The invention relates to a 
heat pipe photovoltaic hot water composite 
system combined with a thermoelectric plate. The 
system comprises a whole-plate photovoltaic hot water module, a 
semiconductor double-layer heat exchange header, a photovoltaic and 
electric power control system and a water tank. The double-layer heat exchange header comprises two 
layers, i.e., a direct heat exchange layer and asemiconductor heating layer. On a clear day, circulating water flows through the direct heat exchange layer and the 
semiconductor heating layer, hot water is produced, the temperature of a photovoltaic 
cell is reduced and the 
photoelectric conversion efficiency is increased. On a somber day, the circulating water only flows through the 
semiconductor heating layer; the thermoelectric plate works; the 
water temperature is obviously raised by the 
heat pump effect of the thermoelectric plate; compared with the output of the hot water of a common PV (photovoltaic) / T (temperature) 
system, the output of the hot water is greatly increased; the temperature of the photovoltaic 
cell is lower and the 
photoelectric conversion efficiency is higher. The invention has the characteristic that the 
heat pipe photovoltaic hot water composite system can be miniaturized. The relationship between 
electric power and the output of the hot water can be regulated according to the weather and the requirement. The utilizing efficiency and the quality of 
solar energy are improved. Meanwhile, the dependence on an external power supply is reduced and the application range of the system is enlarged.