The EC-funded Integrated Project PERFORMANCE1 completed in December 2009 included a sub-project on the Traceable Performance Measurements of PV Devices devoted to improving the comparability of PV module power measurements between European test laboratories. The aim of the research work was to fill existing gaps of knowledge for defining specific measurement procedures for various PV technologies, to translate research results into best practice guidelines for PV industry and to provide input for standardisation working groups. To this end, various round-robin tests were conducted among test laboratories covering the range of commercially available crystalline silicon and thin-film PV modules. This paper presents the final results of our research work. It focuses on the progress achieved for PV module output power characterisation, but also sketches measurement problems remaining to be solved.JRC.DDG.F.8-Renewable Energy (Ispra