From Watts Up With That?
Materials, costs and survivability for wind turbines on massive floating platforms defy reality
Paul Driessen
The US Interior Department’s Bureau of Ocean Energy Management recently designated two Wind Energy Areas in deepwater areas off the Oregon coast. BOEM is also reviewing offshore wind energy development options for the Gulf of Maine, Central Atlantic, Gulf of Mexico, and maybe Great Lakes.
They’re part of Team Biden’s plan to deploy 30,000 megawatts of offshore wind energy capacity by 2030 and 15,000 MW of floating offshore wind energy capacity by 2035. Capacity is what the turbines could generate, when the wind is blowing at optimal speeds, perhaps 30-40% of the year.
30,000 MW is what 2,500 12-MW turbines could generate. It’s enough to meet New York State’s current peak electricity needs on a hot summer day. Add the electricity required to replace gasoline cars and natural gas furnaces and stoves, meet surging AI, data center and streaming video demands, and charge grid-scale backup batteries – and New York alone would likely need 10,000 12-MW offshore turbines.
Meeting the soaring electricity needs of all US states would require hundreds of thousands more.
BOEM nevertheless insists that “Offshore wind is a once-in-a-generation opportunity to build a new clean energy industry, tackle the climate crisis, and create good-paying jobs, while ensuring economic opportunities for all communities.”
Note to be outdone in baseless puffery, the Department of Energy extols the Administration’s goal of “decarbonizing” the entire US electric grid by 2035 and says “offshore wind is especially well-suited” for generating “clean energy.” Two-thirds of all US offshore wind potential, it says, exists over ocean areas so deep that turbines must be mounted on floating platforms anchored to the seafloor by mooring lines tied to suction piles sunk into bottom sediments.
DOE even claims it will somehow reduce the cost of floating deepwater wind energy to $45 per megawatt-hour by 2035. (That’s 45¢ per kilowatt-hour, triple what most Americans now pay.) To buttress its claims, DOE presents maps, artist’s renderings and images of floating turbine arrays.
It’s almost as though these government officials actually believe they can solve the alleged climate crisis by simply issuing proclamations, regulations, drawings, press releases and subsidies – and Voila!
Mines open, raw materials materialize, and millions of wind turbines, billions of solar panels, billions of vehicle and grid-scale batteries, millions of miles of transmission lines, millions of transformers and other technologies get manufactured and installed – affordably and with no fossil fuels, greenhouse gas emissions, toxic air and water pollutants, child and slave labor, or other evils (all at minimal cost), while endangered species and other environmental conflicts disappear (or are relegated to irrelevance) …
and cornucopias of clean, renewable, reliable, affordable electricity are rapidly generated worldwide.
It’s impolite to question fervently held beliefs in fossil-fuel-free utopias. However, a little reality is urgently needed before activists and bureaucrats take us any further down this primrose path.
12-MW offshore turbines are 850 feet tall, carry three 350-foot-long blades, and weigh thousands of tons. To date, few have been installed anywhere, none have been subjected to major hurricanes, and none have been mounted on deepwater floating platforms. Indeed, no such platform-mounted turbines exist outside the realm of concepts and ten-foot models in wind tunnels and test tanks.
The Kincardine floating turbines in the North Sea southeast of Aberdeen, Scotland are much smaller, and the strongest wind gusts recorded there were in the 83–123 mph range. Sustained wind speeds for category 3-5 hurricanes range from 111 to 157 mph and greater. Some of the worst US landfalling hurricanes reached 126 mph (Katrina, 2003) to 167 mph (Andrew, 1997). The strongest winds ever off the Oregon coast exceeded 100 mph (1962 and 1995).
Subsurface and semisubmersible structures for the smaller 2.0–9.5-MW deepwater turbines weigh 2,000 to 8,000 tons. New semisubmersible platforms for deepwater oil production can be over 30,000 tons and cost a billion dollars or more. Yet even they are probably not large enough for the monstrous 15-MW beasts that the Biden Administration, CNN and others are extolling.
Says 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…. 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” by 2030.
It’s almost impossible to conceive of the amounts of steel and other raw materials that would be needed for each of these gigantic turbines and support systems; the amounts of ore that would have to be extracted to obtain those materials; the fossil fuels required to mine and process the ores, manufacture the turbines, blades and support systems, and transport and install them; the cost to build each of them.
Based on average deposits being mined today, the 110,000 tons of copper required for 30,000 MW of offshore turbine alone would require removing some 65,000,000 tons of ore and overlying rock. That doesn’t include copper for marine cables, transmission lines, transformers and other equipment – or the other metals and minerals.
It is inconceivable that these deepwater wind turbine systems could ever recoup all the energy and costs – or offset all the greenhouse gas emissions – involved in building them, no matter how many years they generate electricity. Indeed, those years may be very short, due to violent storms and constant salt spray.
It’s equally inconceivable that they could survive major storms. As a deepwater oil production expert explained, the major unexamined issue is the enormous dynamic loads the mooring systems impart on support structures and turbines.
Floating offshore structures are designed to move on their mooring systems, to adjust for wind and waves. But if 115–160 mph winds hit the structures and equipment on their decks, they can be pushed to the limits of survivability. That’s what happened to the Mars TLP rig during Hurricane Katrina.
Some of its mooring lines (tethers) failed, the entire rig was pushed over onto its side, and the 200-foot-tall derrick snapped off and sank. Subsequent analysis found it was not the high winds that caused the failure, but the total structure’s return motion – its restorative forces or “whiplash” – as the wind speeds suddenly dropped from 126 mph, with gusts of 200 mph, to 15 mph.
Now picture 850-foot-tall turbines, with huge blades designed to catch the breezes, atop enormous semisubmersible platforms, being caught in a hurricane or other fierce storm; being pushed over further and further; until wind speeds suddenly plummet, and the turbines whiplash violently – and snap off.
That Shell Oil, among the world’s most experienced offshore oil developers, has dropped out of deepwater wind projects should say a lot about the viability of the far-fetched deepwater schemes Team Biden is promoting, to forcibly transform America’s energy and economic system.
That some companies are still in the game underscores how their risks are being forcibly subsidized and underwritten by taxpayers and consumers, who are being dragooned into these schemes by politicians and bureaucrats who likewise have no real skin in the game. Their leasing bids are plummeting, their electricity price demands soaring.
It’s time to say, “Enough! We’re going to keep our nuclear and fossil fuel energy, until you prove beyond a reasonable doubt that your alternatives provide equally abundant, reliable, affordable energy.”
Paul Driessen is senior policy advisor to the Committee For A Constructive Tomorrow (www.CFACT.org) and author of books and articles on energy, environmental, climate and human rights issues.
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