A report published by trade association RenewableUK at the beginning of May showed that the total pipeline of battery projects reached 95.6GW, a two-thirds increase on last year. The total includes operational battery projects, under construction, consented to, or planned projects.
Battery storage plays a key role in grid decarbonisation, namely electrification. As RenewableUK acknowledged in its Energy Storage EnergyPulse report, while growth is positive for the battery sector, it also causes further congestion up the transmission entry capacity (TEC) register, more commonly known as the connection queue.
Over 700GW of capacity is now waiting for a connection, much of it storage, and connection dates are being offered into the late 2030s.
Alongside this trend, increasing numbers of second life batteries are becoming available as they reach the end of their first life in a vehicle; a battery that reaches the end of its life in an electric vehicle (EV) still retains 75-80% of its capacity, according to Connected Energy.
Connected Energy uses second-life batteries to deliver battery energy storage systems (BESS). Second life battery storage extracts additional value from the finite resources embedded in existing batteries – eliminating the need to manufacture new batteries and subsequently removing the need to source the already limited critical minerals required to build them.
Current± spoke with Matthew Lumsden, Connected Energy CEO, to find out how second life battery storage can be deployed for both the storage and the EV industries.
Delaying battery recycling
Premature end-of-life battery recycling is, to some extent, a waste of resources. Reusing batteries reduces environmental impact and means less reliance on virgin materials in the supply chain.
It is also worth noting that second life battery application does not reduce its recycling value.
Beyond this, due to the speed at which recycling processes are improving—yielding higher-quality recyclate—using a battery for a second time means that in the long term, more value will be gained from recycling it.
Lumsden points out that original equipment manufacturers (OEMs) are obliged to include increasing amounts of recycled material in their new build. Higher quality of recycled material means higher value as it returns to the new build.
Connected Energy has about 30 commercial systems operating in the UK, Belgium, Germany, the Netherlands and, most recently, Sweden. It has also collected an ‘awful lot’ of data, providing the company with a good understanding of how second life batteries perform in duty cycles that are different from on-road duty cycles.
Without a consistent flow of batteries, second life has been challenging. However, between now and 2030, there is potential for gigawatt hours of second life batteries to become available.
Lumsden says: “A lot of people own a lot of batteries that are going to come into the end of their first life within the next five years and [they] are going to be looking for somebody who’s able to monetise those batteries before they’re recycled.”
Policy is starting to emerge supporting the reuse of batteries in Europe, India and the United States. While the UK has been slower to make change, policy drivers are moving in the right direction.
The next five years will see the critical components coming together to enable second life batteries to deploy at scale.
Safety concerns
According to Lumsden, the process of reusing EV batteries in BESS has to involve the whole supply chain, starting from the OEM – be it batteries or automotives. This not only shares the risk of investment but also underpins safety.
“If you work with the people that own the battery management system then, firstly, you are sharing the risk of the investment but you are also underpinning the safety.”
By only using second life batteries from OEMs that partner with Connected Energy, it can capitalise on what has already been invested in the design of the battery, its control systems and its safety systems. In an emerging industry, this is crucial.
In general, BESS failure follows a bathtub curve, which, according to Lumsden, is mitigated by second-life batteries because any commissioning or build faults will have been identified and solved.
Further, EV batteries used in second-life BESS come from a consumer product, so they have in-built, high-standard safety.
“These batteries have already been designed so that you can drive down the motorway with your family sitting on top of it. They’re probably the safest batteries in the world anyway – you need to harness all that work that has gone on in advance,” Lumsden says.
“In terms of that whole value chain piece, in order to scale you have got to work with the battery supplier, you have got to work with people who are financing projects, with recyclers, et cetera, so that you get a model that works for everybody.”
Having worked closely with OEMs, the expected performance of batteries from their point of view is familiar to Connected Energy. The company’s data shows that batteries are performing in a homogenous way, in the way OEMs predicted.
Underpinning EV charging infrastructure
Second life EV batteries can be used for BESS, but energy storage stands to benefit EV infrastructure, too. As built out and chargers become more powerful, it can be difficult to get the necessary grid connections to provide sufficient infrastructure.
Storage can be used as an alternative to manage grid load until connection is upgraded. “It is quite an enabling technology.”
Providing a second life for batteries used in EV fleets – usually for a period of about eight years – puts residual value on the battery, which can be fed into the fleet business model.
Lumsden points out how, if fleets understand what residual value looks like, EV adoption becomes more appealing.
Further, fleets need charging infrastructure, be it hubs, on the motorway, at the fleet operator site or depots. Again, connection difficulties arise, as does the issue of resilience. Incorporating a battery helps with grid load management, and with additional use of solar, businesses can capitalise on renewable generation to decarbonise fleet operations.
Connected Energy set up its original prototype over ten years ago combining charging stations with PV canopies and a micro wind turbine,, then developed its energy storage system using six different types of second life batteries. Microgrid control software then enabled these to be linked, the use of storage to grid load and EV charger management.
Lumsden says: “We set up a handful of chargers, a PV canopy and micro wind turbine, and developed our energy storage system using about six different types of second life battery. Microgrid control software enabled us to link all these things together and use the storage to grid load, manage the EV chargers, decarbonise the electricity that went into chargers.”
Still, for Lumsden, technology is just part of the solution; the business model is the big enabler.
“There are three elements to that. Part of it is around reducing costs, part of it is about decarbonisation, and part of it is around enabling a smarter use of energy, or smarter use of carbon.”