18 May 2017
The paper analyzes utilization of a PV system driving the heat pump of a low energy house in Warsaw during winter. Based on the demand for electricity of the considered building for summer conditions the size of the photovoltaic system has been determined. On the basis of meteorological data and technical data of PV modules the energy output for all hours of the year has been calculated. The duration of the heating season and the amount of energy that must be supplied to the heat pump in all the days of the year to keep the indoor air temperature at a constant level have been calculated. After taking into account the heat pump output, an estimation of the time of its operation for all the days of the year has been made. The share of PV energy and energy from the grid towards the total energy supplied to drive the heat pump has been determined. Two cases of PV system configurations have been considered. The first utilizes batteries for storage and all the energy produced by the PV system can be used to drive the heat pump. In the second case, the time of the heat pump operation is coupled to the time of the availability of solar radiation and the PV operation. However, operation of both systems is not coherent all the time. The impact of the PV operation on indices of energy consumption is analyzed. For the considered specific micro scale PV system coupled with a ground heat pump to supply energy for space heating in this low-energy building, the results show that reduction of primary energy consumption is not significant. However, to give a definite answer of how the PV system should be coupled to a ground heat pump to supply heat for the space heating of a low-energy building the optimization of the operation of the heating system based on technical and economic aspects should be performed.