Wind Power

02 Apr 2022

U.S. Wind Energy Is Venturing Offshore

02 Apr 2022  by   
Wind farm

Capturing offshore wind in the U.S. has long been an uphill battle, with various stumbling blocks in the terrain. Objections from fisheries, skepticism from conservationists and tenuous support from tourism have all stalled development in the past decade. That is, until May of 2021, when the U.S. Department of the Interior approved construction of a sprawling wind facility several miles off the coast of Martha’s Vineyard, Massachusetts.

The project marks the first large-scale offshore wind undertaking in the U.S., and includes 62 turbines that will power more than 400,000 homes and businesses. But it almost didn’t happen. Under the Trump administration, the project’s approval halted, while broader national momentum behind alternative energy solutions slowed. The country’s only other offshore wind facility, with just five turbines spinning off the coast of Rhode Island since 2016, looked like it would not have any company for years. That site, Block Island Wind Farm, produces 30 megawatts, or enough energy to power up to 17,000 homes. After President Joe Biden took office, however, he promised a 1,000-fold increase in offshore wind energy production in the U.S. by 2030. Approving the ambitious Vineyard Wind project marks the first big step.

Construction began in November, with expectations that the 800-megawatt Vineyard Wind farm will be producing electricity by 2023. And this past February, the U.S. hosted an auction for six wind leases off the coast of New York and New Jersey. The opportunity attracted more than a dozen bidders and the plots finally went for more than $4.3 billion, signaling exceptional appetite for U.S. offshore wind.

Biden opened the West Coast to the idea in May 2021 by identifying two potential sites in California, despite prior resistance from the Department of Defense, which uses the area for testing and training. Industry leaders are also exploring leasing in the Gulf of Mexico region. In October 2021, the Biden administration announced plans to consider virtually the entire U.S. coastline for offshore wind.

Hitting the 2030 goal will create approximately 80,000 jobs in the U.S. and offset 86 million tons of carbon dioxide, according to Amanda Lefton, director of the Bureau of Ocean Energy Management. “Transitioning to a clean-energy future is going to be crucial,” Lefton says. Offshore wind, it seems, is finally poised as a meaningful piece of the alternative energy puzzle in the U.S.

With 70 percent of Earth covered by oceans, it makes sense to designate a sliver of the sea for wind capacity. But that move comes with substantial hurdles, as the past 30 years of offshore wind progress have proven. Seas are rough and unpredictable. The cost of install can be staggering. Massive turbines require giant ships for transport and construction. Still, today’s advanced technology — including blade efficiency and engineering, floating turbines, and even flying drones — place offshore wind closer within reach.

Wind Turbines

Historically, Europe had a several-century jump-start on the U.S. when it came to capturing wind.

Europeans started erecting large-scale windmills to grind grain and pump water during the Medieval Era — though versions of the technology appeared more than a thousand years earlier in China and the Middle East. In the U.S., the machine only began spreading widely after 1850, when Daniel Halladay and John Burnham built their Halladay Windmill, customized for farming in the American West.

Smaller and cheaper than the typical European windmill, the design was tailored to the agriculture needs of the plains; and within 40 years, hundreds of U.S. companies were building millions of these water-pumping tools for farms and ranches. In the 1880s, two innovators (one in Scotland and one in the U.S.) independently began adapting the technology for electricity generation. A Denmark scientist made the first significant strides in turbine technology and broader application at the turn of the century. Then steam, oil and other powerful fossil fuels flooded the energy market.

Over the past hundred years, interest in wind power has waxed and waned. It remained more costly than electricity generated with fossil fuels. The financial investments in the industry started picking up in 1970 when oil prices hit a high, which significantly stimulated the market. In the next couple of decades, Congress passed laws that required companies to purchase a certain amount of power from renewable sources and provided a tax credit to businesses that used wind as an energy source.

While the U.S. stuck to land, 30 years ago, Denmark became the first country to dip its turbines in the water. If you look at a map of the country’s wind farms today, the sea resembles a busy geometric print, filled with color-coded designations of massive offshore facilities, many already operating. The pilot project was up and running in 1991. Another 15 offshore farms have rolled out since. Neighboring countries, such as Germany and the Netherlands, have invested in offshore wind since the early 2000s, the bulk of that happening in the past decade. On a comparable map of the U.S., multiple proposed projects have popped up in the past couple years, with 17 project proposals eyeing the Atlantic Coast as of summer 2021.

“The U.S. now is where Europe was 10 years ago,” says George Xydis, an assistant professor at Aarhus University’s Center for Energy Technologies in Denmark.

As offshore wind developed in Europe, increasing concerns about conservation and biodiversity pushed engineers to build larger offshore turbines. If each individual machine was larger, it would produce more power, and sites would be less expansive. Today, a large offshore turbine can produce five times the power of an average one onshore.

In terms of the environment and social impact, offshore wind is actually easier to develop than land-bound projects, according to Xydis, an engineer by trade who also holds an adjunct position at Johns Hopkins University. While completing his Ph.D., Xydis worked in the energy industry. “There are more constraints with onshore wind,” he says.

Primarily, onshore wind requires a massive slice of land. Developers also need to avoid harming birds and mammals that already inhabit the land and air the farm will occupy. Finally, people who live nearby need to tolerate the constant whirring noise the windmills generate as well as a strobelike shadow that comes and goes as the turbines turn. (Just google “shadow flicker” for a glimpse of the controversy.)

Ocean platform

The U.S. seems to be coming around to the offshore wind advantage. In 2008, the U.S. Department of Energy declared a goal of achieving 20 percent wind energy by 2030. As of 2020, the country was at 8.4 percent, with nearly 100 percent of that coming from landbound systems.

Along with objections from the fishing industry, the U.S. military has also resisted relinquishing sea space to the energy sector, likely contributing to the delayed transition to water. With the many competing interests, the approval process for a wind project can drag on for several years, weighing the impact on the environment, recreational activities and tourism.

As the U.S. now looks to the sea, this relatively late start poses some advantages, according to Xydis. Scientists have learned from the past three decades of work in Europe. They are equipped with elements like more advanced blades than ever before and the latest knowledge on how best to place 800-ton metal machines in the ocean.

Niels Erik Clausen, associate professor at Technical University of Denmark in the department of wind energy, says constraints still exist with offshore wind after decades of progress — they are just different than those onshore. Besides the enormous economic costs of such projects, construction noise, for example, may disturb marine mammals like whales, dolphins and seals. Seabirds potentially won’t return to the area, which can harm the marine ecosystem. Back in 2014, in fact, an offshore array in the U.K. was cancelled after a decade of work on the project because of uncertainty about the survival of the red-throated diver, a protected seabird.

On the other hand, these projects pose some potential benefits to sea life. “If you’ve been snorkeling, you’ll find there’s a lot of marine life around shipwrecks. The same is true with offshore wind,” Clausen says. Some argue that the turbines can serve as artificial reefs. Others claim the ecosystem benefits because the turbines prevent fishing. Studies of Rhode Island’s small Block Island Wind Farm indicate that fish and birds have adapted to their new environments and function normally.

Flock of seagulls

To get a sense of scale for one farm, a 1,000-megawatt project could require 70 to 80 turbines covering approximately 115 square miles — that is, half of the size of Chicago. The turbines themselves are spaced far apart, with more than 1 mile between each one for large turbines. If that sounds excessive, it helps to consider that just one modern turbine blade laid inside an American football stadium would nearly touch the goal posts on both sides. The cables carrying the electricity, of course, have a much longer journey. While the turbines might be two dozen miles from shore — and in water more than 100 feet deep — the cables could run to a power station another 20 miles inland.

U.S. Bureau of Ocean Energy Management (BOEM) researchers still puzzle over how turbines in oceans affect birds and fish. They recently started trying to assess the impact through the Realtime Opportunity for Development Environmental Observations project, which conducted research when the foundation work began on Block Island in 2015. The researchers will report on other offshore wind projects as operations begin in the next several years. So far, they’ve found that during the noisy pile-driving phase of construction, the abundance of winter flounder decreased. However, other kinds of flatfish were not significantly impacted. The researchers also noted that almost immediately, mussels, sea stars and anemones began covering the submerged turbines. Future studies will add data on marine life impact and likely inform industry approaches.

If determining the ecological cost proves difficult, pinpointing the economic cost is perhaps more so: “Calculating this is super complex,” Xydis says. Factors to consider include wind speed (higher winds generate more power), financing and capital costs for structure foundations and cables, often buried under the seafloor. In an area with high wind speeds, it may take just under 10 years to pay off the investment. But, Xydis says, it can range from roughly five to 15 years to reach profitability.

Onshore wind and solar power generation costs can now compete with fossil fuels. Offshore wind costs will likely drop in the future as well, according to a July 2020 study published in the journal Energy. The study predicts that Europe will move towards developing offshore wind farther from shore, where the wind gusts at higher speeds and generates more power, thus providing more return on investment. Developers will see profit quicker, and the price of renewables should drop for the communities nearby.

As time passes, wind technology will keep advancing, says Walt Musial, the offshore wind principal engineer at the National Renewable Energy Laboratory (NREL), a federally funded research center. This includes factors such as turbine height, blade efficiency and other elements that have evolved considerably over the past two decades. By one assessment from the U.S. Department of Energy, the rotor-swept areas of turbines have increased by 570 percent since 1998.

The next phase of offshore wind, Musial says, touches on a different area: floating wind turbines. This opens access to deeper waters and potentially reduces development costs by avoiding fixed-bottom foundations. At NREL, Musial works on harmonizing hydrodynamics and aerodynamics to facilitate these more advanced farms. Although the floating industry is younger, Musial says it holds a promising future. Most European offshore wind developments as well as many planned for Asia have floating potential. “The pipeline for floating is growing exponentially,” Musial says.

Other businesses are employing technology to try to solve basic problems with wind turbine inspections. A human checking huge spinning blades can pose significant dangers. Nearthlab, a South Korean company, touts their autonomous drone technology as a safer, more efficient way to perform inspections. In the same way it has implications for onshore wind, it helps developers solve the safety inspection problem with offshore wind too.

Scientists in the U.S. are also hatching other ideas to generate power from the sea. One concept, a form of hydrokinetic power, looks to the tremendous strength of ocean swell, deploying technology at the surface of actual waves. Another type of hydrokinetic energy uses the movement of ocean currents to generate power. This involves submerged devices that spin like underwater wind turbines. Finally, scientists are investigating another avenue: offshore solar, which harnesses solar power through panels on the ocean surface.

Old turbines

When devising environmental solutions, it’s key to avoid creating new problems while trying to solve an old one. For example, at some point, engineers need to replace blades and entire wind turbines. Dumping the gargantuan metal objects into landfills isn’t exactly sustainable. Denmark-based Ørsted, which is the biggest offshore wind developer in the world, announced in 2021 that it would recycle or reuse all decommissioned wind turbines going forward. Musial says materials like thermoplastic resins can melt down and be repurposed, as one solution.

Still, countries need to step it up to meet the sustainable development goals put forth by the International Energy Agency (IEA), a Paris-based intergovernmental organization. An IEA report in 2020 found that offshore wind generation must grow. Specifically, non-European countries, which have trailed behind in offshore investment, must adopt the same advancements in the wind sector that Europe has over the past decade. Although some financial incentives exist in the form of government tax credits, more can still be done to incentivize businesses to use renewable energy, like developing binding financial agreements.

Beyond the environmental benefits, offshore wind will create new industry in the U.S. Vineyard Wind claims its first farm will generate thousands of jobs over the lifetime of the project. The company also pledged $15 million in investments to “make Massachusetts the center of the offshore wind industry.” Two-thirds of that investment will go to business, infrastructure and supply chain within the state’s offshore wind industry. They will dedicate the rest to recruiting, mentoring and training people to work in offshore wind as well as marine mammal conservation.

Pushback is, in some cases, still inevitable. To get ahead of resistance from the fishing industry, Vineyard Wind has hired a fisheries representative to work on their team. Commercial fishers may still raise objections to the Vineyard Wind project. But Lars Thaaning Pedersen, the CEO of the Vineyard Wind company, insisted that “the fishing industry and offshore wind can coexist,” at a September 2021 press conference.

And Denmark, the global leader in the industry, is not slowing down. In June 2021, Ørsted announced that it would invest more than $57 billion in renewables by 2027, about 80 percent of that going to offshore wind and hydrogen projects. The Danish government also greenlit plans to build an artificial island as a hub for hundreds of offshore wind turbines — enough to power 10 million households — complete with a hotel environment to house staff. The first phase alone, scheduled for completion around 2033, will be the size of 18 soccer pitches. This new scale sets an ambitious precedent for the U.S. and other countries venturing into the sea.


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