Developing low-cost energy storage systems is a central pillar for a secure, affordable and environmentally friendly energy supply based on renewable energies. A hybrid energy storage system (HESS) can be capable of providing multiple system services (e.g. frequency regulation or renewable balancing) at low cost and without the use of critical resources. Within HyFlow, an optimized HESS is designed consisting of a high-power vanadium redox flow battery (HP-VRFB), a supercapacitor (SC), advanced converter topologies and a highly flexible control system that allows adaptation to a variety of system environments. The system design enables modular long-term energy storage through HP-VRFB, while the SC as a power component ensures high load demands to be handled. The flexible Energy Management System (EMS) will be designed to perform high level of control and adaptability using computational analysis and hardware development. Within HyFlow, this innovative HESS is developed and validated on demonstrator-scale (5 kW scale) including sustainability analysis. The scope is to base the HP-VRFB on recycled vanadium and thereby reduce the environmental impact as well as the costs of the HESS. The consortium will build upon lab-scale and industrial application-scale experimental data to derive models and algorithms for the EMS development and the optimization of existing VRFB and SC components. An industry-scale demonstrator (300 kW scale) provides the possibility to test even the fastest grid-services like virtual inertia. Outputs of the project support the whole value-chain and life cycle of HESS by developing new materials and components and adding them together with an innovative EMS. The development of the above described HESS especially through the flexible EMS allows a plethora usage potentials to be assessed. This will lead to the grid integration of the HESS where the full potential of the flexibility can thoroughly be qualified and optimized for market requirements.

The energy transition has increased demand for energy storage, including long-duration storage solutions like redox-flow batteries (RFBs). But RFBs are limited by a high levelized cost of storage, due in part to inefficient electrode use and the lack of tailored RFB components. SPACER will develop high-power-density electrodes for RFBs, with a max. power density of ca. 1Acm-2 and energy efficiencies >85-90% at relevant current densities (20-30% higher than conventional electrodes). The expected cost is up to 50% less than conventional electrodes. SPACER’s approach is the use of hierarchical structures, i.e. complex multilayer materials. Work will entail: • Multiscale modelling to better understand RFB behavior and identify hierarchically shaped pore structures for optimum electrolyte and electric flow • Prototyping of the modelled structures via stereolithic (micro-), 3D printing (meso-) and textile (macroscale) techniques • Characterization of prototypes via cutting-edge imaging techniques like EPR to validate the models and electrode performance Three development cycles (micro-, meso- and macroscale) will provide insight into complex interactions and optimal material structures, and culminate in electrodes validated in mini-stacks by industrial partner PIN (TRL6). The intended applications are established (vanadium) and next-gen (HBr) RFBs. SPACER will give 17 DCs a unique skill set spanning electrochemistry, modelling, material science and cell engineering. The employability of the DCs will be further enhanced by high-quality individual training in scientific and soft skills, and structured network training units moving them from theoretical investigations toward industrial application. The involvement of 3 industrial beneficiaries and a non-funded Industrial Board, secondments in applied research and industry, and a strong training emphasis on market needs will equip the DCs with the intersectoral skills needed for a career in electrochemical energy storage.

The objective of HIGREEW (Affordable High-performance Green REdox floW batteries) is to design, develop and validate and an advanced redox flow battery, based on new water-soluble low-cost organic electrolyte compatible with optimized low resistance membrane and fast electrodes kinetics for a high energy density and long-life service. The battery prototype engineering design will be twofold: affordable balance of plant to optimize performance through advanced control strategy to achieve an LCOS of < 0.10€/kWh/cycle at the end of the project and 0.05€/kWh/cycle by 2030 and designed for recycling, to maximize the recycling of the components. The consortium is formed by 9 partners coordinated by CIC Energigune, Spanish research centre, that will be the focus on electrolyte and algorithm development to maximise the batteries life span and minimise its LCOS. The development of advanced materials will be complemented with the University Autonomous of Madrid to improve membranes performance and the French CNRS research centre to optimize the electrode. The 3 key components will be tested and validated at lab scale and cell level with the collaboration of the University of West Bohemia (CZ). The stack engineering will be developed by C-TECH, UK’s SME specialised in electrochemical and electro-heating process equipment, that will work together with Pinflow to optimize active components at laboratory scale and battery stack design. The system design and scale up to manufacture a battery prototype of 5Kw will be done in collaboration between Heights, UK’s engineering, and Gamesa Electric, Spanish large industry leader in renewables. The battery prototype will be tested and validated in the pilot plant of Siemens Gamesa -third party linked to Gamesa- located in Spain. The testing and validation will be the focus on safety-hazards, LCA and LCOS. The exploitation strategy will be led by Uniresearch, who are highly experienced in EU projects. The project will last 40M with a cost of 3,7M€.