With more electricity often generated than needed the excess could be utilised to generate the green power source
Green energy would be boosted if excess electricity from wind and solar farms was used to produce hydrogen for use in heating and other parts of the energy system, according to engineers.
Renewables were the UK’s second biggest source of electricity in the last three months of 2017, and now provide about a third of the country’s power at certain times of day.
National Grid has warned that at times this summer there will be more electricity being generated than needed; when demand is low, solar output is high and some inflexible power stations are hard to turn off.
With a significant number of large new offshore windfarms due to come online over the next few years, the challenge of balancing supply and demand will continue to grow.
The Institution of Mechanical Engineers (iMechE) said the answer could be to use the power to generate hydrogen.
Electricity would be used to split water into hydrogen and oxygen, with the hydrogen functioning as a form of energy storage for renewables. The gas would later be blended in with normal gas supplies for heating supplies, sent to fuel cells to generate electricity, or used for topping up hydrogen vehicles, iMechE said in a report backed by the gas industry.
Dr Jenifer Baxter, the report’s lead author, said: “We are seeing continued expansion of renewables. If we’ve got a lot of low-carbon power, we want to make sure we’re using all of that.”
The engineering group urged the government to bring the renewables, nuclear and gas industries together to work on “power to gas”, and encourage demonstration projects. The nuclear trade association welcomed the report.
The iMechE also called for a government study into the environmental impact of lithium-batteries, which have been deployed on a large scale recently and offer an alternative way of storing energy.
Asked if the economics of hydrogen stacked up, Baxter said electricity was getting cheaper while electrolysers – used to split water into hydrogen and oxygen – were getting more efficient.
“This is part of a pattern of the gas industry trying to get that hydrogen route more in the debate. Policymakers need to look at the alternatives as well [such as electrification of transport and heat],” he said.
Separately, a new report on Wednesday warned that there were “major technical challenges” to decarbonising heating by switching to greener gases such as hydrogen.
The Oxford Institute for Energy Studies said there are not yet any obvious ways that the technologies could achieve major reductions in cost.