What would hydrogen energy imply for UK houses?

If they wanted to be more green, more than half of households would rather switch to hydrogen power than get a heat pump, a recent survey found.  

But how does hydrogen heating work, when is it coming and what does it mean for energy bills?

The UK is going through a sea change in how it heats homes and powers gas appliances. This is due to the Government’s net zero campaign, which aims to limit greenhouse gas emissions.

A big part of this campaign is replacing the use of natural gas, which is piped into more than 80 per cent of UK homes.

The main alternative to gas boilers is the heat pump, which uses electricity to remove energy from the environment and convert it into heat.

But the Government’s programme to get UK households to fit heat pumps is going slower than expected, with just 55,000 installed in 2023.

Just one in 10 people either have a heat pump or want one, according to a YouGov survey commissioned by the Energy and Utilities Alliance trade body.

But more than half (51 per cent) of said they would support blending natural gas with hydrogen to cut carbon emissions from home heating. Hydrogen can be burned in much the same way as natural gas.

Meanwhile, two-thirds (66 per cent) of people want their current gas boilers to be converted for use with a zero-carbon gas, such as hydrogen, in the future.

So with all the consumer demand for hydrogen power, how likely is it and how does the system work?

What does hydrogen mean for central heating?

Hydrogen can be used to heat homes and power existing gas appliances, such as cookers and hobs, unlike heat pumps which only provide heat. 

Replacing natural gas with hydrogen has several advantages – but disadvantages too.

Burning hydrogen does not create harmful emissions, unlike natural gas which releases carbon dioxide.

Households should not need to make any adjustments to their boilers, meters or pipes if hydrogen of up to 20 per cent is mixed with natural gas.

A report by HyDeploy found that meters were not affected by introducing one-fifth hydrogen to the gas supply.

In fact, all gas appliances made since 1996 are tested on a blend of 23 per cent hydrogen before they can be sold in the UK, due to the Gas Appliance Directive.

So a small amount of hydrogen in the gas system would enable homes to keep their gas boilers and cookers, with most needing no alterations.

At the moment all gas boilers and cookers can safely burn a small amount of hydrogen anyway, but this is limited to 0.1 per cent under gas safety laws.

Hydrogen levels above 20 per cent will begin to require modifications to homes, such as changes to pipes, cookers, boilers and meters.

Why don’t we have hydrogen heating already?

The technology is still young and the Government wants to make sure any hydrogen rollout is done safely with as few snags as possible.

The Government was consulting on plans to start putting hydrogen into gas supplies from 2025, but has now delayed this until at least 2026. Heat pumps will be its focus instead.

Energy efficiency minister Martin Callanan said: ‘Heat pumps and heat networks will be the main route to cutting household emissions for the foreseeable future.’

Is hydrogen heating and cooking more expensive?

Hydrogen is the most common element in the world – and in fact in the known universe – so it is in theory freely available.

But extracting hydrogen and piping it into UK homes is a costly and often difficult practice. 

A major drawback is that the cost of a hydrogen rollout could be more expensive than just installing heat pumps.

A study by energy experts at Cornwall Insight found that hydrogen would be almost twice as expensive for heating a home compared to carrying on using natural gas.

There are also some safety issues with hydrogen. The gas is less safe than natural gas – though neither is perfectly safe. 

Hydrogen is more explosive and more prone to leaking, as it is a smaller molecule than natural gas so can find its way through smaller cracks.

A Government consultation said that older gas meters may also not be able to handle the higher volumes of gas caused by mixing hydrogen with natural gas, and may need replacing.

Some parts of the country are currently unable to get any hydrogen anyway, because the gas mains in their area are made of old iron, which becomes brittle when in contact with hydrogen.

These old iron mains are being replaced by 2030.

What would hydrogen power mean for energy bills?

This would depend on how much hydrogen is introduced and how that is done.

The likelihood is that energy bills would rise if hydrogen is introduced to the gas supply.

Household gas bills could rise by 11.2 per cent if 20 per cent hydrogen is mixed in, according to a 2022 report by German institute Fraunhofer.

However, this 11.2 per cent rise was criticised by energy trial HyDeploy, which said a rise of 6 per cent was more likely in the UK.

But other costs could also hit homes if hydrogen is introduced.

There could be a cost to households if the gas system in their own home cannot handle hydrogen, and this needs to be stripped out before the natural gas can be burned.

The Government consultation on the issue said: ‘For example, there may be costs associated with deblending if users cannot use blended volumes of gas and need to de-blend hydrogen at the point of use.’

A hydrogen/natural gas blend will increase the amount of overall gas being used by households, because hydrogen provides less energy per volume when burned.

For example, a mix of 20 per cent hydrogen and 80 per cent natural gas provides around 86 per cent of the energy of just burning natural gas.

Household energy meters record the volume of gas used, so if hydrogen is eventually piped into the system then meter readings will go up considerably.

Despite this, gas bills should not change from the additional volume – provided hydrogen costs the same as natural gas, which is currently unknown.

This is because gas bills are worked out on the overall energy used by consumers, not the volume.