Hydrogen could prove inefficient for heating homes, despite government claims

Hydrogen will not have a major role in the future of heating homes across Britain, according to a peer-reviewed analysis of more than two dozen independent studies, published in the academic journal Joule.

The research found that using hydrogen in domestic heating is less economic; less efficient; more resource intensive, and has a bigger environmental impact than many alternatives, including heat pumps, solar thermal panels and district heating (where whole blocks or neighbourhoods are supplied through the same hot water system).

The academic findings contradict recent statements made by business secretary Jacob Rees-Mogg, who told the House of Commons last week that hydrogen was a "silver bullet" that could be used as a way to store excess renewable power and "with some adjustments piped through to people's houses to heat them during the winter." 

Last year, the government also claimed that by 2035 hydrogen could be playing a big role in heating homes and cutting greenhouse gas emissions. However, all of the 32 studies reviewed by researchers found that hydrogen was much less efficient and more costly than alternatives such as heat pumps.

“Using hydrogen for heating may sound attractive at first glance,” said Jan Rosenow, Europe director at the Regulatory Assistance Project think tank in Brussels, who led the research. “However, all of the independent research on this topic comes to the same conclusion: heating with hydrogen is a lot less efficient and more expensive than alternatives such as heat pumps, district heating and solar thermal.

“Rather than hoping for hydrogen to eventually be able to replace fossil gas used for heating our buildings, we should focus on speeding up the roll-out of energy efficiency and heat pumps, technologies consistently identified as critical for reducing carbon emissions from buildings.”

Proponents of hydrogen for heating say that the gas could tap into the existing natural gas pipelines that currently connect to most homes in the UK, and have stressed that it would be easier to reconfigure homes to run with hydrogen boilers.

They argue that green hydrogen can be produced using renewable electricity to split water molecules into hydrogen and oxygen. However, this process is significantly inefficient and, thus, only 5 per cent of hydrogen is made using this method. The vast majority of hydrogen - 95 per cent - is produced by splitting natural gas into hydrogen and carbon, a process which is more polluting than just using methane gas. 

Therefore, generating electricity from wind or solar, converting it into hydrogen and then burning the hydrogen at home uses more energy than just using the electricity to directly heat a home with a heat pump.

"In the UK, heating homes with green hydrogen would use approximately six times more renewable electricity than heat pumps,"  David Cebon of the Hydrogen Science Coalition and Professor of Mechanical Engineering at Cambridge University, told the BBC. "We do not have the time or resources to waste further investigating hydrogen's role in home heating, especially when the well-known laws of thermodynamics determine the answer." 

As the UK faces a looming energy crisis, the topic of heating homes is becoming an increasing concern for most of the population. Currently, around 50 per cent of global final energy use in the world today is used for heating and cooling. In the UK nearly nine in 10 households use natural gas to heat their homes.

The report said there was a risk that discussion of hydrogen for heating in the future led to a delay in the deployment of clean heating technologies that are already available today, such as heat pumps. Although heat pump installation has a high upfront cost, a report by the Tony Blair Institute claimed that government investment in this and similar low-carbon heating technologies could halve average heating bills by 2035. 

Michael Liebreich, Bloomberg New Energy Finance founder and chairman of Liebreich Associates, said: “This is a timely paper, showing that no serious analysis has hydrogen playing more than a marginal role in the future of space heating. We need to get Europe’s heating systems off natural gas and we need to do it without further delay.

“It’s time to stop the fight: the judges are unanimous and the winners are district heating, heat pumps and electrification."

Instead of using green hydrogen for heating homes, which is said to be costly and inefficient, the authors of the study have called for this fuel to be used in the parts of the economy which electrification cannot reach, such as in heavy industry, to store electricity and to run ships. 

Despite the UK government's claims, this is not the first time that the scientific community has warned against the use of hydrogen for heating homes. Earlier this week, a separate study by the analyst company Cornwall Insight concluded that hydrogen would be close to twice as expensive for home heating as using gas alone.

In addition, a report from Imperial College London’s Energy Futures Lab, released in January this year, said it was likely that using hydrogen as an energy source in the gas grid would only be workable from the early to mid-2030s, at the earliest. 

However, the gas lobby has celebrated Europe’s push towards hydrogen and the goals set in the 2020 EU Hydrogen Strategy. James Watson at Eurogas, one of Europe’s largest gas lobbying groups, said that ramping up hydrogen is a “future-proof solution to achieve climate neutrality and provide Europeans with millions of jobs in clean technologies made in Europe”.