It looks like a Brutalist tower — but it’s actually the world’s first giant gravity battery

The technology behind the tower is called GESS (Gravitational Energy Storage System). Its principle is surprisingly simple: store electrical energy by converting it into gravitational potential energy — the energy contained in a mass positioned at a certain height. When renewable sources such as wind or solar produce more electricity than the grid requires, that surplus energy powers motors that lift heavy blocks upward. When demand increases, the weights are lowered in a controlled way. As they descend, generators convert the motion back into electricity that can be fed into the grid.

In Rudong, the structure stands 148 meters tall and occupies a footprint of roughly 120 by 110 meters. The system has a storage capacity of 100 MWh and can deliver up to 25 MW of power, providing about four hours of electricity at full output.