Germany's RWE uses retired lithium batteries to build a 4.5MWh energy storage system

　　Although the cycle life of lithium-ion batteries is longer than that of lead-acid batteries, but after all, it belongs to a chemical energy, sooner or later will be retired. But can't the retired lithium-ion batteries create more value besides shredding and recycling raw materials?

　　In fact, there is, and now it is very popular, the trend is firstly, a few years ago, China's communication base station construction company - China Tower, using retired ladder lithium-ion batteries to build a backup battery for communication base stations, SES Power also after this, increased the research and development of ladder batteries, found that these retired batteries can indeed bring the end customer a very cost-effective products, and The performance of these retired batteries is fully in line with customer expectations.

　　We learned that in a battery storage project deployed in the German town of Herdecke, German energy developer RWE reused lithium-ion batteries from Audi's electric vehicles (EVs) to build a battery storage system. This was indeed very surprising to the team at SES Power, as previously German engineers were very resistant to the use of retired batteries.

　　(RWE began testing and commissioning battery storage systems with secondary batteries in the field in November 2021)

　　RWE has deployed this battery storage system with a storage capacity of approximately 4.5 MWh at its Hengsteysee pumped storage power facility in North Rhine Westphalia in northwestern Germany.

　　The secondary batteries come from the Audi e-tron electric vehicle, which has a maximum range of 252 miles, and RWE said in a press release issued before the end of last year that the batteries still have about 80 percent of their capacity remaining after they are retired.

　　As battery energy storage system (BESS) components, these secondary batteries have a lifespan of up to 10 years and the lower cost becomes a major advantage compared to using brand new batteries, RWE said.

　　The project involved the deployment of a total of 60 batteries in a 160 square meter site, each weighing about 700 kilograms. The project is being deployed at a fast pace: installation of the batteries started in October 2021 and commissioning began in November.

　　RWE will begin selling the battery storage system to provide electricity services from the beginning of this year, initially for frequency regulation, which will help stabilize grid operations. It is expected that this battery storage project will be given more market-oriented opportunities and provide other electrical services.

　　Oliver Hoffmann, a member of Audi's Technology Development Management Board, said: "We are deploying this battery storage project in conjunction with RWE to demonstrate that resources can be saved through the use of secondary batteries and their intelligent integration into the grid. We are now also considering the disposal of batteries after secondary use and are accelerating effective battery recycling."

　　He added that Audi's "Electric Offensive" strategy will see the company launch 20 all-electric vehicles by 2025. The company's ambition to achieve carbon-neutral mobility has led it to actively partner with energy developers, such as RWE, to develop sustainable mobility solutions.

　　Meanwhile, RWE currently deploys about 600 MW of battery storage systems, but aims to increase that number to 3GW by 2030. the company said that in addition to deploying battery storage projects built with secondary batteries in the German town of Heldec, it is deploying nine other battery storage projects in the U.S., Germany and Ireland, while it is also exploring and researching liquid flow The company is also exploring and researching non-lithium battery technologies such as liquid flow batteries.

　　RWE has operated a 7 MW installed capacity battery storage system in the town of Heldec prior to this project, which was completed in 2018.

　　The company was also awarded a contract with the German Federal Network Agency (Bundesneztagentur) for the deployment of two DC-coupled solar+storage projects. The two energy storage projects for deployment in coal-fired power plants were awarded in an "innovation tender" by the German Federal State Tax Administration, for which projects using two or more low-carbon energy technologies at the same site are eligible.

　　Roger Miesen, CEO of RWE's power generation business, said, "We are working with Audi to test the use of secondary batteries by building a battery storage system using secondary batteries from retired electric vehicles. The experience of deploying this battery storage project will help us determine how to use such batteries economically and efficiently."

　　Secondary batteries from electric vehicles have long been discussed as a potential source for stationary energy storage systems. To date, there are not a large number of EV secondary batteries available, and the engineering required to match battery capacity at different usage levels has been cited as a barrier to adoption of secondary batteries, although this may be short term.

　　Several automakers, energy developers and integrators have deployed multiple such projects globally, most of which are located on the user side. For example, in February 2020, Connected Energy, a UK-based secondary battery energy storage system integrator, deployed a 1.2MW/720kWh battery storage system for Umicore, a Belgian multinational materials technology provider, using secondary batteries from Renault Kangoo vehicles.

　　Matthew Lumsden, CEO of Connected Energy, said at the time that the successful deployment of this battery storage project was an excellent way to build confidence in the use of secondary batteries, and the company deployed a 300kW/360kWh battery storage system in the UK using secondary batteries from Renault electric vehicles.

　　One of the largest such projects reported in the industry press to date is the deployment of a 5MW/20MWh battery storage system in Uppsala, Sweden, built using secondary batteries from BMW i3EV vehicles. Utility maker Vattenfall awarded the contract to deploy the battery storage project to Dutch system integrator Alfen in April 2020.

　　Last September, South Korean automaker Hyundai said it would install and test an electric vehicle battery-based battery storage system in the U.S. in 2022. The car company then partnered with UL to explore further adoption of secondary batteries.

　　SES Power believes that with the current trend of rapid growth in electric vehicle sales, there will be a large number of lithium-ion batteries for electric vehicles that will be retired in the near future. These retired lithium-ion batteries can be used not only in energy storage systems, but also in lighting, home backup energy systems, lead-acid battery replacements and other products, which will be a very promising market. The prerequisite for the future utilization of retired Li-ion batteries is to have professional knowledge and experience of Li-ion batteries, which SES Power believes and insists on doing.