Dish/photovoltaic cavity converter (PVCC) system for ultimate solar-to-electricty conversion efficiency-general concept and first performance predictions

In this paper, United Innovations, Inc. (UI²) presents the results of extensive analytical studies involving a radically new concentrator system based on the photovoltaic cavity converter (PVCC) concept under development. The objective of this project is to achieve an unprecedented solar-to-electricity conversion efficiency of 50% (half the sun) that will substantially reduce the cost of solar electricity. This R&D effort is supported by DOE/NREL with the purpose of demonstrating a 1.5 kW unit in the near term. The system considered is a dish/PVCC combination consisting of a primary concentrator, a secondary flux booster and a PVCC. Trapped flux inside the cavity undergoes spectral splitting via selective reflection/transmission by special Rugate filters. A four bandgap array inside the cavity consisting of four complementing III-V single-junction cell types achieves a collective conversion efficiency of 48.32% at 100 suns.