On-grid performance of REhnu’s 8-mirror CPV-T tracker

REhnu has built and tested two 6 kW CPV-T trackers using dish-receiver architecture. In these trackers, only the light collection elements are large, namely mirrors on dual axis trackers. The inherently small parts, the multijunction cells, are packaged in a small, inexpensive receiver at each mirror focus. Optics in the receiver apportion the intensely focused sunlight equally to many cells, for high optical efficiency and simplified manufacture. Heat is removed by recirculated liquid. The tracker carries eight 2.7 m2 mirrors and receivers. The CSTC DC efficiency of the individual mirror receiver units is measured at 32.5%. When used for electrical generation alone, the tracker system delivers an AC electrical output of 6.27 kW to the grid, referenced to a solar flux of 1 kW/m2 DNI and 20°C ambient temperature, corresponding to a total CSOC system efficiency of 29.1%, matching the best grid-connected system efficiency reported for any CPV system4. When used to generate also a thermal output of 9 kW at 64...