SeaTwirl : Bearing order for S2x placed

SeaTwirl has placed an order for the roller bearing that will be in S2x. Designing for offshore conditions from the start, has allowed the cost to be lowered significantly.

The bearing is a key component in all wind turbines, whether they have a horizontal axis or a vertical one like SeaTwirl. In traditional vertical axis wind turbines that were developed for onshore use, the bearing (sometimes two bearings) has carried the whole turbine weight. It also had to carry the load from the bending moment produced by the wind.

A simple way to illustrate that load is to imagine a tall slender box on a sandy beach. As long as box just sits squarely on the ground, the sand underneath does not move. But if the box were to be tilted one way, as happens when the wind blows, the sand will move. In traditional VAWTs, the bearing must be dimensioned to withstand these significant loads, which increase the cost.

"With the sizes we are talking about now, 1 MW, the roller bearing would have been a challenge for a traditional design. With our solution, the bearing will have an even and relatively low load from the generator housing as the water carries the weight of the turbine and bending moment from the wind. That lowers our component cost significantly," says Andreas Oscarsson, head of bearings at SeaTwirl.