Renewable energy sources are increasingly present on the Belgian ground for eletricity production. However, they require energy storage solutions for periods without sun or wind to power up the grid. The Sink Float technology consists of using concrete masses that are shifted across large depths underwater, from 40 to 4000m deep, where their varying potential energy will make possible the storage or restitution of the excess or lack of produced energy, respectively. The overall system is merely composed of durable and robust components such as concrete, steel cables, a hoist system, a barge, and floats. The concrete blocks will be stored at 40m underwater, to make their position and stability unsensitive to exceptional weather conditions.
The Sink Float solution, connected to a renewable energy source on the coast, can be up to ten times cheaper than the presently used energy storage systems (batteries and pumped hydroelectricity stations), depending on the distance between the offshore station and the renewable energy, where long transmission cables are expensive and subject to losses. Moreover, the Sink Float system capacity can be up- or downscaled without constraints, since it is only a matter of adding or removing concrete blocks to the system. This system would provide a clean and low-cost energy storage solution to make possible a totally renewable-energies coverage around the world.