Frequently Asked Questions

H21 is a suite of gas industry projects, delivering evidence to support the transition of the gas network to transport 100% hydrogen.

H21 is funded by Ofgem and led by Northern Gas Networks in partnership with Cadent, Wales and West Utilities, Scottish Gas Networks and National Grid. Specialist partners, including DNV and the Health and the Safety Executive’s Science Division, are also involved in the projects.  

To tackle climate change the UK has committed to reaching net zero emissions by 2050 and reducing emissions by 78% of 1990 levels by 2035

The gas we currently use to heat our homes accounts for over 30% of the UK’s carbon emissions but because hydrogen does not create any carbon when used it can play a key role in meeting climate change targets

Decarbonisation is a huge challenge and means we need solutions to change the way we heat our homes.  A hydrogen conversion reuses the resilient and reliable gas network we enjoy today. For the majority of UK homes it could provide the most cost effective and least disruptive route to heating homes without creating carbon emissions.

The H21 programme has demonstrated that a conversion from natural gas to hydrogen is technically possible and economically viable. (report link).

Other projects include social science work to understand the public’s view of a hydrogen conversion, our phase 1 testing programme and strategic modelling of major urban centres.

The Government’s ten-point plan to achieve the Net Zero target commits to the production of hydrogen for transport, home heating and industry. The plan includes pledges for hydrogen blending, a neighbourhood receiving hydrogen by 2023 and a whole town, with tens of thousands of homes, receiving hydrogen by the close of the decade. 

The plan also included plans to stimulate 5GW of low carbon hydrogen production by 2030.

Current appliances are designed to work with up to hydrogen blend of up to 23% but they will not operate with a 100% hydrogen gas supply.

Hydrogen appliances have been developed by leading manufacturers including boilers by Worcester Bosch and Baxi Heating. The boilers look and feel just like those we use today and other appliances including fires, cooker and hobs are also being developed. A hydrogen conversion would take place over many years just like the conversion to natural gas in the 1960s and 70s. When appliances reach the end of their natural life customers would replace them with hydrogen-ready replacements. These new appliances would then need some small adjustments by a gas engineer when an area was to be converted to a hydrogen gas supply. This means a hydrogen conversion could provide the least disruptive route to net zero carbon heating for most homes as the pipework and radiators will work the same.

Whichever route is taken to net zero carbon home heating, there will be a cost implication, particularly in the short term. We believe that a hydrogen gas network will offer the most cost-effective solution for the majority of homes currently connected to the gas network. At present the hydrogen boilers developed cost a little more than a natural gas boiler but once they are in mass production and demand increases the cost should reduce to be comparable to today’s gas boilers.

There are lot of different factors which affect the cost of home heating, such as improved insulation. Appliance manufacturers have indicated that their hydrogen appliances will be more energy efficient than today’s natural gas versions.

The production of hydrogen at scale is in its infancy and needs to be upscaled to meet the demand a hydrogen gas conversion would create. Large companies, such as BP have committed to producing hydrogen.

No, your current pipework and radiators will still work with a hydrogen supply. This is why, for homes connected to the gas network, a switch to a hydrogen supply is the least disruptive route to zero carbon home heating.

There are various ways in which hydrogen can be produced. To ensure zero emissions the hydrogen produced would need to be what is known as blue or green hydrogen.

Blue hydrogen is created from natural gas through the process of steam or autothermal methane reforming (SMR).  The carbon is captured and stored underground using Carbon Capture, Utilisation and Storage (CCUS) technology.

Green hydrogen refers to hydrogen produced via the electrolysis of water, with the electricity used in the process coming from renewable sources like wind and solar to ensure it is carbon free.

A nationwide rollout of carbon-free hydrogen could allow the UK to reduce carbon emissions by the 30 per cent which come from domestic heating and cooking.  Around 85% of homes are connected to the gas grid and a hydrogen conversion reuses the billions of pounds of pipework and assets which are already in the ground and delivering natural gas.

A hydrogen network can become an anchor for further innovations in the sector, and in other industries such as transport, energy storage and electricity generation. This means further cost and carbon reductions will be achieved.

Jobs will be created across the energy supply chain; from the appliance manufacturers to the gas transportation businesses as they prepare for conversion to hydrogen. Jobs will also be created in construction and the carbon capture infrastructure sector, as well as in wider industries such as car, train and plane manufacturers who are able to adopt hydrogen innovations.

Hydrogen is a flammable substance that needs expert management, just like the natural gas we use today. Town gas, which was used in the UK gas industry for 150 years, and is still the gas used in Hong Kong, contained up to 50% hydrogen so it’s not the first time hydrogen would be supplied as part of the gas supply.

The UK gas industry has a fantastic safety record and it’s imperative we preserve this. Our current H21 work to understand the implications of a hydrogen gas network will identify how hydrogen can be delivered as reliably and safely as natural gas is delivered today.

Following the discovery of natural gas below the North Sea, the UK undertook a successful gas conversion between 1967 and 1977. The way the conversion was tackled, with areas sectorised and upgraded sequentially, holds a lot of merit and provides us with a blueprint for how we would carry out a UK-wide hydrogen gas conversion.

The H21 team recently modelled the gas networks in the urban areas of Bournemouth, Cardiff, Edinburgh, Hull and Beverley, Liverpool, Teesside and West Yorkshire to explore how well a 100 percent hydrogen network could meet customer gas needs. We were able to identify the work involved in building the conversion strategy for each town.