Heat pump: WWF study shows when the investment is really worth it

Heat pump at a house in Lower Saxony

In the long term, consumers can save money by switching to a heat pump – at least in comparison to a new gas heating system. This is according to a study on behalf of the nature conservation organization WWF. However, how quickly the investment pays off depends on factors such as time of purchase and household income.

A heat pump is initially more expensive to buy than a gas thermal, but according to the investigation heats cheaper and is subsidized by the state because of its climate friendliness. The level of support depends on household income and is expected to fall over the next few years. According to the calculation of the consulting company Prognos AG, the heat pump is particularly worthwhile in combination with photovoltaic systems on its own roof.

Since 21 July 2026, new funding requirements apply: The installation of a new, climate-friendly heating system is supported with up to 80 percent of the investment costs. Basic support is 30%. However, a maximum of 28,000 euros in investment costs will be subsidized. This maximum amount of funding falls by EUR 750 every six months.

The so-called climatic speed bonus also decreases over time, by four percent every six months: it is available when replacing old oil heaters or 20-year-old gas heaters and is currently 16 percent. In addition, there is an income bonus of up to 40 percent, depending on the income level.

If the air-to-water heat pump considered in the study is installed in the current year, receives the maximum subsidy rate and has a photovoltaic system, the additional costs are already compensated by the purchase after four years.

The study authors expect a single-family example house with comparatively poor energy efficiency of class F. In this category, therefore, 13 percent of the stock, seven percent perform worse. If installed in October 2026, you would save between 4303 and 15.729 euros over 15 years. If installed in August 2028, the savings would fall to an amount between 1042 and 11,042 euros. The savings depend on the level of production and on whether you have a solar system.

In the worst case, which the experts have calculated – without income bonus and without photovoltaics – the higher acquisition costs for the heat pump compared to gas heating would only compensate after 16 years. Since the investigation works with a model, homeowners should seek advice for their individual case, the WWF recommends.

The WWF requires politicians to receive the subsidies in the long term and not to melt them down as planned. “Whoever acts climate-friendly today also acts economically reasonable,” argues the organization. This also helped to detach Germany from energy imports from politically unstable regions.

Other studies have also identified cost benefits from heat pumps. According to a study by the Institute of German Economics (IW) in Cologne, the annual heating costs of a new gas heating system could almost double by 2040. The installation of a heat pump, on the other hand, would significantly reduce the cost risk in the coming years.