Photovoltaic thermal hybrid solar collector

Photovoltaic thermal hybrid solar collectors, also known as hybrid PV/T (PVT) or solar cogeneration systems, are power generation technologies that convert solar radiation into usable thermal and electrical energy. Such systems combine a solar cell, which converts sunlight into electricity, with a solar thermal collector, which captures the remaining energy and removes waste heat from the PV module. These technologies can be more energy efficient overall than solar photovoltaic (PV) or solar thermal alone. Photovoltaic thermal hybrid solar collectors, also known as hybrid PV/T (PVT) or solar cogeneration systems, are power generation technologies that convert solar radiation into usable thermal and electrical energy. Such systems combine a solar cell, which converts sunlight into electricity, with a solar thermal collector, which captures the remaining energy and removes waste heat from the PV module. These technologies can be more energy efficient overall than solar photovoltaic (PV) or solar thermal alone. Significant research has gone into developing a diverse range of PV/T technologies since the 1970s.. While many collector types have been developed for small-scale residential or specific process use, powerful and highly-efficient systems for industrial and utility-scale applications are also beginning to enter the market. Collectors co-generating up to 250kW electricity plus 400kW heat, and operating with 80% conversion efficiency, are commercially available as of 2017. Photovoltaic cells suffer from a drop in efficiency with the rise in temperature due to increased resistance. PV/T systems are engineered to actively capture and carry heat away from the PV cells, thereby cooling the cells and thus improving their efficiency by lowering resistance. Cell lifetimes also improve at lower temperatures, and the thermal capture can minimize the urban heat island contribution from the generator. This is an effective method to maximize total system efficiency and reliability, but causes the thermal component to under-perform as compared to that achievable with a pure solar thermal collector. That is to say, the maximum operating temperatures for most PV/T system are limited to less than the maximum cell temperature (typically below 100°C). Nevertheless, two or more units of heat energy are still generated for each unit of electrical energy, depending on cell efficiency and system design.