Who’s Gonna Win The Race For Floating Offshore Wind Turbines, Maine Or California?

December 23rd, 2019 by Tina Casey

California is used to grabbing the clean tech spotlight with its massive onshore wind farms, but it looks like Maine could nail down bragging rights to the nation’s first ever floating offshore wind farm. The problem is that Maine already has 75% renewable electricity and it can barely stuff any more wind power into its grid. So, what’s the point of building new wind offshore wind farms in Maine, floating or otherwise?

Full Steam Ahead With Floating Wind Turbines

We’ll get to that grid system thing in a minute. Meanwhile, Maine has been eyeballing its offshore wind resources for a while now, and it is looking at floating offshore wind turbines because, well, they float.

That means they can be located farther offshore, where winds are more optimal and the chances of bumping into people and boats are reduced.

Wind fans in Maine suffered a disappointing blow back in 2014 when former Governor Paul LePage ixnayed a gigantic offshore wind proposal from Statoil, but he did greenlight a more modest floating wind turbine R&D project involving the University of Maine’s 1/8 scale VolturnUS floating wind turbine prototype, spearheaded by the firm Maine Aqua Ventus.

A generous grant from the US Department of Energy sweetened the pot, and now it looks like all that hard work is about to pay off.

Last week, the Central Maine Power Company announced itself as the anchor buyer of electricity from a full scale floating wind farm developed by Maine Aqua Ventus, under a power purchase agreement.

When Will These Floating Offshore Wind Turbines Happen?

The 20-year agreement will kick in when the floating wind farm begins commercial operation.

That could take a while, or maybe not. The site for the new floating wind turbine project is already a designated offshore wind test site established in 2009, about 3 miles (5 km) south west of Monhegan Island and 12 miles (19 km) off the coast of Maine.

Aqua Ventus and UMaine have also been working with wildlife conservation stakeholders in the area since 2010.

Use of the so-named UMaine Deepwater Offshore Wind Test Site is limited to two wind turbines, both of which appear to be claimed by the Aqua Ventus project. The two floating wind turbines will come in at 6 megawatts each, for a total of 12 megawatts.

Both turbines will be situated on the MW turbines on VolturnUS, a floating concrete semi-submersible hull designed by UMaine.

Maine’s wind industry is relatively small but apparently the project already has a supply chain in hand. Plans include fabricating the turbine platforms and columns in Brewer, where an existing industrial facility is located. The adjacent Penobscot River will provide the means to tow the parts to the hull, which is stationed in Searsport. From there everything will be towed out to the test site.

Completing the project is a cable connecting the two turbines along with a 34.5 kilovolt subsea power cable.

Still up in the air is what to do about the onshore transition site. CleanTechnica is reaching out to the developers for an update, so stay tuned for more on that.

Okay, so 12 megawatts is kind of shrimpy compared to other offshore wind projects. However, if all goes according to plan, the two floating turbines at the test site will set the stage for further development.

Floating Wind Turbines &… Wait, A Floating Concrete Hull?

If and when that all happens, give a shoutout to US taxpayers. In addition to previous Energy Department grants, last September UMaine won a $1.4 million award from the agency’s ARPA-E cutting edge funding arm to deploy NASA’s vibration-reducing technology on its ultra-lightweight concrete hull and optimize the hull for stability.

The National Renewable Energy Laboratory also won $1.5 million in funding to collaborate on the project.

The aim is to improve turbine performance and reduce costs. UMaine describes the approach as a revolution in floating offshore wind turbine design.

“The proposed technology is a departure from current floating concepts and achieves a significant LCOE [levelized cost of energy] reduction, even when using standard wind turbine architectures,” UMaine explains.

Building Electrification & Floating Wind Turbines

So, here’s where it gets interesting. According to the latest stats from the US Energy Information Agency, about 75% of Maine’s electricity generation is from renewables, including 31% hydropower. Wind, biomass, and natural gas each account for about 20% more or less.

It may seem that Maine is doing pretty good on the decarbonization front, but that’s just for power generation.

The big problem for Maine is that petroleum still provides a big chunk of its fuel for heating buildings. In fact, petroleum sucks up about 50% of the state’s overall energy consumption.



Considering the petroleum angle, and the potential for more wind energy, Maine is tailor-made for the building electrification movement. However, its transmission system is already stretched to the limit, and a major overhaul would be prohibitively expensive.

The good news is that electricity stakeholders are beginning to looking energy storage as an affordable alternative. The idea would be to keep wind turbines running at night when demand is low, and store the excess power until needed.

Lithium-ion batteries are just one option. Power-to-gas fans have been pitching their hydrogen based energy storage technology to Maine policy makers, and a new “liquid air” energy storage facility planned for nearby Vermont could pique their interest as well.

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Photo: floating offshore wind turbine courtesy of Maine Aqua Ventus.









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