Source (both images): European Commission, An EU Strategy on Heating and Cooling
Heating and cooling consume half of the EU's energy. Although this sector aims at being a clean and low carbon energy, 75% of the fuel it uses still comes from fossil fuels (nearly half from gas). The sector is based on a vast, European interconnected gas infrastructure which delivers the needed energy to heat homes in the EU.
If Europe wants to decarbonise heating and cooling it faces several options: Through the electrification of heating with heat pump or electric heaters or via the introduction of renewable gas such as hydrogen or biogas.
The electrification options are feasible for a number of building (new builds only and that are well insulated and where low temperature heating through the floor is possible) but the majority of the building stock today is not compatible. Moreover, the demand of heat is concentrated in winter time when renewables are less available. Additionally, a complete electrification of heat would imply that the gas grid is no longer used and becomes a stranded asset.
It is in fact smarter to consider a complementary solution (in fact much bigger than electrification): decarbonising the gas grid by blending natural gas with renewable gases like hydrogen and biogas, in the same way as we are progressively decarbonising the electricity grid. Hydrogen can make up 5 to 20% of the volume content of natural gas supply without any infrastructure modifications. Some cities and regions can even transform their gas grid into a pure hydrogen grid. This is even more interesting as pipeline transportation of hydrogen reaches almost 100% efficiency. This benefit makes hydrogen an economically attractive option when transporting renewable energy at scale and over large distances, e.g., from areas with a high potential for renewable power generation to areas with high energy demand like Europe. Therefore, there is a need to decarbonise the gas infrastructure through novel fuels and technologies.
There are three ways to decarbonise the gas grid: green and decarbonised hydrogen.
- Green hydrogen through water electrolysis using renewable electricity.
- Decarbonised hydrogen through natural gas reformation with carbon capture and storage.
- By-product hydrogen taken from an unavoidable source of hydrogen which would have been otherwise flared or ineffectively burnt for electricity generation.
The gas infrastructure decarbonisation through the introduction of high share of such hydrogen, firstly through a blending with natural gas and in the future possibly to a complete conversion to 100% hydrogen system is a reality that needs to be acknowledged and pushed for.
Additionally, this enables a greater integration of renewable energy sources and a direct reduction of greenhouse gas emissions. Furthermore, due to the increased share of intermittent renewable energy sources (wind and solar) in the European energy system, the utilisation of the vast gas infrastructure as an energy storage asset is an opportunity (the green gas being used in homes but also in gas-fired power plants (link to sectoral integration).
Hydrogen represents the optimal overall solution for long-term, carbon-free seasonal storage.
Decarbonising heating is not only about changing the fuel. It is also about improving efficiency to start immediately reducing CO2 and other emissions. The introduction of fuel cell micro combined heat and power installations at home can use natural gas today whilst being compliant with an increasing share of green hydrogen as blending now and 100% hydrogen in the future.
Industry has many options for decarbonizing low-grade heat. While heat pumps and electric resistance heating offer advantages in certain geographic locations, hydrogen is clearly advantageous when it is available as a by-product of the chemical industry or when a specific industry needs an uninterruptable power supply (as provided by a fuel cell), along with heat. As hydrogen can be combusted in hydrogen burners or be used in fuel cells, it offers a zero-emission alternative for heating.
High-grade heat - above 400°C - is harder to decarbonize. Hydrogen burners can complement electric heating to generate high-grade heat, depending on local conditions: some regions might favour industrial use of hydrogen technologies instead of electricity, given the constraints they have in the design of their energy system.
Today, industry uses hydrogen in low-grade heat applications, such as process heating and drying. In the future, industry might also use a mix of hydrogen burners and fuel cells to meet their low- and high-grade heat needs. Fuel cells have a higher efficiency than burners and simultaneously provide heat and power, but their deployment still requires significant investment. Burners, on their side, require only adjustments of existing equipment.