Types, applications and future developments of gravity energy storage

In recent years, the clean and environmentally-friendly renewable energy technologies have developed rapidly. How to ensure balance and flexible output of power system has become a new challenge after all kinds of volatile power sources are connected to the power system. Among different forms of stored energy, gravity energy storage, as a kind of physical energy storage with competitive environmental protection and economy, has received wide attention for its advantages such as high safety, high cost-performance, great environmental-friendliness and strong environmentally adaptation. This paper firstly introduces the basic principles of gravity energy storage, classifies and summarizes dry-gravity and wet-gravity energy storage while analyzing the technical routes of different types of gravity energy storage. Separated into groups of dry and wet gravity energy storage, these storage shows similar features and promising advantages in both environmental and economical way. Among them, LEM-GES shows a new concept of storage and will be the target for future study. Then follows an analysis of the practical applications of gravity energy storage in real scenarios such as mountains, wind farms, oceans, energy depots and abandoned mines, and finally an outlook on the future development trends of gravity energy storage technology.