But a year-long experiment that will begin at the university this summer may help the UK inch a step closer to the campaigners’ demands to slash greenhouse gas emissions to net zero.
Up to 20 per cent of the gas that serves 130 university buildings at Keele will be made up of hydrogen, one of the greener alternatives to the natural gas that is currently used to heat more than 80 per cent of homes in the UK.
The trial, on Keele’s private network of gas pipes, is the first modern, practical experiment in the UK involving a blend of hydrogen and natural gas and will not involve any changes to appliances.
Organisations involved in the project, including Cadent Gas and Northern Gas Networks, hope it will be one small step along the path to potentially replacing natural gas with hydrogen altogether to heat buildings.
The question of how to decarbonise domestic heating in Britain has taken on added urgency in recent months, with the government’s official advisers on climate change urging in February that no new homes be connected to the gas grid by 2025 “at the latest”.
Greenhouse gas emissions reductions from homes are currently “off track”, the Committee on Climate Change warned, adding that Britain would miss its 2030 climate target to reduce greenhouse gas emissions by 57 per cent from 1990 levels without them.
Radical alternatives to natural gas will be needed if the UK is to meet its legally binding target to reduce carbon emissions by at least 80 per cent below 1990 levels by 2050, experts said.
“We really need a plan for decarbonised heat to be made by the government over the next three years,” Chris Stark, chief executive of the CCC, later told the Financial Times.
Dermot Nolan, chief executive of the UK’s energy regulator Ofgem, has also warned he was “far more worried” about how to wean households off their gas boilers than decarbonising power generation and transport — two bigger emitters of greenhouse gases — because he does not “obviously see an answer”.
Homes accounted for 18 per cent of UK greenhouse gas emissions in 2018, versus 33 per cent for transport and 27 per cent for energy supply, according to the Office for National Statistics.
Philip Hammond, the chancellor, responded in his Spring Statement with a proposed ban on gas boilers in all new-build homes from 2025, although gas cooking hobs will still be permitted. But energy experts such as Mr Nolan call new homes a “second order area” compared with the bigger problem of converting the 23.9m existing properties heated by natural gas.
There are many immediate steps homeowners, with the right incentives, can take to reduce the carbon footprint of their homes, from turning down thermostats to improving insulation. Injecting more greener gases into the grid will also help. Some biomethane has long been used and the chancellor is keen to increase that proportion.
Longer-term options include pumps that extract heat from the air or ground outside but require electricity to run. Iain Conn, the chief executive of Centrica, owner of British Gas, has said he could foresee his company installing “heat pumps to replace boilers” but some experts suggest they could place a considerable added strain upon power generation.
The Policy Exchange think-tank estimated an additional 105 gigawatts of electricity generation capacity would be needed to convert 80 per cent of UK homes to heat pumps. By contrast, the new Hinkley Point C nuclear plant under construction in Somerset is 3.2GW.
Another option is local networks, where heat is generated by a central low carbon source and distributed to properties via insulated pipes, a system common in Denmark. However, they require a certain density of heat demand to be economic so are best suited to new housing developments or urban areas, according to the CCC.
A third alternative would be to replace natural gas with 100 per cent hydrogen. Unlike the trial at Keele, a full conversion to hydrogen would require cooking hobs and boilers to be replaced. Gas network companies argue that the conversion in Britain in the 1960s of homes from using town gas — which was used before natural gas and was about 50 per cent hydrogen — is proof that such an undertaking is possible.
To produce hydrogen at scale, it is generally believed “gas-reforming” — producing hydrogen from natural gas — is the best solution, although the carbon produced in the process would need to captured and stored.
The CCC believes there is also a “middle ground” that could buy time while research into the longer-term options continues: hybrid heat pumps. These use electricity to heat the home as often as possible and existing boilers are a back-up — for example, when it is very cold.
Solutions are unlikely to be found by the 2025 deadline Extinction Rebellion is demanding to reach net zero but, most experts agree, the difficult question of how to wean British households off their fossil fuel heating cannot be kicked down the road.
“I am determined not to be alarmist about this, this is something we can manage. but it’s important that the framework is in place to do that,” said Mr Stark of the CCC.