A new study from consulting firm Prognos, commissioned by the German Geothermal Association (BVG), the Bavarian Geothermal Association, and the German Heat Pump Association (BWP), finds that geothermal heat pumps are the most cost competitive solution for heating single-family and multi-family homes.
Using the examples of an average single-family home and an apartment building with eight units, the study compares the annuity-based total annual costs of a gas boiler in single-family and multi-family homes with those of an air-source heat pump and a ground-source heat pump. The results show that while the gas boiler may be on par with the two heat pump types in the first few years, the differences quickly widen due to rising gas prices, an increasing share of biomethane, and rising CO2 prices. The study clearly demonstrates that, under current conditions, the heat pump is the significantly more economical option.
"Therefore, it is particularly worthwhile for owners of single-family and multi-family homes with a long-term ownership perspective to carefully consider the options when selecting a heat pump system," advised Dr. Martin Sabel, Managing Director of the German Heat Pump Association.
Comparing geothermal heat pumps to air-to-water heat pumps, the study finds that geothermal heat pumps incur lower annualised costs, with savings of 8% over a period of 20 years.
"Over the entire lifespan, the technology has a major advantage – those who invest in geothermal energy are acting with foresight and putting their heat supply on a secure footing," said Gregor Dilger, Managing Director of the German Geothermal Association (Bundesverband Geothermie e.V.).
The report also considers that the lifespan of geothermal probes is significantly longer than that of the actual heating systems. While gas and heat pump heating systems are factored in with a lifespan of 18 to 20 years, the lifespan of geothermal probes is estimated at at least 60 years, possibly more.
"The fact that geothermal-powered heat pumps score points for cost-effectiveness, alongside their environmental friendliness and long lifespan of several decades, is another reason to rely on this technology," said Christoph Knepel, Chairman of the Bavarian Geothermal Association.
With recent geopolitical developments bringing to the fore the issue of dependence on global fossil fuels, the independence offered by a domestic, renewable heat supply is a strong argument for decarbonising the building sector, says the Association. Geothermal energy should play a crucial role in this in the future.