Experimental analysis and performance evaluation of a tandem photovoltaic-thermoelectric hybrid system

Although photovoltaics have been established as the dominant technology considering the field of solar energy conversion systems, issues regarding their relatively low efficiency still remain practically unsolved. Very recently, the possibility of combining photovoltaic (PV) cells and thermoelectric generators (TEGs) in hybrid systems, as a means of improving the overall conversion efficiency, has attracted particular attention. In this paper, the performance of a tandem PV-TEG hybrid, employing poly-Si as well as dye-sensitized solar cells, has been examined experimentally. Thermoelectric devices of different thermoelement geometry have been tested in order to identify the corresponding performance effect. In addition, the outcomes of the experimental process have been exploited in order to evaluate the performance of the system under real operating conditions. The analysis conducted indicates that the utilization of TEGs with shorter thermoelements results in enhanced power output levels, when conditions of actual operation are considered. Moreover, although improved power output is obtained by the setup employing the polycrystalline cell, dye-sensitized technology could become particularly attractive when the incorporation of solar cells in PV-TEG hybrids operating under conditions of elevated temperature is examined.