Comparison of Different Solar Collector Configurations to Assist an Air Source Heat Pump for Supplying Domestic Hot Water

Renewable energy is a key for sustainable development all over the world and renewables used in many areas including water heating. For water heating, among many options, electrical and solar energy can be used to assist heat pumps. This study explores usage of photovoltaic and thermal collectors to assist heat pump for supplying DHW in an efficient way. Firstly, experimental tests have been performed in a climatic room and using the experimental results, the simulation model developed in TRNSYS software has been validated. Four different scenarios were created based on collector type and number supporting the DHW heat pump system and were compared with each other in terms of energy efficiency. For systems supported by heat pump and maximum of three collectors, the best options saved 564.71 kWh-e for one thermal collector and 1051.77 kWh-e for two collectors, one thermal and one photovoltaic. When the heat pump is supported by three collectors, the configuration with one thermal and two photovoltaic collectors, which is the best option, produces 107.39 kWh-e more energy than the energy consumed. Consequently, this study clearly illustrated that the right combination of thermal and photovoltaic collectors significantly reduces the energy consumption of DHW solar heat pump systems.