Feasibility Study for PV Measurements at Varying Irradiances on a Large-Area Steady-State Solar Simulator

Reliable prediction of photovoltaic (PV) module performance under real operating conditions requires several steps beyond the current comparison at Standard Test Conditions (STC). The standard IEC 61853-1 establishes the requirements for power matrix measurements, which involve variation of the module’s temperature as well as of the irradiance level with respect to STC. The large-area steady-state solar simulator (LACSS) of the European Solar Test Installation (ESTI) can be used for PV device characterisation at conditions other than STC, e.g. power matrix and linearity measurements. For both cases, the irradiance level should be varied without significantly affecting the spectral content and the spatial non-uniformity (NU) on the test plane. At ESTI this can be achieved by an appropriate selection of the LACSS lamps. However, as this procedure implies a possible change in the NU, a better characterisation of the solar simulator and an automation tool for irradiance prediction were deemed necessary to increase confidence in the process. Initial comparison between predictions and measurements demonstrated satisfactory agreement typically within ±1% for irradiance distribution and NU. Also, the result of the solar simulator assessment is positive for advanced PV measurements, although care must be taken in the selection of lamp combinations and in their constant update.JRC.C.2-Energy Efficiency and Renewable