TOWS, Inc. aims to develop and commercialize an integrated suite of solutions to some major difficulties and costs of offshore wind.

Our solution looks like a pyramidal structure with the rotor rotating between two upwind legs and two downwind legs. The above-water structure is unusually light in weight and easy to manufacture. It will use modular construction to support the rapid onshore replacement of any damaged parts.

The core innovations are hard to see. Underwater, the floating pontoons are extremely shallow-draft (hence just 5% or 10% the weight of conventional floating platforms). And there is only a single mooring line, to encourage passive alignment to the wind, and ease disconnection for towing ashore.

This obvious-seeming underwater geometry is actually very innovative, because it causes the system to ride over waves, rather than remaining at rest while waves pass. All the loads are less, reducing weight and allowing construction of relatively thin steel. But the wave induced motions are significantly increased. 

A conventional turbine can not be mounted between the tower legs without substantial modification. And conventional turbines are engineered to tolerate only slight motions. For both these reasons, TOWS will be developing a new generation of horizontal axis wind turbine – lighter in weight, lower in cost, and intended to be easier to maintain.

Developing a novel platform, and especially a novel turbine, brings many risks. It is unlikely that even a carefully engineered system will achieve the conventional 25- or 30-year life that is currently the standard in this field. But we intend to develop, and exploit, a maintenance approach that affordably brings each turbine ashore yearly, to replace any degraded components. This is a more affordable maintenance approach than normal, allowing smaller vessels and shorter component life. It reduces the risk of innovation, since surprise damage can be replaced cheaply and quickly.