Rock caverns for storage of refrigerated and heated energy products

This paper explores the potential applications of rock caverns for storing various energy products, including refrigerated and heated products. The paper briefs about existing energy storage caverns in India, including those for crude oil and LPG and discusses the advantages and disadvantages of unlined rock caverns, highlighting their cost-effectiveness, safety, and environmental benefits. The use of unlined caverns for storing LPG and ammonia at temperatures as low as -40°C is also discussed. The paper then examines lined rock caverns, which offer enhanced containment and insulation, making them suitable for storing LNG and other hydrocarbon products at shallower depths. Pilot projects demonstrated the successful use of lined caverns for LNG storage are discussed. The paper further discusses thermal energy storage caverns, which can store hot water for district heating and cold water for cooling systems. The basic principles, advantages and disadvantages along with key design and construction aspects are discussed for both cold and hot storages. Finally, the paper presents a numerical analysis using a FEM software to simulate the thermal behaviour of rock caverns under cold and heated storage scenarios. The analysis focuses on the propagation of the zero-degree temperature isotherm for cold storage and temperature profiles with time for both cold and hot storages.