Mair-Bauernfeind, Claudia; Schlemmer, Werner; Rudelstorfer, Georg; Spirk, Stefan; Stern, Tobias

Climate change and the resulting pressure to reduce GHG emissions are rapidly driving the development and implementation of renewable energy technologies. A major challenge of renewable energy, however, originates from fluctuations in energy production and a mismatch between supply and demand, compromising grid stability. A promising approach to this challenge involves the installation of large large-scale energy storage facilities, that act as buffer systems. Although, batteries are considered an essential part to replace fossil-based energy sources, their key components are not renewable or sustainable. This is particularly eminent for redox-flow battery (RFB) systems, whose key components, the electrolyte and its constituents, may pose a risk to the environment, if released. Recent emerging technologies aim therefore to replace these components by more sustainable alternatives using renewable raw materials such as lignin and materials derived from it. Lignin is a major wood component and in theory available in large quantities as a by-product from pulp and paper industries. Vanillin is such a commodity and was recently shown to be an excellent precursor for the production of a suitable electrolyte for RFBs. However, also this system has not been subjected to detailed sustainability analysis. Here, we perform a thorough analysis of the environmental and social risks of flow battery electrolytes by applying streamlined environmental and social Life Cycle Assessment (LCA). Furthermore, the potential consequences of using lignin-derived materials in storage technologies instead of thermal recovery are analyzed by consequential LCA. The results of this prospective assessment provide a general understanding of the potential sustainability risks and consequences of using lignin in energy storage technologies. The combination of methods contributes to a better understanding of applying prospective assessment methods on technologies in an early development stage.