"SeaTwirl resembles a spinning top in the ocean, says (right)  CEO Daniel Ehrnberg. "Top spinning is a traditional game popular in Malaysia, India and Pakistan. The top that spins the longest time wins, often for hours.

"When scaling up these tops a 100 or 1000 times the ratio between energy storage capacity and surface area affected by friction increases 1000 times. This means that in larger scale the top or in this case wind turbine could spin for much longer time and hold much more energy. Energy that can level out the variations of renewable energy.”

The development, construction and installation of the prototype was made in cooperation and with support from Chalmers University of technology, Habasit AB, Ingeniörsfirman Myrén & Co. AB, Mekpart AB, Miltronic AB, Halmstad Hamn AB, Rexnord Industries, SP Technical Research Institute of Sweden, University of Gothenburg.

SeaTwirl uses a vertical axis wind turbine and a torus ring to enable storage capability. It rotates from the top all the way down to the generator, seen as the blue part  in figure (left), in direct contact to the water.

The only thing that is not rotating is the anchorage system and the generator axis at the bottom of the picture. This way the ocean water is used as a roller-bearing and the weight of the rotating turbine is absorbed by the water.

This means that there is no need for transmission line, gearbox and that the weight from the generator is placed where it should be, in the bottom.

SeaTwirl uses the physical law for conservation of momentum to enable the storage capacity. SeaTwirl transports fluids from a less rotationally centred position to a more rotationally centred position to rotate faster, as a skater doing a pirouette.

In this way it can store large amounts of energy at low speed and tap it at higher rotational velocity when the energy systems need it andl can in this way produce energy even if the winds have stopped blowing.

SeaTwirl could also be used by other renewable energy producers as an energy reservoir and stabilise energy systems. The SeaTwirl will in fact be more stabile the faster it rotates and the more it blows.