A new economical large-scale multiple-lamp solar simulator was designed and constructed to provide a test platform for the simulation of solar radiation at the earth's surface. The light source and fabrication of the simulator is described. Measurement of the irradiance indicates that the multiple-lamp simulator conforms to Class B of the ASTM (American Society for Testing and Materials) and IEC (International Electrotechnical Commission) standard in regard to spectrum match, irradiance uniformity and stability. Without altering the spectral distribution, the average irradiance on the target area can be adjusted between 150 and 1100 W/m(2) by varying the number of lamps and/or the lamp-to-area distance. Diurnal irradiance variation trends could also be simulated through suitable control. The irradiation characteristics of the solar simulator under a variety of operating conditions were investigated using an optical simulation model, which was experimentally validated and provided physical experiments with reference data with savings in both time and cost. To enlarge the effective irradiated area, two large mirror-like stainless steel plates was mounted on both of the long sides of the solar simulator. The optimal reflection angle was determined by means of optical simulation. The radiation characteristics of simulator are improved and the optimized effectively irradiation surface is expanded up to 81.6%. (C) 2011 Elsevier Ltd. All rights reserved.