Recent work, such as the H21 Leeds City Gate study, has shown that conversion of UK gas distribution networks is feasible and could help to decarbonise the heating of buildings. A hydrogen-ready boiler is intended to provide a like-for-like replacement for an existing natural gas boiler. Manufacturers such as Baxi and Worcester Bosch are currently working on prototypes of hydrogen-ready boilers which will work with natural gas but can be switched to 100% hydrogen when required but they are not currently available to buy.
The major advantage of a hydrogen-ready boiler is that it can continue to use natural gas until hydrogen gas is available. This will allow the whole country to transition to the low carbon alternative in a strategic way and with almost no disruption to home heating.
The main benefits of hydrogen boilers are that they are highly efficient (1kg of hydrogen can produce as much energy as 2.8kg of natural gas). There would be no carbon emissions from hydrogen boilers (they only produce water vapour and heat) and Hydrogen can be used in the existing gas grid infrastructure.
About 35% of the existing gas network in Britain has already been converted to PVC lined pipes which are ideal for hydrogen. Clearly the conversion of the remaining network has to be completed before the whole system can convert to hydrogen. In the meantime manufacturers like Worcester Bosch are well on the way to developing hydrogen ready gas fired boilers which will allow conversion to hydrogen in a seamless way. The government has yet to commit to converting the full gas network to hydrogen. A recent report by the Fraser Nash Consultancy estimated that it could take up to 16 years to complete the total conversion to Hydrogen with the current available workforce.
However, according to an announcement by the House of Commons Science & Technology Committee on the 16th December 2022 "there are significant infrastructure challenges with converting our energy networks to use hydrogen and uncertainty as to when low carbon hydrogen can be produced at scale at an economical cost. Future decisions on the role of Hydrogen must increasingly be practical, taking into account what is technically and economically achievable". The Committee is unconvinced that hydrogen will be able to play a significant role in heating homes by 2026 when the government has said that it could start mandating hydrogen boilers in domestic homes.
Hydrogen Fuel Cells – the future?
A hydrogen fuel cell breaks down hydrogen into its different parts to generate electricity. As a by-product of this process, heat is also produced which can be used to heat the home. A fuel cell is therefore potentially a source of both heat and power. Combined heat and power boilers feature fuel cells that generate electricity while at the same time creating heat that can be harnessed to provide hot water and central heating.