A passive thermal regulation technique with heat spreaders in conjunction with cotton wicks is developed for controlling the temperature of PV module during its operation. Experiments were conducted with the developed technique in the location of Tiruchirappalli (78.6 degrees E & 10.8 degrees N), Tamil Nadu, India with flat 25 Wp PV module and its viability was confirmed. The thermal and electrical performances of thermally regulated flat PV module were also compared with the results of flat PV module without cooling system. The PV module temperature was reduced by 12% while the electrical yield is increased by 14% with the help of the developed cooling system. Basic energy balance equation applicable for PV module was used to evaluate the thermal loss coefficient which was found to increase due to fin effect of heat spreader and evaporative cooling in moist cotton wicks. (C) 2015 Elsevier Ltd. All rights reserved.