A new, free-of-charge software is now available from the Siemens Industry Automation Division for calculating the best possible configuration of photovoltaic (PV) plants. The program, Sinvert Select V2.2, can be downloaded from the Internet at www.siemens.com/sinvert-select. It enables the planner to evaluate in advance the cost-effectiveness of PV plants from 10 kW up to the megawatt range. A comparison of possible configurations shows the energy yield of the various plant arrangements. The software is available in German, English, French, Italian and Spanish, and has been specially designed for Sinvert PV inverters.