Fungal batteries for storing sustainable energy

Denmark is world leading in the sustainable energy production by wind turbines. However, cost-efficient energy storage solutions are needed for full exploitation of their potential. At present, increasing wind power capacity in Denmark does not lead to decommission of fossil fuel-based power plants because of the need for energy supply security, also at days with no wind. A promising energy storage technology is redox flow batteries (RFBs), using quinones as electron carriers. Quinones are aromatic redox compounds with two carbonyl groups serving as electron donors or acceptors. The prototypes of quinone batteries have been derived from crude oil, which unfortunately fall short of the ambition of sustainable energy production purely from renewable sources. It is well-known that filamentous fungi have great capacity for quinone production and they may have a great potential for being used in the next generation of these batteries. An RFB based on the fungal quinone javanicin has already been developed at AAU in a preliminary study, proving their potential to store energy. The exponentially growing cost-efficient access to full genome sequencing analysis has opened the possibility to mine fungal genomes for gene clusters that encode biosynthesis of new quinones. Some of these are likely much more effective electron-transport molecules than the ones known today. Furthermore, knowledge of gene sequence and structure together with newly developed genetic engineering methods, allow moving quinone production into existing efficient fungal cell factories and optimize sustainable and renewable large-scale production of green quinones. In this project, we will use this to generate a prototype “all fungal quinone-quinone flow battery” and elucidate the potential of such a solution in full-scale production systems.