In a new report, the professional body extols the virtues of the gas as a much-needed source of storage and a “conduit for connecting the energy system together”.
“Government and industry need to step up efforts to provide funding programmes and demonstration sites to encourage the greater use of hydrogen as energy storage,” said lead author and IMechE head of engineering, Jennifer Baxter.
“The UK has a strong track record of being at the cutting edge of new energy developments, and this could present the country with a chance to be a world leader in power-to-gas and hydrogen technology.”
The report says hydrogen has the potential to fulfil a number of key roles, including heating homes, fuelling vehicles, feeding industrial processes and storing up excess renewable electricity for when it is needed.
Using it as part of an integrated energy system would allow gas networks to act as a “lung” for electricity networks. Surplus renewable generation could be converted into hydrogen via electrolysis and injected into the gas grid, before being fed into fuel cells and gas turbines to produce power when renewable output drops.
The report urges caution over the adoption of lithium-ion batteries as the go-to storage solution for both power and transport. It warns that the technology still faces challenges in terms of “duration of electricity storage, efficiencies and losses, size, and perhaps more concerning the sustainability of the materials used in battery technologies and the long-term management of wastes and recycling.”
It notes that, although the majority of lithium used in batteries is currently extracted by evaporating the metal out of brine using heat from the sun, more energy-intensive process such as crushing are expected to be deployed as demand rises.
The extraction of the cobalt used in cathodes is not usually environmentally friendly and supplies may be insufficient to sustain the “electric vehicle revolution” over the long run.
“Another concerning aspect of the life of the lithium-ion battery is the ability to effectively recycle these materials,” the report adds.
It says concerns have also been raised over the use of rare and expensive platinum in fuel cells and electrolysers, but “industry calculations have shown that the total resource requirement for platinum in the latest fuel cell vehicles is broadly similar to that used in catalytic converters for engine-powered vehicles”.
Meanwhile, there are multiple benefits to the use of hydrogen as a storage solution. It can be stored in the gas grid, pressurised canisters or salt caverns for “minutes, days, weeks or months, making it a more valuable medium than the battery”.
Electrolysers can also provide “sub-second response and continuous operating durations of days, weeks or months as required by electricity grid operators, making them a more valuable energy converter than a battery”.
The report includes three key recommendations to accelerate the deployment of hydrogen.
Firstly, the government should create an industrial forum bringing together the nuclear, renewable and gas sectors to promote the use of hydrogen. “Investment now in the future hydrogen economy will begin to encourage further innovation, open up markets and help clarify legislation and regulation,” it explains.
Secondly, the government should work with the gas industry to promote the injection of up to 20 per cent hydrogen into gas distribution networks, including supporting changes to pipes and materials. It says funding programmes and demonstration projects will be crucial: “Government has the power to finance research, development and demonstration and support deployment through programmes such as Innovate UK.”
Finally, the government should commission a comprehensive comparative study of the long-term sustainability of lithium-ion batteries in comparison to electrolysers and fuel cells. This will allow it to make an evidence-based decision on the best solution for the energy system.
Tom Grimwood
This article first appeared on edie’s sister title, Utility Week