In 2015, the Paris Agreement set a goal to reduce global temperatures by 2°C compared to pre-industrial levels. This called for a reevaluation of fossil fuel combustion and its environmental impact.
Researchers from the Technical University of Munich conducted a comparative analysis of 13 heating systems, including gas boilers, pellet boilers, wood gasification boilers, air-to-water heat pumps, air-to-air heat pumps with photovoltaic systems, and geothermal heat pumps with ice storage and solar sensors. The study was carried out using a typical two-story German home as an example.
The scientists evaluated the economic and environmental performance of each heating system, considering installation costs, energy consumption, maintenance fees, and the CO2 emissions each system generates.
Surprisingly, the winner is a combination of an air-to-water heat pump and photovoltaic panels! Biomass heating systems, which produce heat from renewable natural materials, had the least environmental impact. In contrast, gas heating systems were found to have the highest environmental impact. Adding solar panels to an already efficient heating system reduces its environmental footprint.
According to the researchers, “electricity supply accounts for over 90% of the environmental impact” of heat pumps during their operation. Adding a system that supplies electricity from renewable energy sources significantly reduces the “environmental burden.” The wood gasification boiler also proved to be one of the most eco-efficient systems in the study.

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