SolarPower Europe says in a new report that households in Germany, Spain and Italy can more than triple their savings by combining solar power with heat pumps. It says this combination helped families save between 62 and 84 percent on their annual energy bills in 2022.
“The solar installation complements the household’s heat pumps and fulfills a significant part of its electricity needs. The savings of the two technologies together are then greater than for either of the individual technologies,” the report says.
The industry body modeled three scenarios for medium-sized households in Germany, Spain and Italy during the energy crisis in 2022. A “PV only” scenario, a “heat pump only” scenario and a “PV plus heat pump” combination scenario that also includes a buffer – a hot water storage tank. The savings are compared to the price an average household would pay by getting all its electricity from the grid and using a gas boiler for heating.
The power of the photovoltaic system was assumed to be 8 kW in Germany and 7 kW in Spain and Italy. The Air Heat Pump was modeled for three countries with an output of 7 kW, 3 kW and 4 kW. In Germany, the volume of the storage tank was set to 800 liters and in Spain and Italy to 400 liters.
The heat demand for space and water heating was modeled as 12,000 kWh to 20,000 kWh for the existing building stock and with a gas boiler with 85% efficiency. The annual electricity demand of an average family home was assumed to be 4,000 to 4,500 kWh, and the prices of gas and electricity for the year 2022 were set according to the household energy price index.
“All relevant support measures for average family homes are included,” SolarPower Europe said, noting that this includes gas VAT cuts in all three countries. Savings from feeding electricity back into the grid are also included in the production of solar electricity.
The results show that Italian households saved the most by using a PV heat pump combination at €3,766 ($3,984), which is said to be due to the high cost of electricity in Italy. Germany with savings of 3,614 euros and Spain with 2,831 euros.
“The decrease in savings in Spain reflects measures taken by the Iberian market to lower wholesale electricity prices,” said SolarPower Europe.
The combination of both technologies reduced energy bills by 62% in Germany, 83% in Italy and 84% in Spain compared to a scenario where households obtained all electricity from the grid and used gas for heating.
In the “heat pump only” scenario, Germany’s savings were 1,884 euros, Spain’s 958 euros and Italy’s 506 euros. In the “PV only scenario”, Italy had savings of 2,935 euros, Spain 1,352 euros and Germany 1,263 euros.
The study also shows that solar electricity and heat pumps work together effectively all year round if the buffer storage is also installed. According to SPE, solar power can cover 36% of the heat pump’s total electricity needs in Germany in a cold year with low solar power. Spain and Italy, which rained sun, offer the best results. Even in a cold year, when the PV output is low, solar energy covers 59% of the heat pump demand in Spain and 50% in Italy.
The SPE concludes the report with five policy recommendations to reduce the payback period of a PV heat pump combination from the current claimed approximately 20 years to a much more attractive 10 years. These include increasing investment support for combined investments, offering low-interest loans and promoting collective own consumption.
“The best time to install solar + heat pumps was yesterday,” said Dries Acke, Policy Director of SolarPower Europe. “The next best time is now. European policy makers need to bring the benefits of gas-free homes to the wider population.