The HIGREEW project has demonstrated how aqueous organic electrolyte-based redox flow battery can be an alternative for large-scale stationary energy storage applications, aligned with Europe’s main roadmaps towards climate neutrality by 2050.
The HIGREEW project addressed the challenges of developing a sustainable, low cost, and safe advanced redox flow battery technology. This have been demonstrated by the achievement of the following objectives:
1. To develop and optimise the aqueous organic electrolyte-membrane-electrode tandem and high energy density electrolyte have been studied and formulation proposed. The targeted key results specific to electrodes have been achieved with the identification of materials showing charge transfer kinetic >1x10-3 cm/s for the electrochemical conversion of HIGREEW electrolytes.
2. To design, build, test, and validate efficient Aqueous Organic Redox Flow Battery (AORFB) cells and stacks. All steps completed, tested and validated.
3. HIGREEW prototype engineering and validation in pilot facilities. Design has been completed according to operational and safety needs. Temperature control system has been added to the design consisting of heat exchangers, recirculating cooler, fans, and room air conditioning. Building and testing completed.
4. Demonstrate the use of Aqueous Organic Redox Flow Battery through the integration of renewable energy sources. The HIGREEW prototype has been successfully integrated and demonstrated in SGRE facilities in La Plana (Spain), validating the use of the prototype in the renewables plan.
5. Ensure the safety and sustainability of the HIGREEW technology: A Hazard and Operability (HAZOP) and a Structured What If Technique (SWIFT) studies have been done to understand the behaviour of the battery when it is operated outside its normal operating conditions and for the installation in the hybrid renewable plant (La Plana). Recommendations have been implemented at design stage and safety protocols defined for installation, operation, maintenance and dissemble of the battery. Information on the production and durability of materials has been collected.
HIGREEW project has proven that redox flow batteries can be a suitable alternative for stationary storage applications. Thanks to their ability to store large amounts of electrical energy for extended periods and release it quickly they can offer new solutions for renewables integration, aligned with European political drivers.
The EU has defined two cornerstones to achieve a sustainable economy, climate-neutral: The European Green Deal and the SET-Plan (European Strategic Energy Technology Plan).
On one hand, the Green Deal establishes that by 2030 the targets to achieve are:
• At least 40% cuts in greenhouse gas emissions (from 1990 levels)
• At least 32% share for renewable energy
• At least 32.5% improvement in energy efficiency
On the other hand, the SET-Plan defined that by 2030 stationary energy storage must reach 0.05€ /kW/h/cycle, 10.000 cycles, and 20 years of life.
Redox flow technology developed by HIGREEW project has successfully contributed to the deployment of the European Green Deal and SET Plan objectives.
