As a new type of mechanical energy storage, gravity energy storage is expected to usher in the first year of technical verification in 2022.
The so-called gravitational energy storage is a kind of mechanical energy storage, which uses electricity to lift heavy objects to a high place to increase their gravitational potential energy to complete the energy storage process.
Before 2019, gravity energy storage was mainly a theoretical concept, and after a two-year technical trial period, it is expected to enter the early stage of industrialization in 2022.
After preliminary inspection of the preliminary project, the two leading companies in the global gravity energy storage field, Energy Vault (hereinafter referred to as "EV") and the Gravitricity gravity energy storage project, are expected to take the lead in commercialization in 2022.
The 100MWh gravity energy storage demonstration project in Rudong, Jiangsu, China, under China Tianying, which has obtained EV technology authorization, is expected to be put into commercial operation in July 2022. This is the world's largest gravity energy storage project and the world's first 100MWh scale gravity energy storage project.
Advantages and disadvantages of gravity energy storage
Compared with the current mainstream pumped hydro storage and lithium battery energy storage, gravity energy storage has the advantages of small footprint (mainly using space in the height direction), high conversion efficiency, relative safety (no explosion, dam failure risk), and storage time. Long (gravitational potential energy maintains theoretically infinite time and there is no loss) and other advantages.
According to the different deadlines of energy storage, gravity energy storage at home and abroad has further proposed two types of gravity energy storage technology routes: water quality type and solid heavy object type.
From the comparison of various gravity energy storage performances, the water-medium gravity energy storage system is inferior to the traditional pumped storage energy storage system in terms of power and energy storage capacity, but has a shorter response time and more flexible location selection, and the underwater energy storage system can be reasonably utilized. In the ocean space, the piston pump system can provide energy storage services for cities, and the cost and efficiency of energy storage are also comparable to those of pumped hydro.
The energy storage capacity and power of the solid heavy object gravity energy storage system are ranked from large to small: based on the mountain drop system > based on the underground shaft system > based on the structure system. Since the solid heavy-object energy storage system does not need the structure of pumps and turbines, it can theoretically achieve higher energy storage efficiency than pumped storage, and the response time is also shorter. Different energy storage structures can be flexibly selected according to different terrains and needs.
From a global perspective, the overall application of the gravity energy storage industry is still in its early stages, and the technical feasibility and economics of 100-megawatt applications remain to be verified.
At present, there are not many start-up companies in the global industrialization of gravity energy storage, mainly EV companies in Switzerland, Gravity Power in California, Gravitricity in Scotland and other companies, but the most noteworthy is EV companies, which have achieved SPAC listing. .
EV, established on January 1, 2017, is a Swiss-based developer of renewable energy storage technologies and products. It has completed financing in Duolun, among which it received US$110 million from SoftBank Vision Fund and Saudi Aramco Energy in 2019 and 2021, and launched the first energy storage pendant product EV1.
EV proposes a gravity energy storage power generation solution based on concrete block energy storage towers, with the goal that the cost will be half the cost of existing grid-scale battery energy storage solutions.
