The argument that renewables are intermittent has long been used against the sector. So for many, energy storage and its ability to supply electricity to the grid if and when it is needed, is seen as an essential counterpoint against these claims.
To back this up, a recent survey of renewables companies by certification agency DNV GL found two-thirds believed the development of storage was important in terms of bringing more renewable energy onto the grid.
Out of all renewable energy forms, wind is the one to be most optimistic about when it comes to large-scale adoption of storage solutions. It is still at an embryonic stage yet around the world, there are a number of projects in production.
In the US these include RES’s 7.8 MWh Jake Energy Storage Centre and the 7.8MWh Elmwood Energy Storage Centre, both in Illinois and to be completed in Q3.
In the UK, storage projects include a 10MWh system located at Leighton Buzzard, Buckinghamshire, which was built by automated battery specialist Younicos. Elsewhere, the National Grid as part of the Enhanced Frequency Control Capability (EFCC) has brought in Belectric to built two battery storage projects. One of these will be co-located at Willersey Solar Farm, a 3.8MWh project completed towards the end of last year.
However, the UK is lagging behind other markets despite the technology being relatively mature. This is despite being a potentially ideal fit with solar due to the type of projects and scale that storage solutions can be deployed.
One project in the UK is the Big Battery at Leighton Buzzard, Buckinghamshire that was built by battery specialist Younicos. Younicos consultant Phil Hiersemenzel said: “We see a big role for storage with solar being so cheap that its cost-competitive for the base load.”
Short-duration use is the first step but operators will need to look higher than that if they want to bring more solar onto the grid. Hiersemenzel said: “Our studies of systems from around the world have shown time and again that storage in range of hours will you get you as high as 60% renewables integration. Higher than that that it will require storage in the range several hours/days then after that 80% you need monthly/seasonal storage — for which you won’t be able to use batteries anymore.
“A lot of people say you need storage because the sun does not shine at night but that’s only if you have 60% input into the grid. What you need is storage for when cloud is covering over the solar panels.”
Currently, storage refers to a whole suite of technologies. This includes innovative flow batteries on the market, but the market seems to be settling on lithium-based projects and products. “Lithium-ion is the most competitive because It’s been mass-produced for the car industry Sodium sulphur and Vanadium-Redox-Flow are also very promising stationary storage technologies,” added Hiersemenzel.
Yet despite falling prices for lithium-ion, cost continues to be an issue. Philip Totaro of Totaro Associates said: “Average cost for storage is still about 10-times what it needs to be in order to be more universally implemented.
“Presently, Lithium-Ion and other conventional battery technologies are seeing the greatest use. Look for a next generation with flow batteries and Aluminium Ion to make there way into the mix within the next 5-7 years as those technologies go from prototype to wider production.”
However if the technology is there, something is clearly amiss. Most observers point out that storage is being failed by the current energy policy framework. In this storage projects are neither user or generators of electricity. This has not been helped by a solar feed-in-tariff that pays for what you generate even if it is not used.
Referring to a recent meeting of the Energy and Climate Change committee meeting, Energy Storage Network director Jill Cainey said: “Amber Rudd said storage was vital to the introduction of renewables. The problem for storage, is it’s seen as a nice to have.”
This is backed up by Bloomberg New Energy Finance analyst Logan Goldie-Scott. “The market in the UK has been designed around fossil fuel generators. All of the market payment mechanisms are based around that idea. If you take frequency regulation for instance there’s not a clear way storage can be competitive because there’s not a performance payment.”
He added the main reason is that renewable energy developers have no incentive to add energy storage since there is no mandate and most payments are not based on time of delivery. “The market for utility-scale solar in the UK is virtually non-existent at the moment. Any projects are being built on a demo basis.”
Questioned about its commitment to storage the Department of Energy and Climate Change (DECC) defended its record saying around £80 million had been spent on R&D in storage since 2012. It said this included projects “funded by DECC, the Research Councils, the Energy Technologies Institute and Ofgem’s Low Carbon Network Fund. This R&D activity has helped to raise the profile of storage and to demonstrate its capabilities to potential investors”
However, DECC said the UK’s capacity targets were not dependent on storage. A Decc spokesman said: “Energy storage could help us to use energy more flexibly and to decarbonise our energy system cost effectively. It is not, however, the only tool that we have at our disposal. We could, for example, increase demand response, use more inter-connectors or make more dynamic use of networks.”
Goldie-Scott also questioned how essential storage is to integrate more renewables into the grid. Citing the future role of inter-connectors, he also pointed out that the grid has become increasingly able in terms of its ability to incorporate renewable energy.
But in spite of this, there is still plenty to play for. In Goldie-Scott’s view storage could be a possible solution to high grid connection costs making projects uneconomical. Developers could install storage on make a project viable and avoid incurring penalties for overloading the grid. He said: “Developers are exploring the option that if they [use storage to ] deliver a couple of hours, could that help the connection costs.” But, he added, despite a number showing an interest in this option, no one has done it yet.
Additionally, thanks to initiatives overseas the sector appears to be maturing. Goldie-Scott said: “In storage, many companies have promised great things and have failed to deliver a commercial product. The market is littered with companies that have gone bankrupt or failed to deliver and are no longer around.”
According to a study by research consultancy Frost and Sullivan, the market is set for growth. Last year it was $0.46 billion but this to reach $8.30 billion in 2024. In addition to the US, South Korea and Japan has also been supporting the sector and bigger companies are now coming to the fore. Samsung and LG Chemicals have a 20% and 30% share of the market respectively.
If large-scale storage solutions are built elsewhere in the world, that too could stimulate the UK to take more of an active role in their development.