Comparative Study between a Heat Pump and an Electrical Resistance as Energy Support for a Solar Water Heater
Heating water using solar energy can significantly reduce fossil fuel consumption. However, during the lack of sunlight it is necessary an alternative energy source to supplement or substitute the solar energy. To provide this additional energy, electrical resistances are among the most common devices used. In this work it is presented an experimental analysis of an alternative system to support solar water heating with a better cost-benefit ratio than that of the electrical resistance. For this purpose, a heat pump was designed, constructed and experimentally evaluated as supplementary heating source. To improve the system’s performance, a static evaporator was used as a substitute for the conventional evaporator. The mean coefficient of performance (COP) for the heat pump was 2.15. The same tests were performed utilizing an electrical resistance as heating source and the results obtained in this case were compared with the results obtained using the heat pump. The moderate cost of acquisition and installation of the heat pump allowed an investment return between 2.5 and 3.6 years, depending on the city in which the system is installed. Considering that the equipment has an estimated lifespan of 15 years, the internal rate of return varies from 24.5 to 37.9%, which is attractive for investment.
Dashnor Hoxha, Francisco E. Rivera and Ian McAndrew
R.V.M. Reis et al., "Comparative Study between a Heat Pump and an Electrical Resistance as Energy Support for a Solar Water Heater", Advanced Materials Research, Vol. 1016, pp. 748-752, 2014