Using the concentrating and tracking photovoltaics generation technology, the area of photovoltaic cells is only one-fifth of the traditional one if both generate same power output, and therefore the cost of photovoltaic power generation is greatly reduced. The concentrating solar cells produced with the special construction and lamination technique have the functions of heat exchanging and temperature controlling, which prevent the solar panel from over-temperature caused by the concentrating light and the crystal silicon cell pieces will always work under 60°C, and hence the photoelectric conversion efficiency increase. The rest solar energy that cannot be converted into electrical energy by the concentrating solar cells is absorbed by water flowing through it. The flat-plate collector reheat the water flowed from the concentrating solar cells’ heat exchanger and the additional product, hot water, whose temperature is over 80°C, is got. Hence, the total efficiency of photovoltaic & thermal conversion is more than 55%. The solar photovoltaic & thermal system can high efficiently, but low costly and practicably, utilize the solar photovoltaic & thermal and practical.