Development of a composite PVT panel with PCM embodiment, TEG modules, flat-plate solar collector, and thermally pulsing heat pipes

Abstract

An integrated, multi-layered, composite photovoltaic thermal (PVT) module consisting of a multitude of stand-alone mini PVT cartridges was developed and a prototype was tested. Individual PVT cartridges consist of several sandwiched layers with photovoltaic cells, TEG units, packed-bed PCM layer for thermal storage, and thermally controlled heat pipes with dynamic control. These cartridges may be easily removed from the master PVT casing and re-installed for repair, inspection, and replacements. When cartridges are installed, the composite PVT module is completed by adding a flat-plate collector layer on the top. An internal array of pulse-control heat pipes maintains the total exergy output (power and heat) at a maximum by adjusting the heat flux. This PVT panel design eliminates the need for external thermal storage, pumping of the PVT coolant, and associated parasitic losses. PVT technology is made more energetically and exergetically rational as an economic asset for decarbonizing the environment. In such a configuration, it represents the solar equivalent of a conventional cogeneration system with a bottoming cycle. This paper summarizes the technological evolution of the new composite PVT system and provides examples of its use. Pilot-scale tests have shown that the Rational Exergy Management Model efficiency is about 25% more than a conventional PVT system and the total net electrical power output per unit solar insolation area is more than 30%. Total exergy output (power and heat) is twice as much as a conventional PVT unit in a typical summer month. The results obtained are discussed with further evolutionary recommendations. The importance of exergy-levelized unit panel cost is put forth to provide a basis for the fundamental procedure for a dedicated, well-accepted, and stand-alone PVT test method for the rating of system performance.