-battery, which reduces operation and installation costs. The approach was validated by building and testing of a small-scale (6m2) heliostat prototype. The design process and findings are described in detail.