18 May 2017
Energy system consisting of combined ground-air source heat pump, PV system and seasonal ground storage for energy passive family house has been developed and analysed by computer simulation. The heat pump is equipped with a desuperheater to prepare hot water and variable speed compressor to adapt power to PV system production. Heat pump during summer operation transforms the ambient heat to charge the ground seasonal storage with use of the PV electricity only. Winter operation relies on the heat stored under the house and low grid electricity consumption. The simulation analysis have shown the significant decrease of the grid electricity needs for the house (system SPF increased from 2.9 for reference borehole system to 4.7) and increase in usability of local PV electricity production for energy supply (space heating, hot water) in the house. In total, 80 % of energy supply for the house is renewable energy and specific non-renewable primary energy need of the house is 22 kWh/m2.a (for space heating, hot water and auxiliary energy).