The first full-scale floating wind turbine array will be installed 20 miles south of Maine's Monhegan Island.
Orono, Maine CNN  — 

The first, full-sized floating offshore wind turbine in the United States will tower 850 feet above the waves in the Gulf of Maine – roughly as tall as New York City’s famed 30 Rockefeller Plaza.

The gigantic machine, with 774-foot diameter blades and tethered to the seabed with thick metal cables, is planned to be put into the water 20 miles south of Maine’s tiny Monhegan Island by the end of the decade. It is expected to generate up to 15 megawatts of electricity – enough to power thousands of homes – and will be just one in an array of 10 such turbines that would together produce up to 144 megawatts of clean energy.

The Maine turbine array will join the ranks of only around 20 deepwater “floaters” around the world, located mostly in Europe. Developers, government officials and experts say these floating turbines are the future of the wind energy industry and are eyeing projects that could each deliver clean electricity to 750,000 homes.

“That number is set to explode,” Henrik Stiesdal, the Danish wind turbine inventor and pioneer, told CNN. Stiesdal was the first to pioneer the three-blade turbine that has become the icon of wind energy. In a sign of the times, his company is now focused on putting floating turbines in deeper water.

Floating wind farms have enormous energy potential, capable of producing more energy than solar panels or onshore wind. A robust set of floating turbines could unlock up to 2.8 terawatts of clean energy in the future – more than double the country’s current electricity demand, US Energy Secretary Jennifer Granholm said last year.

“We now have a number of technologies that can step up to the plate and provide a very large share of electricity that is clean,” White House National Climate Advisor Ali Zaidi told CNN in a recent interview.

The vast majority of offshore wind turbines around the world are affixed to the bottom of the sea floor on sturdy foundations. But those turbines also are limited to shallower waters closer to the coast.

Pushing wind farms into deeper water means more area can be developed, and the farms themselves will be much farther away from the coast – and away from the view of homeowners.

“Most of these machines will not be seen from land,” Walter Musial, who leads offshore wind research at the National Renewable Energy Laboratory, told CNN. “They will avoid the classic visual impact concerns that caused a lot of projects to be delayed or become not very popular because they could be seen from shore.”

Stiesdal estimated that floating offshore wind could eventually supply half the power to the East and West coasts, and noted Europe has set a goal of producing half of its electricity from floating wind by mid-century.

But plenty of hurdles remain. Not only is better port infrastructure needed to build and tow the turbines out to sea, but massive transmission cables need to be built that can carry electricity back to dry land.

Even with the recent passage of a major climate law in the US, the larger offshore wind industry is facing a tumultuous time, with supply chain constraints, inflation and high interest rates – all coming as the wind industry tries to increase the number of US turbines in the water from just seven.

But Zaidi is unflappably optimistic. Floating offshore wind is an opportunity for the US “to really define the frontier,” he said, unlike other parts of the sector “where we’ve got to make up for lost ground.”

The stress test

With a flip of a switch, a wall of high-powered fans roared to life above an indoor pool at the University of Maine. In the middle of the pool, a small model wind turbine bobbed in artificial waves in front of the wind tunnel, its blades turning slowly.

A group of engineers stood next to the pool and watched intently as data started streaming in on the screen of their computer. They were simulating hurricane-force conditions to scale, testing the stamina of a wind turbine to see if it could survive 50-foot waves and wind speeds of close to 90 miles per hour.

“We’re basically measuring how much it tilts, how fast the turbine is moving,” said Anthony Viselli, the manager of the university’s offshore model testing and structural design.

Engineers test a floating offshore wind model in the pool at the University of Maine's Advanced Structures and Composites Center, which is pioneering designs of floating turbines.

The University of Maine Advanced Structures and Composites Center, where the pool is housed, feels like the most technologically advanced shop class you’ll ever see. Home to what the school says is the world’s largest 3D printer, the engineers, researchers and students here are working on a variety of projects – from developing 3D-printed homes from recycled wood products, to building light-weight bridge components that can fit into a backpack, to inflatable shields that can withstand Mars’ atmosphere.

It’s also home to the most cutting-edge testing technology for floating offshore wind in the US, a project pioneered by Habib Dagher, the founding executive director of university’s composites center. A one-stop shop for wind turbine building and testing, University of Maine offshore wind engineers put every component of large floating turbines through their paces.

In one part of the cavernous building, there was a hole in the wall where engineers inserted a full-sized wind turbine blade and used a hydraulic machine to push and pull it for months at a time to simulate the stress brought by years of high wind speeds.

“Basically, you take the damage that you expect from wind, and you accelerate the damage,” Dagher said. “We ask ourselves, how long is it going to last? If you take a paperclip and bend it back and forth, eventually it snaps. We’re doing the same thing.”

Back at the pool, Todd Griffith, a mechanical engineering professor from the University of Texas Dallas, was standing near a model prototype of what’s known as a vertical axis wind turbine – a turbine that looks like an eggbeater.

Griffith had traveled from Texas to Maine specifically to use the facility’s unique tools as part of a multiyear research project on another, lesser-known form of offshore wind that could be used in floating projects in the future.

“We all can agree we’re having a lot a lot of fun,” Viselli said. “You’re working on technology that can have huge societal effects and job creation. It’s just checking all the boxes. It’s not many problems where you can touch all those meaningful things and really sink your teeth into a great engineering problem.”

A floating offshore wind model turns in front of a massive wall of fans at the lab, as the indoor pool simulates waves. The wall of fans is designed to replicate hurricane-force winds.

‘The Biden boost’

Maine researchers are getting closer to putting their large prototype into the water, but commercialization is still several years away.

European companies are moving faster. Scotland has had a floating wind farm demonstration up and running since 2017, and the country wants to install an over 3-gigawatt project. Norway is also planning more floating parks in the water before 2030 that could generate the same amount of electricity.

Still, no commercial projects on a gigawatt scale have yet been built. Dagher told CNN he believes the international race to commercialize offshore wind is “up for grabs right now.”

Three of the seven only offshore wind turbines in US waters at the Deepwater Wind project near Block Island, Rhode Island.

But the Europeans are watching what’s happening in the United States with high interest; all the more surprising given how far the US lags when it comes to shorter, bottom-fixed turbines. There are just seven turbines total in the US, although several projects are being constructed or undergoing environmental review.

“I think the US has all the cards in their hand,” Stiesdal told CNN. “The US has immense offshore wind resources. If it puts its sights to it, it could become the leading country on floating offshore wind.”

California and US floating offshore wind are often mentioned together. The state’s coastal waters are too deep for conventional turbines, and California recently held its first floating offshore wind lease sale. Other offshore leases are expected in the future off the coast of Oregon and the Gulf of Maine – near where Dagher’s team is launching their test turbine.

Arne Vatnøy, the spokesperson for trade group Norwegian Offshore Wind, called the recent flurry of activity on US offshore wind “the Biden boost.”

“That’s how we view it,” Vatnøy told CNN. “A change in how people talk about the US and offshore wind in the same sentence after Biden.”

A small-scale floating offshore wind demonstration designed by University of Maine engineers sits in the waters off the coast of Maine. Launched in 2013, this grid-connected turbine has been gathering data to see how larger floating turbines would fare during storms in Maine's coastal waters.

There are still significant challenges; beyond the permitting, cost, and electricity transmission constraints that many wind projects are facing, floating wind will require updated infrastructure at America’s ports and massive ships that can tow and assemble the turbines at sea. Dagher readily admits that he’s not sure whether the US can accomplish Biden’s goal of 15 gigawatts of floating offshore wind by 2035.

But Dagher, who has been working to develop floating wind turbines for over a decade in Maine, said the momentum is undeniable.

“People questioned our sanity,” Dagher said with a laugh. “Even the Department of Energy questioned our sanity 15 years ago.”

Now, he has the enthusiastic backing of the Department of Energy and the White House, plus an entire industry eager to turn the designs into floating energy powerhouses.

“The US has a goal of 15 gigawatts of floating by 2035,” Dagher said. “So, we’ve got a little over 10 years to get there.”