The next generation of renewable energy coming soon will be 10 to 20-MW wind turbine generators (WTG’s), direct-drive designs that have been freed from the depth constraints of conventional bottom-mounted offshore wind farms thanks to floating foundation substructures. The wind industry has finally entered its most productive phase by producing a turbine that can tap a vast area of the most productive wind available in the world. What’s more, the power produced will be less expensive than that from new coal, gas, or nuclear plants.

This new capability aligns itself with the offshore goal of the U.S. Government which has suggested installing install 86 GW of capacity at sea by 2050. According to the Global Wind Energy Council, that figure is six times the capacity now in place worldwide.
Fifty percent of this capacity will serve our largest population centers that live within our coastal areas. According to the American Wind Energy Association (AWEA), this new energy will eventually enter the U.S. grid eliminating the existing coal, gas, and nuclear plants that now occupy a large part of the U.S. shoreline.
Four keys to harvesting good wind
The intent of this article is to describe the components that make Good Wind good. The first will be the wind itself. The second is the 10 to 20 MW Direct Drive class of platforms Wind Turbine Generators (WTG’s). (Two are likely to be announced next year and more will follow.) The third is the floating foundation substructure supporting these WTG’s. The fourth and final item is how the connection to the U.S. grid will be made.
The first component: Good wind
The wind on land is not what we would call Good Wind because it is not that strong or steady. The wind over land also suffers from aberrations from the hills, valleys, and man-made structures. The wind developers want is the Good Wind offshore that is on average 40% faster and more consistent than on land.
The potential clean energy produced from this Good Wind is directly proportional to the cube of the wind speed, according to the Bureau of Energy Management (BOEM). What this means to the developer is that a small increase in wind, of a few miles per hour, can produce a significantly larger amount of electricity. Put another way, a wind turbine offshore working in an average wind speed of 16 mph could produce 50% more electricity than a turbine working in wind averaging 14 mph.
The second component: 10 to 20 MW direct drive WTG
The direct drive 10 to 29 MW turbine will eliminate the most maintenance intense wind turbine component – the huge and heavy gearbox. This reduces weight aloft and improves performance while reducing operation and maintenance (O&M) cost. These new WTG’s would be mounted on floating foundations in water depths that make bottom-mounted turbines impractical.
These new 10 to 20-MW turbines, coming online soon, will stand roughly 60 stories above the sea, turning rotors with 660-feet diameters. That is two football fields including the end zone. However, when viewed from the shore they will appear the size of a dime. The major manufacturers of these turbines components are positioning their plants so their output is loaded directly onto vessels because such components will be too large and heavy for land transport.
The third component: A floating foundation
This floating substructure supports the WTG and is constructed on one end of a large Ocean Going Deck Barge (OGDB) tied to a quay in the harbor. The WTG is assembled at the opposite end of the OGDB and commissioned, ready for mating with the substructure at sea. No expensive heavy-lift equipment is needed because the OGDB construction and deployment method uses air and water for final assembly of the WTG on top of the substructure after it’s launched and positioned from the OGDB (The barge and process are described here: https://goo.gl/Sz04s9). The completed floating turbine is then fixed to its station-keeping equipment (cables and anchors) in the wind farm.
The fourth component: A grid connection
For years, grid managers have been reluctant to rely entirely on wind generated from land-based turbines alone. That has now changed with offshore wind balancing the variable generation rates with high-tech battery substations. The long-sought vision of large-scale electricity storage is available today. Substations in California, Australia, and elsewhere have proven that wind industry supply storage works.
Final thoughts
Wind power has come into its own as the best source of renewable energy in the world. The U.S. Energy Information Administration says wind power has past hydroelectric which was previously the top renewable generator in the United States until late in 2016.

The new direct drive WTGs ensure a perfect fit for harsh offshore operating conditions while maximizing the power per tower with a deep reduction in cost. Now the new, far out (25 to 30 miles) deep-water wind farms, and mulita-billion dollar leases make increasing economic sense compared to the cost of new coal, gas, and nuclear power.