Electricity Generation Performance Test of Bare and Cooled Photovoltaic Panels

Abstract

Electric generation using solar photovoltaic (PV) panels is promising for most locations because solar energy is abundant, clean and inexhaustible. However, the solar electricity generation ability of solar PV drops significantly below the nominal efficiency values as a result of higher operating temperatures, particularly in hot locations. The drop in efficiency of solar panels can be enhanced by convectively cooling solar panel surface. This paper reports the comparative electric generation performances of two identical PV panels of electric power ratings of 60 W with efficiency of 12% and photon absorption area of 0.945 m × 0.55 m. The tests were conducted by exposing both panels to the sun in parallel, one panel bare (non-cooled) and the other being cooled for three cases of cooling arrangements: continuous water cooling, intermittent water cooling, or continuous air cooling.  The electric generation performance was determined in terms of electric power output and efficiency after measuring surface temperatures, voltages, and currents of both solar panels from 9 am to 3 pm. For the bare PV panel, the average surface temperature, current, voltage, power, and efficiency over the test period were found to be 46.0^oC, 2.5 A, 18.2 V, 30.6 W, and 7.96%  for bare panel and 34.8^oC, 2.76 A, 19.2 V, 35.81 W and 9.69%  for panel cooled by water continuously. 17.02 & 21.73% day average increment of power and efficiency was attained due to cooling. These transient engineering performance data are needed for the sizing and economic viability study of PV plants in Adama City.