Aftermarket July/August 2022 Issue

JULY/AUGUST 2022 AFTERMARKET 17 Renault Kangoo batteries. They were supplied by a British firm called Connected Energy, a world leader in the development and deployment of BESS using second-life batteries. Linking up the EV and energy storage value chain The key challenge to making the widespread use of second-life batteries a reality, is linking up the whole EV and energy storage value chain. Did we mention dots? Success requires industry alignment as well as enabling technology and new business models, like those developed by Connected Energy. Progress is being made. Cranfield University, for example, has just commissioned the UK’s largest BESS system using entirely second-life batteries. It will install three 300kW battery storage units, each housing 24 second-life Renault Kangoo car batteries across its campus in Bedford. Although the overall scale of Cranfield’s three BESS at 900 kW together is relatively small, it is this approach to smaller distributed local energy systems which will help to build national energy security and flexibility, something we describe as a “thin film of energy storage.” A 300 kW BESS can manage the grid supply to a cluster of EV chargers. Even better is when the canopy of the EV charging station holds an array of solar panels and the carbon saving is increased further, as the solar energy is stored in the BESS and used to help supply the EV chargers. Extending the life of EV batteries The case for extending the life of batteries is clear from an emotional point of view; To reduce waste and maximise the use of the precious resources in the battery. The scientific case based on carbon savings is just as clear. A BESS installed today is expected to be operational until 2042. During that time its batteries will need to be switched out a few times. At intervals of around seven years in a second-life system, or ten for brand new batteries. Research conducted by Lancaster University proves that using a first life 360 kWh BESS can give a benefit of 329 tonnes of CO2 emissions over the life of the system, a second-life BESS gives a benefit of 473t CO2e. The second-life system therefore saves an additional 144t CO2e. This calculation is made by comparing an electricity supply where gas peakers are turned up and wind turbines are turned down (as currently happens across the grid), with one where this isn’t required, because a BESS is bridging the gap. This is a massive contribution to CO2 savings which any organisation with carbon reduction or ESG targets will be hard pressed to achieve in any other way. How to identify healthy batteries Readers would be right to have other burning questions though, such as how will used EV batteries be chosen and will they be safe? Batteries are improving in quality all the time, so range is increasing all the time, but the point at which they are considered no longer fit for life in a vehicle is when they reach ~75% State of Health (SoH). Batteries do not have to be discarded when they reach 75% SoH however. They still have significant charge capacity and can be used in battery energy storage systems (BESS) until the battery reaches 50% SoH. This could mean up to ten years’ more life for that battery – hence the massive impact on carbon savings and Connected Energy’s mission - to help maximise the value realised from the resources embedded in EV batteries.To make sure high-quality batteries with known past lives are used, Connected Energy works directly with EV OEMs like Renault who test the batteries to ensure they comply with Connected Energy’s acceptance criteria. Once the batteries are in use, they are monitored individually on a real time basis to ensure that both the cells and battery management systems are working as they should. If any anomalies are identified the battery is isolated, powered down and an engineer is alerted. Individual batteries can be isolated while the remaining system continues to operate. Which battery type is best for a BESS? Of course, the BESS doesn’t have to be made from second-life batteries and there are plenty around the world made from new batteries. But the battery supply chain is already stretched with energy storage systems competing with car manufacturers for new batteries already in short supply, second-life use adds capacity as well as sustainability. California and Australia, with their famously sunny climates, have pioneered the pairing of solar and battery power. Bernadette Del Chiaro, Executive Director of the California Solar and Storage Association said: “Energy storage is actually the true bridge to a clean- energy future.” However, these massive BESS systems, some up to 400MW/1,600MWh, are made from first-life batteries and it will be several years before second-life batteries will be available in these volumes. What makes sense for the automotive industry in the UK is an EV charging infrastructure which is based around small scale BESS. A localised system where energy is stored from solar panels in the BESS and the grid connection is managed via the BESS’s management system is the perfect solution. The dots are being connected. The UK government recently awarded National Highways £11 million to invest in energy storage for rapid motorway EV charging. We are on the road to a green energy transition and transport system. A BESS can be a cheaper and greener solution than upgrading network supplies to overcome grid constraints ”