Design and Evaluation of a III–V/Si Partial CPV Module for Maximization of Power Generation per Unit Module Area

This paper describes the design and evaluation of a III–V/Si partial concentrator photovoltaic (CPV) module with a stacked structure comprising a highly transparent CPV module and a Si cell, which aims to maximize the power generation from global normal irradiation (GNI) by harvesting not only direct, but diffuse sunlight as well. The module structure was designed by considering the optical and heat transfer characteristics, and its performance was evaluated by outdoor and indoor tests using a prototype submodule with a geometrical concentration ratio of 100×. The submodule achieves diffuse sunlight transmission of over 80%, thus generating more power from diffuse sunlight. Under clear-sky condition, the submodule with a single-sided Si cell exhibits the maximum GNI-based module efficiency of 30.7%. The submodule with a bifacial Si cell further improves the power generation and tolerance to tracking error angle for various sunlight conditions.