Underground space energy storage technology

What are underground energy storage systems?

This paper clarifies the framework of underground energy storage systems, including underground gas storage (UGS), underground oil storage (UOS), underground thermal storage (UTS) and compressed air energy storage (CAES), and the global development of underground energy storage systems in porous media is systematically reviewed.

What is deep underground energy storage?

Deep underground energy storage is the use of deep underground spaces for large-scale energy storage, which is an important way to provide a stable supply of clean energy, enable a strategic petroleum reserve, and promote the peak shaving of natural gas.

Why is it important to develop an underground energy storage system?

Therefore, it is urgent to improve the efficient utilization of renewable energy represented by wind energy and solar energy and to construct an underground energy storage system, which is an important direction for promoting the implementation of the "carbon peaking and carbon neutrality" strategy and the transition to low-carbon energy.

What is underground thermal energy storage (SHS)?

SHS can be developed at a small-scale (<10 MW) above surface technology or at a large-scale system in the subsurface. Underground Thermal Energy Storage (UTES) is a form of energy storage that provides large-scale seasonal storage of cold and heat in underground reservoirs [ 74, 75, 76, 77 ].

How has China improved the underground energy storage system in porous media?

China has gradually improved the underground energy storage system in porous media, especially underground gas storage in depleted natural gas reservoirs, and the current working gas volume of UGS projects is more than 16.4 billion m 3. Thermal energy storage in shallow aquifers is widely developed, and the technology is mature.

Can underground energy storage systems be mined?

On one hand, during construction or operation of underground energy storage systems, water inflow could be so great that mining or operation would be impossible. On the other hand, in arid regions or within the unsaturated zone, absence of both capillary water and water at hydrostatic head may prevent storage within a mined cavern.