Hydrogen in homes is 'a dangerous pipe dream' — the leaky US gas grid will not be able to safely handle H2: report

Utilities are using clean H2 as an excuse to delay the phase out of natural gas, says non-profit Food & Water Watch

Workers from energy provider Eversource working on pipes in 2019 following a major gas leak in Lawrence, Massachusetts, that forced residents to evacuate their homes.
Workers from energy provider Eversource working on pipes in 2019 following a major gas leak in Lawrence, Massachusetts, that forced residents to evacuate their homes.Photo: Boston Globe/Getty
The use of hydrogen in US homes — for heating and cooking — is a “dangerous pipe dream” being used by utilities to justify the continued use of natural gas, according to a new report from Washington DC-based non-profit organisation Food & Water Watch.

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The ten-page study, entitled Hydrogen In Our Homes: A Dangerous Pipe Dream, states that America’s “rickety” gas grids already leak a lot of methane, and leaks will increase if the fossil gas is replaced partially or fully with hydrogen, due to the latter’s smaller molecule.

“Hydrogen is the smallest element and is very likely to leak from pipelines designed for natural gas,” it says. “Depending on the type of material and on the construction of the pipeline, hydrogen leaks at about three to five times the rate of methane.”

“Hydrogen’s small size allows it to leak through threaded fittings, gaskets and valve stems,” the report explains, pointing out that the pressure of gases in the pipes would have to be increased to transport hydrogen, due to H2’s lower energy density by volume.

“Even the best-designed pipes are prone to leaks when added [hydrogen] supply increases operating pressures on local distribution lines.”

On top of this, hydrogen can cause embrittlement, damaging pipes and therefore increasing the risk of cracks and ruptures.

“Despite these dangers, hydrogen transport is regulated far less in the US than in other countries,” says the study.

It points out that only 30% of existing gas distribution mains in the US were installed this century, while nearly 10% were built before 1940 or have no known installation dates.

“These older pipes are particularly prone to leakage, contributing to an estimated 659,000 leaks from the gas distribution system in the US annually,” the report explains, citing a 2020 peer-reviewed scientific study.

While proponents often argue that the existing gas infrastructure is an asset that should continue to be used as the country decarbonises over the coming decades, “a close investigation of natural gas infrastructure shows that there is little worth saving,” states the watchdog.

Blending

Food & Water Watch argues that when utilities promote the use of hydrogen in existing fossil-fuel pipeline, “what is really being pushed is a dangerous scheme to mix relatively small amounts of ‘clean’ hydrogen into the natural gas fuel stock” — ie, blending.

“This plan would prolong the life of existing fossil fuel infrastructure and let utilities profit from their ongoing dirty investments,” it says.

“Further, using hydrogen in existing fossil fuel infrastructure faces severe technological, environmental and economic challenges.

“These proposals to replace natural gas with hydrogen [in the power sector] only serve to justify inaction and distract from economically feasible and environmentally sound energy storage solutions.”

The report points out that about three times as much hydrogen is required to produce the same amount of energy as natural gas due to its lower volumetric energy density.

“So, at power plants, blending 5% hydrogen only reduces natural gas use by 2%,” it says, adding that the use of hydrogen will also add “significant costs”.

“Using just 30% hydrogen [in a blend with natural gas] could raise costs by $6.9 to $11.6 per MWh, but only reduce CO2 emissions by 4.8 to 11%. For comparison, solar costs about $36 per MWh, but is capable of reducing 100% of the emissions from natural gas power plants, making it between 1.7 and 6.7 times more cost-effective than hydrogen at reducing emissions.”

Health risks

The paper also states that even small amounts of hydrogen in the gas supply “could pose tremendous risk to people who use gas in their homes or live near gas storage facilities and pipelines”.

“Adding hydrogen into the mix will increase the risk of pipeline blowouts and explosions of gas-powered appliances.”

It explains: “Hydrogen gas travels at a high speed, making flash-back (when flame travels back toward the source) in burners more likely, thereby necessitating different water heaters, boilers, and stoves that can accommodate a mix of hydrogen and methane.”

This contradicts proponents of blending, who frequently argue that existing appliances can safely manage hydrogen blends of up to 20%.

“Lower air requirements make hydrogen more likely to burn backward into pipes, generating high-pressure explosions that destroy buildings and throw shrapnel,” it adds, citing a US congressional report from 2021.

Gas companies argue that hydrogen is just as safe as natural gas in the home, although one UK government study said homes using hydrogen would be four times more likely to suffer explosions compared to natural-gas users, although this could be reduced to acceptable levels with the introduction of two excess flow valves, and additional non-closeable vents are recommended.

“Explosion is more likely with hydrogen, as igniting hydrogen requires significantly less energy than natural gas,” the US watchdog’s report adds, citing peer-reveiewed scientific studies. “Hydrogen is 14 times as flammable as natural gas and can be ignited by static electricity.

“Friction, heat, and electrical fields can all ignite hydrogen.”

Conclusion

The report argues that electric heating solutions based on the direct use of renewable energy “have a proven track record at low costs”.

By contrast, “a hydrogen future would be an expensive and frightening mess”.

“But these outcomes could be easily avoided so long as political leaders recognise these hydrogen blending schemes for what they are: A last ditch attempt to protect a dying industry from safer, more effective technologies.

“It’s time to fight for a renewable and electric future — one that we have the power to win.”

  • Food & Water Watch describes itself as a watchdog that fights for safe food, clean water and a livable climate” and to “protect people from the corporations and other destructive economic interests that put profit ahead of everything else”.
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Published 20 April 2023, 08:12Updated 20 April 2023, 08:13