A major challenge facing communities that produce and consume (prosumers) their own renewable energy is its intermittent nature according to wind conditions or hours of daylight. The answer is to couple the production with battery technology, but this is currently heavily reliant on lithium and cobalt imported from Asia. The EU-funded EnergyKeeper project designed, built and tested a novel, scalable, sustainable and cost-competitive flow battery based on organic redox active materials. “We advanced the technology of a redox flow battery (RFB) based on organic electrolytes from laboratory to prototype scale,” states Virginijus Radziukynas, project coordinator. Consortium members designed, constructed and demonstrated a metal-free 30 kW RFB with a capacity of 100 kWh in a real-life environment. “The interoperable battery management system enabled the plug and play integration of the battery into a smart grid. A newly developed smart grid control system, including advanced metering devices, allowed the reliable interaction of renewable energy sources, the RFB, electric vehicle chargers and variable power consumers,” adds Tobias Janoschka, project technical manager. At the same time, EnergyKeeper developed business models for consumers and prosumer communities with RFBs. “Their business logic was transposed to grid-in operational logic and validated at the test site. Finally, we drew up a set of recommendations for European energy policy reflecting the project solutions,” reports Radziukynas.
New materials developed
Project partners showcased the world’s first installation of a metal-free RFB in a smart grid at the ACRRES test site in Lelystad in the Netherlands. Demonstration of the real-sized battery proved that metal-free flow batteries are ready for widespread use in the realisation of modern energy infrastructure projects. The developed smart grid architecture and its communication, monitoring and control system ensured an optimal interplay of local grid controller and battery management system. “The battery technology was significantly advanced to be close to the commercial threshold as a scalable, sustainable and cost-competitive storage system,” notes Olaf Conrad, project exploitation manager. Research used a coupled electrochemical computational fluid dynamics model to enable the RFB characteristics to be predicted as a function of active material properties, electrolyte flow and current densities. According to Janoschka: “The model showed that the flow was uniform over almost the entire length of the electrodes studied and that the flow split in different cells was also relatively uniform. We also developed new organic active materials that will replace conventional battery metals.”
The use of metal-free RFBs and their interoperability in a smart grid will pave the way for industrialisation of this innovative technology, making Europe less reliant on lithium and cobalt-based batteries from Asia, as all the battery components – including the active storage materials – can be made in Europe. This will have a major positive impact along the entire manufacturing and electricity production value chain. The battery is suitable for communities wishing to exploit the energy they produce and consume and to run energy business models. “The scalable RFBs connected to low- and medium-voltage grids will increase the flexibility, controllability and storage capacity of grids for the benefits of grid operators and energy utilities,” observes Radziukynas. Collective storage communities with metal-free, organic RFBs are expected to appear in the mid-term future. “Through aggregation of their loads (battery charging) and generation (battery discharging), the communities will enter the wholesale, retail, balancing and ancillary services markets, including cross-border ones and peer-to-peer trading,” Radziukynas concludes.
EnergyKeeper, smart grid, renewable energy, lithium, cobalt, battery management system, redox flow battery