Offshore Wind: Change is in the Air
Underdeveloped in the US so far, offshore wind stands poised to take off. However...
In my last article Heavy Metal: Rockin’ Old 26Fe, I discussed iron-air batteries and their potential role in storing renewable energy, an essential leap if we’re going to transition to an all electric power grid (or as close as possible). Another critical area of development lies in offshore wind, including installations where this was previously impossible with new floating platform design. To date, offshore wind turbines have been limited to a water depth of about 330 feet (100 meters), the limit of fixing permanent structures to the ocean floor and thus far, in the US at least, only deployed at small scale on the Atlantic coast. However, design and testing of floating wind turbines has been underway for a decade and edging closer to manufacturing and deployment which could enable installations in far deeper waters, most significantly those of the Pacific Ocean.
Currently, there are over 72,000 land-based utility scale wind turbines on US soil, enough to power about 39 million homes. Offshore wind has been extremely limited, with just those two installations on the East Coast, however, huge expansions are proposed for Atlantic waters. Existing installations include Block Island Wind with a modest 30 megawatts of capacity, five turbines 3.3 miles off the coast of Rhode Island that can power 17,000 homes and Coastal Virginia Offshore Wind, a two turbine 12 megawatt project that can power 3,000 homes, essentially a demonstration project.
Proposed Ocean Wind Farms
In an effort to expand offshore wind power, the US government is leasing 30 gigawatts of federal waters by 2030 (enough to power ten million homes and avoid 78 million metric tons of CO2 emissions according to the Biden administration) and an additional 15 gigawatts of offshore wind by 2035 which would provide power for another five million households. These plans include fifteen proposals in the Atlantic with a couple of thousands of installations that would cover over 1,200,000 acres of ocean floor, projects ranging from 183,353 acres to 26,332 acres. These leases are under contract, with project completions ranging from 2023 (obviously beyond questionable as the end of the year approaches) to 2028.
In Lake Erie, the Icebreaker Wind project off the coast of Cleveland is a proposed demonstration that would power 7,500 homes. The US Department of Energy says that the Great Lakes collectively have the potential to provide 700 gigawatts of offshore electricity, enough to power millions of homes.
The Pacific and Gulf of Mexico coasts are also targets of development, with five leases offered off the coast of California, about 373,000 acres, and in the Gulf with three leases offered, but only one selling this past August.
Floating Platform Wind Turbines vs. Fixed
To date, US ocean wind installations have been small and limited to the Atlantic. Because of its relatively shallow offshore depths, fixed floor designs have been used. The depth of the Pacific exceeds the engineering capabilities or realistic cost of using fixed floor technology, making the advent of floating platform design in testing for ten years key to establishing west coast ocean wind power.
Fixed floor designs include:
Gravity-based foundations: site depths up to about 100 feet (30 meters)
Suction bucket foundations: site depths up to about 100 feet (30 meters)
Monopile foundations: site depths up to about 160 feet (50 meters)
Tripod foundations: site depths up to about 160 feet (50 meters)
Jacket foundations: site depths up to about 200 feet (60 meters)
Jack-up: site depths up to about 330 feet (100 meters)
Like all energy technology, “green” wind power carries serious environmental costs. Specific fixed ocean platforms involve varying operations that are detrimental to marine life. Dredging to prepare the sea bed floors for foundations and cables, vibrations from drilling and pile driving, the large footprints of some designs, and invasive species introduction when towing foundations and components from port to site are all issues. Installation noise can disorient, injure and kill marine life sensitive to pressure waves including humpback whales, loggerhead turtles and manatees, and the inherent vibration of these massive structures in operation can be an ongoing issue. Our oceans are already filled with man-made noise including military sonar (I once wrote letters to the Secretary of the Navy on this issue, predictably to no avail), believed to often drive the beaching of whales and dolphins. Necropsies revealed burst ear drums.
These machines are massive, but I will go into more detail on that shortly. Back to floating platforms, the design poised to open up the Pacific and deeper waters of the Atlantic to thousands of wind turbines.
Floating Platform Advantages
Floating platform foundations can be installed at depths of up to 720 feet (220 meters), but the word installed is a bit of a misnomer, because their design means they can be towed to sites where wind is prevalent and impacts on wildlife can be reduced. Whether we prioritize ocean life and the migratory patterns of birds and flights of bats over optimal wind conditions is an open question. After all, our self-centered activities have caused the 6th Great Extinction, the loss of species far faster than at any other time on Earth. That said, disturbance of the seafloor is minimized as just three tethered anchor points are required. Construction can be accomplished onshore, also reducing cost and environmental impact. Used properly, this design could be benign compared to fixed platforms. Of lesser consideration, these wind farms can also be placed far enough away that we don’t have to see them. Personally, I think we SHOULD see them. We should be constantly aware of our consumptive lifestyles impacts on the planet.
One of the developers, designers and researchers of floating platform technology is Habib Dagher, the executive director of University of Maine’s Advanced Structures and Composites Center, which over ten years ago launched VolturnUS, a 1/8 scale 20 kilowatt wind turbine model off the coast of Castine, Maine where it survived a brutal winter for over a year, never tilting more than 5 degrees. Mr. Habib states:
“Within 50 miles of the US coasts—both east and west coast—there’s enough offshore wind capacity, theoretically, to power the country four times over.”
The Scale and Resources Wind Turbines Demand
The average height for offshore wind turbines in the US, 330 feet (100 meters) in 2016 is projected to grow to 500 feet (150 meters) by 2035. The widely used GE 1.5 megawatt model has 116-foot blades atop a 212-foot tower for a height of 328 feet. The blades sweep a vertical airspace of just under an acre. A larger model being seen more now is the 2-megawatt Gamesa G87 from Spain, with 143-foot blades sweeping 1.5 acres on a 256-foot tower, totaling just under 400 feet. Those blade sweep areas traveling up to 160 miles per hour give some clue as to the lethality to birds and bats, particularly in dim, foggy, or even smoky conditions given the massive fires now routine all over the globe.
As for weight, the GE 1.5 megawatt model, the nacelle alone — the cover that houses the components — generator, gearbox, drive train, and brake assembly weighs more than 56 tons, the blade assembly weighs more than 36 tons, and the tower weighs about 71 tons, a total of around 164 tons. The Gamesa G87 is twice as massive at 334 tons, and in the near future that won’t be big.
On land, the steel tower is anchored to a platform of more than a thousand tons of concrete (concrete itself is a major source of greenhouse gas emissions) and rebar, 30 to 50 feet across and 6 to 30 feet deep. On mountains, the tops must be blasted to create a level area of at least three acres. Further details are available here, at the National Wind Watch.
Land transport is another issue. Getting wind turbines to the site with components hundreds of feet long often requires widening roads, straightening curves, or even building new roads in wild areas. What’s the carbon footprint of mining the needed ore, manufacturing, transporting and installing these machines as we watch tipping points teeter? It’s possible the Amazon has already gone over.
My feeling? While the technology being rolled out and deployed is impressive, and no doubt the engineers and workers making these projects happen heroic and sincere, wind and solar which should have been implemented decades ago now represent last minute desperation. The speed with which we are trying to head off this unfolding disaster will bypass careful environmental studies which will lead to unforeseen consequences. These technological Hail Mary's ignore the two fundamental problems we have — overconsumption by the favored few and overpopulation by the countries left behind and persecuted by developed nations' greed. Even if we “advanced” nations get our carbon and methane problems under control, unless poor nations are given equal access to the same tools, we will fail. Instead, we continue to sell them oil. Global temperatures will continue to rise, drought and severe weather events will happen with more frequency and the human tipping points of water shortages and crop failure already locked in, will be be made far worse. In the meantime, call your broker. There’s a killing to be made. Invest in Omala S5 Wind 320 Shell gear oil. You can always count on oil.
Tidal power looks very interesting. It's being used to some degree in Europe. I'm not crazy about windmills and battery storage. Lithium mining is heinous, and the windmills have downsides, too. For better or worse, this is some of the technology we're pursuing, so I wrote about it.
Here's one about lithium mining. https://geoffreydeihl.substack.com/p/showdown-at-thacker-pass
And here's one about iron-air batteries. https://geoffreydeihl.substack.com/p/heavy-metal-rockin-old-26-fe
Of course, all mining is horribly destructive. We're missing the low-hanging fruit. Whatever happened to the word conservation? What about encouraging good urban planning and walkable neighborhoods? Why EVs instead of clean mass transit? Money and politics, of course. What we really need is a complete societal makeover, and what we are doing (entirely inadequate) should have been happening decades ago.
Tidal power is the sensible solution for America’s coastline. The last thing we need is another industrial complex.