Photovoltaic Thermal Hybrid Solar Collectors - also known as PVT systems, are systems that convert solar energy into thermal and electrical energy. In many PVT concepts, the heat generation and its removal will takes place in different locations in the module. For an efficient yield the materials between these locations should have a high thermal conductivity. A high thermal conductivity diminishes any temperature difference between the PV cells and the heat-transporting fluid in the tubes and lowers the operating temperature of the device. A lower operating temperature promotes a higher efficiency.  The cell at the highest temperature will even limit the efficiency of a whole string of cells.  Hence the coolant circuit should be designed to keep the cell temperature uniform and relatively low.  The total heat transfer coefficient between PV cells and plate is largely determined by the conductivity of the intermediate layers.  The heat transfer performance of these materials can easily be measured with the C-Therm TCi Thermal Conductivity Analyzer.