The views expressed are those of the author and do not necessarily reflect the position of FORESIGHT Climate & Energy

Hydrogen should be welcomed as a solution to heating our buildings
It might sound like a bold statement but embracing the potential of hydrogen for heating buildings is essential from both an ecological and an economic point of view. Hydrogen has served successfully as an energy carrier in municipal gas grids for decades. “Green” hydrogen, produced by renewables in a climate-neutral way, can replace natural gas, therefore contributing fundamentally to the energy transition and the decarbonised energy landscape of the future. It can be beneficial not just to industrial and non-residential environments, but to every household that has relied on gas as an energy carrier up to now. GAS MIXTURE What is particularly interesting for building operators is that hydrogen can be used as a mixture with natural gas in the existing gas grid, using existing heating technology. While heat pumps are becoming one of the most popular heating technologies for new construction, the potential of hydrogen in renovating and refurbishing the heating systems in existing buildings needs to be emphasised. The transition from using natural gas in a building’s heating system to hydrogen can be smooth. Technically, mixing natural gas with hydrogen does not pose any major issues. Heating systems with gas boilers, for instance, can cope with an admixture of 10% hydrogen without any problems. Even an admixture of up to 20% hydrogen to natural gas seems feasible in most cases. A steady increase in the proportion of hydrogen to natural gas could begin immediately. HYBRID SYSTEM The ideal setup for such a building heating network seems to be a hybrid system. Basically, this involves the use of two different energy sources. The combination of a hydrogen boiler with an electric heat pump is a good choice. The heat pump does its work whenever that makes sense, such as when the outside temperatures are within a “normal” range. Whenever it gets too cold outside, higher water temperatures are needed in the building, which in turn could make the heat pump’s work less efficient. Under these circumstances, the hydrogen boiler can take over in order to heat the building. Depending on the design of the respective heating capacity of the appliances, this results in a utilisation of the heat pump of 70-90% and an almost completely regenerative heating model, of course depending on the green share in electricity and gas production. Similarly, it might make sense to combine a hydrogen boiler with a solar thermal system. Often, investments have already been made in the infrastructure, which can be further utilised by combining it with hydrogen. STORING SURPLUS In Europe today, it is assumed that boilers will have to be able to use a mixture of natural gas and 20% hydrogen within the next five years. From 2029, it should be possible to convert gas appliances to 100% hydrogen by means of conversion kits (“H2-ready”). Using hydrogen and other green gases across Europe would save €130 billion a year in 2050, according to experts from the industry alliance Ready4H2. The existing natural gas infrastructure, which can be used immediately for injecting hydrogen, and the ease of storage and transportation, make hydrogen indispensable. SECURE FUTURE Green hydrogen is a key lever for a climate-neutral, sustainable, and secure future. As we all know, the challenge of green electricity harvested from renewable energy sources is dependent on the real-time availability of wind and solar radiation, as well as on geological, timely or seasonal aspects in general. If you want to switch to 100% green electricity, you have to provide production capacity that exceeds the maximum demand. With the help of electrolysis plants, surplus electricity can be stored in the form of hydrogen. This ideal symbiosis will guarantee a secure and continuous energy supply. Successfully tackling the energy transition will not be possible without sector coupling, which brings electricity, heating, and e-mobility together. As a result, it will be possible to make use of electricity peaks. Here, balancing via hydrogen, which can also be used to heat buildings, will be the ideal solution.

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