The paper analyzes utilization of a PV system driving a heat pump in the low energy house in the Polish climate during winter. Based on meteorological data and technical data for the PV modules the energy output for all hours of the year is calculated. The duration of the heating season and the quantity of energy that must be supplied to the heat pump over all the days of the year to keep the indoor air temperature at a constant level are calculated and an estimate of the time of its operation for every day of the year is made. The share of PV energy and energy from the grid towards the total energy supplied to drive the heat pump is determined. Two cases of PV systems are considered: with batteries and without (but the time of the heat pump operation coincides with the time of the availability of solar radiation). The impact of the PV operation on indices of energy consumption is analyzed according to Polish energy sector rules. The results show that reduction of primary energy consumption is not significant. However, to give a definite answer on reduction of energy consumption a study of the operation over a whole year is needed. (C) 2020 Elsevier Ltd. All rights reserved.