Hybrid Perovskite-Photovoltaic and Solar-Thermal Harvesting

Single-junction photovoltaics have inherent limitations as low-energy photons below bandgap cannot generate electrical power, wasting solar energy. Here, a hybrid solar energy harvesting concept is presented. The prototype's core component consists of a semi-transparent perovskite solar module that converts high-energy solar photons into electrical power at 14.3% efficiency, while directing ≈55% of the low-energy photons below bandgap to a solar-thermal collector. The prototype can achieve an overall exergy efficiency of ≈30.0%, with exergy referring to the usefulness of transformed solar energy and its potential to do work. This high efficiency comes from 1) photovoltaic conversion, 2) low-temperature heat generation (60 °C) from photovoltaic thermalization losses, and 3) high-temperature heat generation (900 °C) from the low-energy photons in a modeled large-scale high-concentration-ratio solar concentrator. The exergy efficiency can advance to >40% if using a record-efficiency perovskite photovoltaic. Overall, this study provides a high-efficiency solution for harvesting the full solar spectrum.