RENEWABLE ENERGY

An experimental system was developed and tested in order to investigate the energetic performance of a solar photovoltaic system (PV) assisted earth-to-air heat exchanger (underground air tunnel) that is used for greenhouse cooling at the Solar Energy Institute, Ege University, Izmir, Turkey. Average value of temperature differences between inlet and outlet of earth-to-air heat exchanger (EAHE) was observed 8.29 degrees C at experimental measurements. The average heat discharge rate (cooling load) was realized as 5.02 kW by using 0.7 kW fan. System was operated about 11 h/day. As a result, total electricity energy consumption of the system was measured to be 8.10 kWh and 34.55% of this energy demand was provided from photovoltaic cells. Furthermore, 65.45% of the electricity energy demand was provided from grid connection. Results are discussed and interpreted in the paper for various performance metrics. (C) 2012 Elsevier Ltd. All rights reserved