Innovative solar photovoltaic and thermoelectric power generator for a recirculating aquaculture system

Abstract

Solar Photovoltaic power generation is fast gaining popularity in Kenya. However, the effects of high cell temperatures continue to be a major hindrance to their efficiency especially for standalone systems. Water can be used for cooling when combined with thermoelectric generators (TEG) in areas where it is available achieving double gains. Kisumu Nyalenda, in Kenya is one such site where weather and irradiance data have been collected for the design of a PV+TEG power generation system. In this paper, a 3-tier study is conducted to evaluate TEG power, voltage, current and temperature distribution and the overall performance of the hybrid system. Numerical simulations are conducted on Matlab Simulink platform model based on a medium temperature gradient (10 0 C - 100 0 C) category TEG. Bench study setups are done replicating the weather and irradiation conditions of a Recirculation Aquaculture System (RAS) in Nyalenda Kisumu. The TEG bench results are then used to guide the design of the autonomous PV+TEG power generation system. Obtained results confirm that by accurately modelling the TEG and matching its internal resistance to the load, maximum power can be achieved. It is further confirmed that using series-parallel connection of TEGs stack under PV modules operating at temperature gradients varying between 5 0 C to 35 0 C, a 20 kWp PV system gains an extra 15.7% from TEG array with a further 1.05% power gain from PV module temperature reduction.