Burning question: why hydrogen boilers are not the answer

Published on September 13, 2023

Fossil fuels are the predominant energy source for space and water heating in residential buildings, accounting for 12% of greenhouse gas (GHG) emissions in the EU. This has a dramatic impact on the climate.

Some trade associations and appliance manufacturers endorse hydrogen as a viable pathway to decarbonise the built environment. But, as this paper will go on to show, hydrogen heating in residential buildings cannot deliver on such a promise. Hydrogen – whether blended with gas, or pure – should not be used to heat households.

A recent study performed by Eunomia outlined a number of techncial and safety obstacles that still need to be overcome for hydrogen boilers to be deployed in homes. In addition to putting lower energy efficiency appliances (resulting in higher heating bills) on the market, there are serious concerns over safety and maintenance.

Other mature alternatives, such as electric heat pumps, offer dramatically more efficient (and realistic) solutions for the large-scale transition that is needed to decarbonise the built environment. For this reason, studies have shown that residential heating has the lowest priority of all hydrogen applications. This has been echoed by the Joint Research Centre of the European Commission, which stated that for heating and cooling, hydrogen in the built environment has no benefit at all, even in its renewable form.

Fossil fuels play a big role in the generation of hydrogen . Only a miniscule 0.04% of hydrogen is produced using electricity. And even when it is, it is still not the most efficient option. Electrolysis supplied with renewable electricity generats hydrogen with the lowest life-cycle climate impact. But around 30% of energy is lost in the transformation process. Renewable hydrogen is scarce, so we must be strategic about its end use.

Renewable hydrogen should be channelled to those sectors that are ‘hard-to-abate’ (e.g., heavy industry, long-haul aviation, shipping, and chemicals), where electrification is still not economically or technically feasible. Channelling hydrogen to other sectors, like residential heating, would mean wasting this valuable resource. More efficient and climate-friendly solutions exist and should be used, such as electric heat pumps