Rapidly increasing demand for renewable energy, from grid-scale power supply to driving ubiquitous low-power devices such as in the Internet of Things, requires energy storage to buffer the variability inherent in renewable energy sources such as wind and solar. This storage means the power is available whenever it's needed, rather than just when the weather is appropriate. Current storage technologies are disadvantaged by challenges ranging from resource availability, chemical hazards and safe operation (e.g. electrochemical cells such as Lithium-ion batteries) to cost and environmental impact (e.g. pumped-storage hydro), whilst there is a huge requirement for storage capacity now and in the future.

GESPERR (Geobatteries: energy storage in the pedosphere to enable the renewables revolution) aims to store excess electrical energy from renewable energy generation in a convenient, safe and environmentally benign manner in a previously unexplored repository - the soil and sediment beneath our feet that makes up the pedosphere. We aim to achieve this by coupling production of organic molecules through electrical stimulation of microorganisms (electrosynthesis) and their consumption in microbial fuel cells when the energy needs to be extracted. Both production and consumption of this chemical 'fuel' would take place in soils or sediments in situ. The pedosphere has tremendous value as an energy store due to its huge volume and a commensurate capacity for energy storage, that it doesn't need to be transported or installed, and its ubiquity, being present almost everywhere on the planet and thus underpinning almost all infrastructure and energy sources where such a repository may be required. As a result, it has the potential to support powered devices and energy supply across the world.