American Offshore Energy (AOE) has designed the first wind turbine – the “American Turbine” – without a centre shaft. The vertical axis turbine features a lightweight structure, like a cross between sailboat masts and bicycle wheels, with a floating base made of fiberglass. The heaviest components – the bearings and generator – sit near sea level on the perimeter, where there are high surface speeds even at low RPMs, eliminating the need for rolling bearings, gearboxes and oil.
The AOE design also has no need for forgings, castings, conventional generators, or AC/DC conversions at sea, and it requires much less steel than a conventional wind turbine.
Being so much lighter, these turbines could be manufactured and launched from sites not appropriate for launching conventional floating turbines. They could be towed and serviced by existing Jones Act-compliant vessels. Constructed of fabricated steel and fiberglass, the turbines could be made of all-American materials, allowing US manufacturers to avoid waiting for materials from overseas. Drew Devitt, CTO of AOE, noted in a press release that this will help manufacturers deploy the turbines more quickly and at a lower cost.
Because the turbines will include no oil, they could be sunk in the face of a hurricane to ride out the storm just below the ocean surface. This would dramatically reduce the risk of damage, and consequently the cost for financing and insurance. The turbines could be raised after the storm by remotely releasing compressed air cylinders in the fiberglass floats.
With the bearings and generator components at deck level for service boats, general maintenance at sea would be simplified. Further, the turbines could be unplugged and towed back to port in a day by existing Jones Act-compliant tugs for maintenance, if necessary.
Design advantages also include safety features to protect both ships and birds at sea. The large surface area of the vertical wings is obvious to birds and gives strong horizontal radar reflection for maritime navigation, with no vertical reflection for aero navigation.
Devitt sees speed to deployment as the most significant of the design’s advantages. “Steel and fiberglass fabrication have relatively low capital requirements,” he said. “Combine that with low real estate costs, near the proposed wind farms, and you have a recipe for franchising manufacturing. Once the facility and tooling to make the turbines have been developed, they can be duplicated, and other manufacturing sites could pop up quickly near deployment sites. This would be a great way to help us meet our renewable energy targets and put Americans to work quickly.”