The MaReCo (Maximum Reflector Collector) is a specially designed collector that has been developed within the frames of a Swedish R&D-program concerning solar heat. The MaReCo is a stationary reflector collector adapted for Swedish conditions. With the purpose of reducing the collector costs a MaReCo-module was built in EPS (Expanded PolyStyrene). One advantage with this material is that it is easy to handle. One disadvantage is that it is sensitive for exposure of temperatures over 90oC duringlong periods. This is a temperature that is easily reached in a collector under stagnation. The purpose of this project has been to evaluate a prototype of the EPS-MaReCo. The prototype was placed at Vattenfall’s laboratory in Älvkarleby. Stagnation temperatures and energy output has been studied for both a reflector made of anodized aluminium foil and for a relector made of laminated aluminium foil: The highest absorber temperature that was reached during stagnation a sunny day was recorded to 238oC and the highest reflector temperature was 83oC. The measurements indicates that the collector prototype can handle stagnation. This conclusion is also confirmed with a visual analysis of collector module after the temperature measurements. The measurements also showed that there is no risk of too high temperatures being during normal operation. The performance evaluation was done according to the principle of dynamic testing. For the anodized reflector optical efficiencies of 0.59 and0.38 were determined for direct and diffuse radiation respectively. The heat loss factor was 1.60 W/m2,K. The same values for the laminated AL-reflector was 0.51, 0.38 and 1.22. With the simulating program Minsun, the yearly energy output was estimated to be 371 /323 / 246 kWh/m2 for the anodized reflector and 351 / 288 / 242 for the laminated at the operating temperatures 20 / 50 / 75oC