Subsurface Flow Batteries: Concept, Benefits and Hurdles. / Waltham, Dave; Holt, Katherine; Kuenzel, Stefanie; Basu, Anirban; Lecoeur, Nora.

In: Geol Soc Special Publication, 18.01.2022.

Research output: Contribution to journalArticlepeer-review



We introduce a novel concept for storage of electrical energy in the subsurface—storage of flow-battery electrolytes in porous rock. Flow-batteries operate by electrochemical transformations of electrolytes, rather than of electrodes, and their energy capacity can therefore be increased indefinitely by using larger electrolyte tanks. Saline aquifers may be the cheapest way to provide large-scale storage for this purpose. Storage would be within high-porosity, high-permeability reservoirs sealed by impermeable layers but—in contrast to hydrocarbon, H2 or CO2 storage—electrolytes would be trapped at the base of such formations as a consequence of their high density compared to natural brines.
Calculations show that the resulting devices may be able to charge/discharge safely, cheaply, efficiently and continuously for weeks at 100’s of MW. Hence they are a possible solution to the problem of long-term renewable energy intermittency. We discuss a range of electrochemical, geochemical, microbiological and engineering hurdles which must be overcome if subsurface flow-batteries are to become a practical technology. No insurmountable problems were found in our preliminary assessment but further laboratory studies are needed.
Original languageEnglish
JournalGeol Soc Special Publication
Publication statusSubmitted - 18 Jan 2022
This open access research output is licenced under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

ID: 44222380