May 19, 2016 Christophe Image published in: Solar Thermal Energy Image available in: 350 x 305 / 150 x 150 / 300 x 261 / 350 x 305 / 350 x 305 / 350 x 305 / 350 x 305 / 50 x 44 / 150 x 131 / 250 x 218