Life Cycle Assessment of a Flow Battery as Stationary Storage for a Renewable-based Energy District

Inhalt:
Germany aims for greenhouse gas neutrality by the year 2045, requiring a shift to renewable electricity. Given the country’s geography, solar and wind will dominate electricity generation introducing high volatility and new challenges for the power grid. In addition to increasing consumer-side flexibility, large-scale energy storage technologies are essential to balance the volatility of renewable power generation. In this context, flow batteries in general and particularly vanadium redox flow batteries can play a key role as stationary storage systems. They offer several advantages, notably long lifespan, non-flammability, and favorable operating costs. This paper presents a Life Cycle Assessment of a vanadium redox flow battery, focusing on its environmental impact from raw material extraction through production and use. The life cycle inventory relies on primary data provided directly by the manufacturer, and the use phase is modelled as stationary energy storage within a prospective renewable-based energy district. Results for the manufacturer-specific stack design indicate a significantly lower environmental impact (Climate change kg CO2e/kW = 53) compared to stack designs reported in previous Life Cycle Assessment studies of vanadium redox flow batteries (Climate change kg CO2e/kW = 327–765). The complete battery system for stationary storage applications results in 87 g CO2e/kWh, placing it within the mid-range of comparable lithium-ion batteries (Climate change g CO2e/kWh = 50–180). Altogether, these findings highlight the potential of vanadium redox flow batteries as an environmentally favorable option for stationary energy storage in future renewable energy systems.