For heating our homes, fossil gas is no longer very fashionable. But when it comes to changing your system, you might wonder which solution will be the cheapest: hydrogen – not yet quite available on the market, moreover – or the heat pump?
In Europe, experiments with the injection of green hydrogen into urban fossil gas networks are underway. With the idea of decarbonizing the heating of our homes – and at the same time, to free ourselves from Russian fossil gas. But researchers at the Swiss Federal Institute of Technology in Zürich (Switzerland) show today that a low-carbon transition that limits costs without causing excessive environmental damage is not “possible only through the electrification of heating systems via heat pumps ».
A green hydrogen heating system would indeed turn out to be approximately “ two to three times more expensivethan a system based on said heat pumps. The fault, in particular, of the costs of manufacturing and storing hydrogen and the construction, essential in this case, of additional renewable energy infrastructure.
The researchers point out that they did not just question the economic model. They also asked the environmental question. By allocating to each scenario explored a share of the remaining carbon budget, but also a share of the fresh water budget, land use and other global resources. To ensure that the scenario remains well constrained in the famous“planetary boundaries”.
Hydrogen that is too expensive and not sustainable enough
Remember that only 0.4% of the hydrogen produced in the world today is green. Understand, produced from low-carbon electricity. It is still very expensive to manufacture. If its prices fall, it could first interest other sectors that want to decarbonise, such as heavy industry. And the researchers point out that, anyway, hydrogen is not the most efficient in providing the energy needed for our homes. It would take five to six times more wind and solar capacity for our hydrogen heating than to provide the same service using heat pumps. Pushing planetary boundaries beyond any scenario in which green hydrogen plays a significant role.
The researchers also warn that blue hydrogen – that produced from fossil gas, but whose CO2 emissions are captured2 in the process — shouldn’t be considered sustainable either. Especially since with fossil gas prices expected to remain high for a while, it could become less economical. In Europe, therefore, researchers confirm the recommendation of the International Energy Agency (IEA) to favor heating by heat pump. Even if they remind that the fight against climate change will require a range of technologies optimized for local conditions.