Every Fourth of July holiday, 20,000 visitors descend on Block Island, a remote community of a thousand off the US’s New England shore. In recent years, the surge put a major strain on the island’s diesel-fired electrical system, to the point where blackouts became as much a feature as the traditional fireworks and steak fry. But this year, “there were absolutely no power problems,” says Jessica Willi, executive director of the Block Island Tourism Council.
As of May 2017, Block Island is powered almost entirely by five giant wind turbines, each pile-driven 50 meters into the Atlantic Ocean seabed off the coast of Rhode Island. With a capacity of 30 megawatts, the Block Island Wind Farm is small compared to on-shore installations like the 1,548-megawatt Alta Wind Energy Center in California. But its importance to the wind industry is huge. The five turbines, with their 73-meter-long, 26-tonne spinning blades, make up the first offshore wind farm in American waters.
States up and down the Eastern Seaboard are racing to build the next offshore wind farm. New York approved a 15-turbine installation off Long Island; Massachusetts is seeking proposals to build more than 65 turbines south of Martha’s Vineyard; and Maryland energy regulators have given the go-ahead to two wind farms with a combined capacity of 77 turbines off the coast of Ocean City.
“The industry has made pretty substantial and irreversible steps towards its own health and sustainability,” says Walt Musial, manager of offshore wind at the National Renewable Energy Laboratory in Golden, Colorado. “The seeds of a market are in place right now.”
Multinational wind-energy firms have woken up to the opportunities on offer in the US — the world’s second largest producer and consumer of electricity. Large offshore developers like Denmark’s DONG Energy and Norway’s Statoil have set up shop across the Atlantic, bringing with them technology, knowhow, more capital and lower financing rates.
The US, however, still has a long way to go to catch up with Europe — where, after decades of considerable economic and regulatory support from the continent’s governments, contracts are now being signed for projects that developers anticipate will be cost-competitive with nuclear or coal energy, even without taxpayer-backed subsidies.
Economies of non-scale
Currently, Europe accounts for 88 per cent of the world’s offshore wind capacity, with its 3,500-plus grid-connected turbines in more than 80 wind farms across 10 countries’ waters — the oldest installed off the Danish coast in 1991. China, Japan and South Korea come next. The US barely registers on the map.
Nonetheless, the US Office of Energy Efficiency & Renewable Energy notes that American waters have a technical potential for more than 2,000 gigawatts of power from offshore wind, which is roughly twice the country’s current capability from all sources. How much of that can be realized remains an empirical question. Plus, the Trump Administration’s anti-renewable-energy stance could slow progress for wind and other green sources.
As a May 2017 report from McKinsey notes, Europe has come to dominate the global offshore wind sector thanks to “a maturing supply chain, a high level of expertise and strong competition.” Contrast that with the US, which still must look abroad for help with its wind projects.
For example, Deepwater Wind had to lease a Norwegian jack-up vessel to build the Block Island turbines, which helps explain why the Block Island project cost nearly $10 million per megawatt of capacity — 10 times more than comparable projects in Europe and about five times the cost of an onshore wind farm in the US. It’s no wonder then that offshore wind projects in the US continue to rely on government subsidies and tax credits.
Those public subsidies might only be needed to jumpstart the industry, though. “If there is a decision, based on policy or otherwise, to encourage offshore wind in significant ways, then there’s really no reason to believe that the kinds of cost reductions we’ve observed in Europe wouldn’t be possible in the US,” says Ryan Wiser, an energy policy researcher at the Lawrence Berkeley National Laboratory in California.
Wiser conducted a survey of 163 of the world’s foremost wind experts. The overwhelming consensus was that larger capacity and other technological improvements, combined with reduced financing rates and economies of scale, could bring down global costs for offshore wind by at least 30 per cent within 15 years.1
Experts also anticipated comparable cost-savings for floating offshore wind, a technology that involves mooring turbine platforms to the ocean floor with giant anchors and cables. Such an approach would be necessary on the US West Coast, where the continental shelf drops so sharply that turbine towers cannot be planted directly into the seabed. And while floating platforms are still in their infancy, “they’re definitely an emergent technology,” Wiser says.
First things first
Block Island wasn’t supposed to be home to the first offshore wind farm in the Western Hemisphere. In 2001, developers proposed a 130-turbine installation in Nantucket Sound off Cape Cod. But after more than 10 years of public opposition, costly litigation, government obstacles, endless impact studies and other hurdles, most stakeholders agree that that Cape Wind Energy Project is effectively dead in the water.
So, what did Deepwater Wind do right that Cape Wind’s developers did wrong?
For starters, Deepwater’s project was small, and it placed the turbines much further offshore than those proposed by Cape Wind. Although visible from Block Island, where the turbines are just 3 miles away, the machines appear as tiny specks on the horizon when viewed from Rhode Island’s mainland. That was important to avoid complaints about a ruined seascape.
Deepwater also engaged with local stakeholders from the get-go. “It boils down to having offshore wind developers who are open to having multiple community meetings and conversations to understand local values and then incorporate them into the development plan,” says Sarah Klain, a sustainability researcher at Oregon State University in Corvallis.
With these lessons learned and more investment arriving from abroad, Musial anticipates a rapid ramp-up of offshore wind projects ahead. “We’re just getting started and the next projects are going to be bigger,” he says.
The Art of Analysis
Wayne Miller combines physics and high-performance computing to optimize the electricity from wind. As the associate program leader for wind and solar power and deputy director of the High Performance Computing Innovation Center at the Lawrence Livermore National Laboratory in California, Miller builds simulations to engineer the best wind farm, yielding power gains of up to 5 per cent.
“It’s a marginal improvement over not having that capability,” Miller admits. But small differences quickly add up in the multi-billion dollar marketplace for wind power.
Miller and his team use supercomputers to study how the flow of air in the atmosphere might affect wind-farm operations. It starts with a numerical weather prediction system developed by the US government — the Weather Research and Forecasting Model. The researchers then add turbines to the mix.
The models incorporate the turbulent wakes from upstream turbines to reveal the best arrangement of towers. This depends on factors such as topography, wind conditions and the turbines themselves, which are so large offshore that they need even more spacing.
But oftentimes, it’s not physics as much as human factors that guide wind-farm design. “There are all kinds of restrictions that are completely exogenous to the optimal layout or the wind resource,” says Cristina Archer, an environmental engineer at the University of Delaware in Newark. The coastguard may not want turbines placed in shipping lanes. Marine biologists may want to minimize disturbance to underwater life. And then there are all the aesthetic considerations.
“It’s both an art and a science to make all these things work together,” says Miller.
1. Wiser, R. et al. Expert elicitation survey on future wind energy costs. Nat. Energy, doi:10.1038/nenergy.2016.135 (2016).
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