Optical and Thermal Analysis for Immersed Cooling of Photovoltaic Cells in a Highly Concentrated Beam

Concentrated solar radiation can be utilized to generate electrical power from photovoltaic cells, but it increases the photovoltaic cell temperature. This can lead to a degradation of the cell efficiency and too high of a temperature can damage the cell integrity. This is particularly important in dish and tower systems where a maximum uniform flux may be difficult to achieve. While a variety of approaches have been used to the keep the cells cool, most are based upon removal of heat from the back (opposite to the incident flux) of the cell. This paper reports on an immersion cooling technique for the cells, where a coolant is circulated over the complete cell including the front surface. An analysis is given where the cells are placed in a cylindrical glass tube where a liquid is circulated. The impacts of the various thermal processes that result from this approach are described here. A comparison is made to limited experimental data.