This paper describes fabrication and characterization of a solar simulator which utilizes light emitting diode (LED) as a lighting source. A solar cell powered by the LED simulator with 0.9 sun exhibited about 80% of the output power generated by the conventional Xenon lamp simulator with 1 sun. Measured temperatures for the surface of lens and fin of heat sink were in good agreement with the calculated values. Detailed thermal performance of the LED lighting was projected using a computational fluid dynamics (CFD) method for the various design parameters such as layout of the LED package and number of fins of the heat sink. It was demonstrated that the junction temperature of the LED module can be significantly decreased by optimization of the parameters. (C) 2010 Elsevier B. V. All rights reserved.