Researchers from North China Electric Power University, the China Electric Power Research Institute, Xi’an Jiaotong University, and King Abdullah University of Science and Technology in Saudi Arabia have proposed converting wind turbine towers into gravitational energy storage systems. According to their calculations, the new technology is capable of reducing grid frequency deviations by 16%, lower wind-induced tower oscillations by 62%, and, provided it operates under ideal conditions, extend the tower’s calculated service life by nearly 50 times. Moreover, no separate structures need to be built – the storage system may instead utilize the existing turbine tower.
As the share of wind and solar generation increases, power systems become less stable. Unlike conventional thermal and hydroelectric plants, modern wind turbines possess almost no inherent mechanical inertia to help smooth out sudden frequency fluctuations in the grid. Today, battery storage systems are increasingly used to address this issue, but they are expensive, degrade progressively due to frequent charge-discharge cycles, and require replacement after several years.
The researchers proposed utilizing the existing wind turbine structure. A heavy mass weighing several tens of tons is placed inside the tower and connected to a motor-generator. When there is a surplus in the power system, the motor lifts the mass upward, storing potential energy. When power is lacking, the mass descends, rotating the generator and returning electricity to the grid.
At the same time, this mass functions as an active dynamic damper. The same principle has long been used in skyscrapers, where massive counterweights help reduce building sway under strong winds. In a wind turbine, the mass moves in a manner that compensates for tower oscillations and reduces structural loads.
To validate their concept, the researchers modeled the operation of three turbine types with capacities ranging from 300 kW to 10 MW, as well as a 30-turbine wind farm with a total capacity of 101 MW. The calculations used real-world wind speed data, allowing performance to be assessed under natural turbulent conditions.
Computer modeling showed that the technology works effectively on both small turbines and large wind farms. Across all models considered, it reduced grid frequency deviations by 11–16%. For a reference 10 MW turbine, the calculations also indicated a 62% reduction in tower oscillations and a nearly 57% reduction in accelerations at the tower top.
The system is not intended for long-term storage of large energy volumes. For a 10 MW offshore turbine, for instance, such a storage unit can store about 12 kWh of electricity, roughly the same capacity as a home battery system. Its primary role is therefore not to replace industrial-scale energy storage, but to respond rapidly to sudden frequency changes and thereby enhance power system stability.
Another advantage of the technology is that it eliminates the need to build dedicated gravitational storage facilities. Unlike most such projects, which require purpose-built towers, mine shafts, or mountain slopes, the new system uses the existing wind turbine tower. An emergency mode is provided for extreme weather conditions: in very strong winds, the mass automatically descends to the tower base and is locked in place to avoid imposing additional loads on the structure.
The researchers estimate that, in the future, turbines with a total capacity of around 200 GW worldwide could be equipped with such a system. In that case, they could provide grid inertia support comparable to that currently supplied by about ten large coal-fired power plants, although the amount of stored energy would remain relatively modest.
