Underground Space Use for Renewable Energy Production and Storage

The use of underground spaces for renewable energy production and storage has gained increasing attention as a strategy for making cities more sustainable. Underground spaces offer several advantages for energy production and storage, including insulation properties, thermal stability, and relatively low environmental impact. This paper explores the potential of underground spaces for renewable energy production and storage and highlights some promising examples and case studies. In addition to renewable energy production, underground spaces can also be used as storage facilities for renewable energy. One promising technology is underground pumped hydro storage. Another promising technology is compressed air energy storage (CAES), which involves compressing air into underground caverns or other spaces during periods of low energy demand and then releasing the air through turbines to generate electricity during periods of high demand. The SubSpace Energy Hub initiative that was created in June 2022 in the Hagerbach Test Gallery in Switzerland offers a platform for the development, prototyping, and installation of new technologies that promote best practices in sustainable energy use and storage. The aim is to be a model ecosystem of sustainable energy storage and delivery in support of green energy use in future cities. While there are still challenges to be overcome, such as the relatively high cost of some underground technologies and the need for appropriate regulatory frameworks, the examples and case studies outlined in this article demonstrate that there is already progress being made toward creating more sustainable cities using underground spaces.