2013年万份教师招聘试题资料合集免费下载：http:/ Solar Energy Systems:More Heat,More Light Solar photovoltaic thermal energy systems, or PVTs, generate both heat and electricity, but until now they havent been very good at the heat-generating part compared to a stand-alone solar thermal collector. Thats because they operate at low temperatures to cool crystalline silicon solar cells, which lets the silicon generate more electricity
