While many people made the most of the sudden suspension of modern life, with widespread reports of candle-lit restaurants and al fresco drinks, the blackout was also connected with at least four deaths, groups becoming stuck in lifts and trains, and an estimated cost to the economy of €1.6bn, highlighting our near-total dependence on the grid.
The disruption was a sharp reminder of the opportunities and challenges of grid-scale energy storage, power plant flexibility and industrial decarbonisation – so it was good timing, therefore, that three IMechE events focused on each of those topics took place on 29 April, just a few hours after the Portuguese and Spanish grids were fully restored.
With presentations and discussions covering major carbon capture projects and the use of ‘second-life’ EV batteries for electricity storage, Decarbonise, Power, Store took place at Manchester Metropolitan University. Here are three of the key topics discussed on the day.
‘Cap and floor’ funding for medium-duration storage
Grid-scale battery storage is on the up, according to Gavin O’Leary, head of electricity storage at the Department of Energy Security and Net Zero (DESNZ, often said as Desnez). “We have an enormous amount of lithium-ion grid-scale battery storage compared to what we would have thought possible 10 years ago: five-plus gigawatts (GW) on the system,” he said. “I have to update my lines on that every time I go and give a speech at a conference, because it increases that rapidly.”
Projects with another 17GW of capacity have capacity market agreements, a further 17GW have planning permission and more are at different stages of the planning system, helping make an important contribution to the UK’s net zero efforts by storing and releasing green electricity over several milliseconds to a few hours.
Deployment of longer-term energy storage projects (such as pumped hydroelectric storage) has not been as straightforward, O’Leary said, describing it as “a more classic case of a market failure that requires government intervention”.
“Our diagnosis of the problem is that there is a degree of uncertainty in delivering and monetising these projects, which stops the private sector from doing so, even though there are huge societal benefits,” he said.
The government and Ofgem hope a new ‘cap and floor’ scheme for long-duration electricity storage could start to tackle the problem. The model is designed to guarantee a minimum income for developers, while making sure that revenues above a certain level go back to consumers.
While the government hopes market competition will improve lithium-ion and pumped hydro storage, the new scheme is aimed at technologies at or below technology readiness level (TRL) eight, which O’Leary said included compressed air storage and flow batteries, which are often described as medium-term storage, and liquid air energy storage, which is long-term.
The model is designed to “make sure that there is some pipeline for stuff that's not quite at the most commercially proven level… where it’s able to make the case that it’s deliverable and can add value to consumers,” O’Leary said. “As long as there is a chance that we can develop something that is more efficient, that can store more power for a lower cost, that feels worth pursuing.”
Flexibility can boost capacity
For Jordi Carbonell Pradas, power systems engineer at UK Power Networks Distribution System Operator (DSO), the Iberian power outage was of more than professional interest. After noting that it was too early to comment on the reasons for the incident in his native Spain, he fielded a related question on the topic of the session – “The Role of Energy Storage in a Reliable and Resilient Grid”.
Flexibility and making the best use of the existing network are some of the most important criteria for resilience in the European grid, Pradas said, with a need to explore ‘non-built’ digital solutions.
Fellow panel member Christos Kaloudas, capacity strategy manager for Electricity North West (ENW), also stressed the importance of flexibility. The company’s use of flexible connections allows it to “squeeze existing assets” while also connecting over 300 megawatts (MW) of storage in the last four years.
Aiming to be the first “social DSO”, ENW is exploring potential community projects such as locally-powered electrolysis for hydrogen production. Its strategy for emerging technologies is focused on two things, Kaloudas said: releasing capacity at minimum cost for consumers, and accelerating the times it releases that capacity to facilitate “all these amazing technologies”.
“To do that, we have to follow a process that prioritises… flexible connections using our active network management systems that can also deal with transmission constraints. And we have trials this year where we can connect technologies that we couldn't do before,” he said.
“We utilise centralised power flows, and this means that we don't deploy tactical solutions. This means that we can scale up flex connections, flex services really fast, without sub-wiring, without revisiting the rules.”
Hydrogen can ‘buy us some time’
The political landscape – and opinions on hydrogen – have evolved significantly in the last four years, according to Alexander Webb, programme manager for hydrogen blending at gas distribution company SGN. While the government is reportedly “broadly in favour” of blending in hydrogen to the gas network, according to a report in The Standard today (21 May), the industry is still waiting on an official policy announcement.
In the meantime, SGN is already exploring blending – which involves introducing up to 20% hydrogen into pipes alongside natural gas – as well as hydrogen production in H2 Caledonia.
“It's a transitionary solution, but also may have some other long-term applications,” said Webb. Roughly 85% of homes in the UK are connected to the gas grid, and most should need no modification to use a 20% blend. Tests at that level have been carried out at as part of HyDeploy, with trials at Keele University in Staffordshire and in the village of Winlaton near Gateshead.
SGN aims to be “blend ready” in 2027, Webb said, aiming to remove carbon from the grid in the short term. While hydrogen blending for heating might not be a “net zero solution”, it could be a “stepping stone,” he said.
“It's an opportunity to remove carbon from the grid in the shorter term, and it buys us some time in that space. That's a really positive thing, and it supports the industrial clusters. And if the vision is hydrogen for industry, then it still offers somewhere to go in the short term, because you can't just switch off the gas network overnight. That resilience is required so we have those opportunities to remove carbon in the shortest time,” he said.
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