Oxford – Decarbonizing German's heating sector

The decarbonization of Germany's residential and commercial heating sectors is crucial for the country to achieve its net zero targets by 2045. Currently, a significant portion of buildings are heated by oil or gas, making it imperative to find alternative options. Low-temperature heat, such as space heating and warm water, can be provided by heat pumps and waste heat via district heating. Three major approaches to achieve zero CO2 emissions at the point of heating are heat pumps, district heating, and switching gas supply from methane to hydrogen. However, there are challenges in providing CO2-free energy and determining the best mix for the millions of buildings currently using oil and gas. Heat pumps require CO2-free power generation, which can come from renewables combined with power storage or thermal power with carbon capture and storage. District heating offers various options such as geothermal, large heat pumps, waste heat utilization, and combined heat and power with carbon capture and storage. The transition to green hydrogen from methane is not feasible within the given timeframe, so blue hydrogen from autothermal reformers is expected to dominate. Switching all buildings to heat pumps based on renewable power alone is unlikely to be feasible by 2045 due to slow renewable and heat pump roll-out, lack of storage solutions, and limited capacity in the power system. A combination of heat pumps, district heating, and methane-to-hydrogen switch for approximately 5 million buildings each is a more realistic approach. Early actions should focus on CO2 collection, CO2 capture in power plants, and decisions at the municipal level regarding technology choices and the expansion of district heating pipelines. The German government's recent legislation favors renewables and heat pumps over a balanced approach that includes carbon capture and storage. To meet the net zero target by 2045, a wider discussion is needed to consider hybrid solutions rather than relying exclusively on specific technologies that may not be sufficient. Early investment supported by Germany's strong credit rating is crucial for the development of CO2-free technology and infrastructure.