The emergence of household batteries, along with small-scale solar photovoltaic and plug-in electric cars, is slated to transform electricity storage, according to a new state-of-the-art report by European science academies. But experts claim storage is not actually fundamentally needed.
“Storage is widely acknowledged today as an expensive option, but its costs are falling and its value is improving,” said a new report by the European Academies of Science Advisory Council (EASAC), published on Monday (19 June).
The report takes stock of the latest scientific evidence on the use of storage in electricity grids and highlights what policymakers can do to boost grid-connected storage in the future.
But despite growing interest and billions of investment, no new storage technologies are expected to be commercially deployed on a large scale before 2030, said the report, which represents the consensus among the national science academies of the 28 EU member states, plus Norway and Switzerland.
For decades, hydro power plants built on mountain dams and lakes have acted like super-sized batteries, allowing a convenient form of storing electricity on a large scale. But scientists have until now failed to crack the nut of storing large amounts of power on the electricity grid.
Now, new consumer products like Tesla’s grid-connected home battery, coupled with the rise of small-scaled renewables and electric vehicles, are becoming more popular, and are tipped to revolutionise the way power is stored.
“The deployment of lithium-ion batteries is growing fast and growth is also expected in the deployment of other energy storage technologies,” the report notes, pointing to the rising number of households investing in solar panels and battery systems for self-consumption.
And policymakers are convinced that a revolution is genuinely underway.
In its electricity market design initiative presented last November, the European Commission hedged its bets on a future where household batteries, solar panels and plug-in electric cars are all connected to the grid and can feed power back to the system when needed, helping to keep the grid in balance.
No clear winner
However, the report by EASAC said there were no clear indications yet as to what technology would emerge as a winner.
“There are many conflicting claims and projections for current and future costs of the different storage technologies,” the report said, noting that “major investments are being made worldwide in new mass production plants for producing lithium-ion batteries”.
And although lithium-ion technology has tended to dominate headlines, hydro power should not be discarded just yet, the researchers said – at least when it comes to large-scale grid storage applications.
“Pumped hydroelectric storage (PHS) and possibly lithium-ion batteries appear to be ready for large-scale deployment over the next few years in grid-connected applications in the EU,” the report said.
The good, the bad and the ugly
In fact, Professor Mark O’Malley of Canada’s McGill University and University College Dublin, said electricity storage has “the good, the bad and the ugly”.
“The good about storage is that it’s incredibly versatile” and can contribute to all aspects of the electricity system, said O’Malley who coordinated the study for EASAC.
“The bad is that it has to compete against everything else. There is nothing that storage can do that something else can’t do,” O’Malley told the audience at an event held at the Royal Academies for Science of Belgium.
“Storage as a technology – remember it’s not needed fundamentally. And it has a capital cost. So that’s a challenge,” said O’Malley.
Still, as increasing amounts of intermittent renewable energy come on stream, the value of storage rises because it brings flexibility to the system and helps balance load, he remarked.
“However, flexibility can be provided by a lot of competitors. Storage has nothing unique in the flexibility market. It’s very flexible, no doubt about it, but in many ways other technologies can do the same thing,” he said referring mainly to demand-response capacity.
Subsidies for storage?
Claude Turmes, a Green MEP from Luxembourg, is a big believer in the emerging market for so-called “flexibility services”, predicting it will boom in the coming years as wind, solar, battery storage, power-to-gas and other demand-side services grow in popularity.
But he also admits that the battery issue is a bit of a hype. “Personally, I think this storage question is probably exaggerated,” Turmes said, adding it nevertheless needs to be addressed.
“The one question we will have to deal with as policymakers is do we want a subsidy regime for storage,” or can it can be delivered by market forces alone, Turmes said, referring to ongoing European Parliament discussions on the electricity market design proposal, which are expected to conclude after the summer break.
“It’s a damn difficult question to know how exactly we will drive storage” in the future, Turmes said, stressing that ICT-based demand-side management solutions should also be seen as part of the flexibility equation.
Frauke Thies, executive director at the Smart Energy Demand Coalition, an industry group, agreed, saying energy storage and demand-side response should not be seen as competing against each other but as two sides of the same coin.
“It’s going to be harder and harder to distinguish” between smart demand solutions driven by ICT and storage, Thies underlined. “For instance if I charge my electric vehicle – is that storage or is that demand response? I think it’s become quite blurry in a way”.