Highly-integrated Hybrid Micro-Concentrating Photovoltaics

Recent development of aintegrated micro-scale hybrid PV/CPV approach is presented. The Wafer Integrated Micro-scale PV approach (WPV) seamlessly integrates multijunction micro-cells with a multi-functional silicon platform that provides optical micro-concentration, hybrid photovoltaic, and mechanical micro-assembly. The development of the firstgeneration prototype module based on the WPV concept is described. Initial outdoor module characterization results will also be discussed. The WPV approach is experimentally shown to achieve over 100% improvement on the concentration-acceptance-angle product (CAP), using the wafer-embedded non-imaging micro-concentrating elements. The wafer-embedded-features lead to significantly reduced module material and fabrication costs, sufficient angular tolerance for low-cost trackers, and an ultra-compact optical architecture compatible with commercial flat panel infrastructures. The performance of the PV/CPV hybrid architecture is projected to illustrate its potential for cost-effective collection of both direct and diffuse sunlight, thereby extending the geographic and market domains for cost-effective PV system deployment. Our outdoor testing results on diffuse light collector in Cambridge, MA, USA indicate strong forward scattering effect of the diffuse light, which consequently can be utilized to design efficient diffuse concentrators to further reduce the cost of the Si cell. Leveraging low-cost micro-fabrication and high-level integration techniques, the micro-scale PV/CPV hybrid approach effectively combines the high performance of multijunction solar cells and the low costs of flat-plate Si PV systems.