UK energy minister, Lord Callanan states that it is pretty much impossible to heat homes using clean hydrogen. He makes this the comment as the British Government continues to invest millions of pounds in hydrogen heating trials.
“If I’m being honest, the idea that we could produce enough hydrogen at reasonable cost to displace mains gas is pretty much impossible,” said Lord Callanan, parliamentary under-secretary of state for climate change & corporate responsibility at the Department for Business, Energy, and Industrial Strategy.
The experts, led by Cambridge University professor David Cebon, argue that rather than attempting to convert the existing gas grid to use hydrogen — an expensive and difficult proposition – the government should instead put its efforts into promoting low-carbon electric heating solutions. “Hydrogen use in buildings and for road transport is not efficient and does not make economic sense,” they write. “Hydrogen is a not an efficient energy source, which is a fundamental flaw when comparing it with other electrification alternatives.
The UK’s National Hydrogen Strategy unveiled in August states that hydrogen has the potential to play a key role in decarbonizing heat in the buildings in the UK. Currently, the UK Govt. are investing millions of pounds in studies on hydrogen heating, with £25 million ploughed into the Hy4Heat programme (a pilot scheme in Scotland to heat 300 homes with 100% hydrogen via the existing gas grid due to take place in 2023, backed by up to £18m of grants from the industry regulator Ofgem; and plans to heat a whole town with H2 by 2030).
Although, they may be fighting a losing battle. Green hydrogen is expensive to produce and is not as efficient as electricity. With electric heat pumps being six times more efficient, meaning that a boiler burning green hydrogen would require six times as much renewable energy as compared to a heat pump to produce the same amount of heat- making this an extremely expensive proposition (Recharge-News, 2021).
With green hydrogen being so expensive to produce, one may suggest blue hydrogen. The scientists who wrote an open letter to the UK’s Prime minister, Boris Johnson also stated: “take a cautious approach to blue hydrogen, avoiding lock-in to unsustainable fossil fuel infrastructure that could push net-zero out of reach.”
They write: “By choosing to support blue hydrogen made from natural gas and CCS [carbon capture and storage], the UK must have stringent measures to assess the greenhouse gas emissions from the blue hydrogen manufacturing process and supply chain.”
Grey Hydrogen is not an option. Grey hydrogen is made from unbated fossil fuel accounts for roughly 3% of the world’s greenhouse gas emissions (about the same proportion as aviation).
The cost of converting the natural gas grid to run on 100% clean hydrogen would also be astronomical, with every compressor and valve on the network needing to replaced, metal pipes switched out with plastic ones (including in people’s homes) to reduce the risk of the smaller molecule leaking. It also requires three times the energy to transport the gas around the grid (Recharge-News, 2021).
Energy Minister, Lord Callanan concluded by saying that a scientific breakthrough might enable us to produce large amounts of hydrogen at a cheaper cost. But he admits it is more likely that hydrogen will end up being used by trains, HGVs (heavy-goods vehicle) and for some industrial processes.