A 560-km transmission line under the Atlantic seabed to bring home 7,000 megawatts of offshore wind power
Imagine generating enough power from the high wind blowing over the sea to meet the demands of both Mumbai and Bangalore. And laying a transmission line under the seabed long enough to cover the distance between Delhi and Manali. That is the scale of the Atlantic Wind Connection (AWC) project, which hopes to harness Atlantic winds for the US.
On paper, wind has always been a dream solution to our clean energy needs. Once installed, wind turbines generate power free. Yes, those giant contraptions are noisy, their blades are known to kill birds and bats, and a horizon dotted by rows of crowned towers can be an eyesore, but most environmentalists are sold on wind power in the era of climate change because wind energy is an option with no greenhouse gas emissions.
Yet, for many, it’s a pipedream. Critics of wind power say that windmills take up too much real estate to turn out too little power, that there just isn’t enough land available for it to make a real difference. Their bigger objection, however, has to do with the fickle nature of the resource itself. Wind, they argue, is too unreliable a solution to the global energy crisis. It is true that wind does not blow—or blow hard enough—all the time. And it is usually strongest at night when demand for power typically ebbs. Its unpredictability means that a windmill farm operates at an average 35 per cent of its capacity, against 80 per cent for a coal-fired or 50 per cent for a hydel plant. So a grid that uses wind power requires back-up that must come from fossil fuel-based plants.
All these are valid objections. But wind power has attracted interest and investment ever since 1887, when James Blyth, a maths professor, designed and built a wind turbine that lit up his Glasgow home. In the 1970s, even NASA started exploring the commercial potential of wind energy. Then, in 1991, the world’s first offshore wind turbine came up in Denmark and promised to answer the difficult questions often asked of wind power.
Offshore turbines have caught on in recent years. Not only is wind velocity across an open ocean much higher, offshore plants also relieve the pressure on real estate onshore. Offshore wind is usually more grid-friendly as well, picking up in the afternoon when demand for power starts to peak. It is also more consistent and helps an offshore turbine achieve 40 per cent or more of its capacity; Norway’s Hywind demo project has achieved 50 per cent.
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Wind has the disadvantage of not being a transferable source, unlike fossil fuel. Nor is it storable, like dam water. Still, a well-designed project can overcome those handicaps. Studies show that if three offshore wind sites are connected, only 2 per cent of the time would they have no power to offer at all—a baseline reliability figure thrice as high as that for fossil fuel plants.
Around 5,000 MW of offshore capacity has already been installed across the world, mainly in north Europe. While this is still only around 2 per cent of the installed capacity of wind power, a 2012 study by University of Delaware and Stanford University has estimated the global potential for offshore wind power, with 4 million turbines, as 7.5 TW (1 terawatt = 1 million megawatt), which would be over half the world’s demand in 2030.
In Asia, China, Japan and Korea have invested heavily in offshore projects. But much of the action is on the other side of the Pacific. In 2008, the US Department of Energy (DOE) released a roadmap for achieving 54 GW (1 gigawatt = 1,000 MW), a fifth of its electric energy supply, from wind by 2030. President Barack Obama has been keen on clean energy, and this has boosted US efforts. In 2010, the DOE’s National Renewable Energy Laboratory estimated that the US could generate over 4,150 GW of power offshore, more than four times what it had managed so far. This suits the US because offshore wind power is closer to its major electric load centres: 28 of its coastal states use more than 79 per cent of the nation’s electricity.
Last year has been the most ambitious so far, with wind energy generation in the US growing by a record 17 per cent, backed by $25 billion in private investment. A number of offshore projects are coming up in Massachussetts, Rhode Island, Maryland and Virginia, and even along the Pacific coast, where much deeper waters pose a critical technological challenge, for which floating foundations are being shipped from Europe.
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These strides notwithstanding, it is the Atlantic coast that could be the Holy Grail here. This swathe alone could produce enough clean electricity to power at least one-third of the entire US or its East Coast from Maine to Florida. To that end, with sponsors such as Google and Japan’s Marubeni Corp, a consortium of companies has set up the ambitious Atlantic Wind Connection (AWC) project.
This January, the AWC selected New Jersey for the first phase of its mega project, which proposes to lay a 560-km-long high-voltage transmission line six feet under the seabed about 20-22 km off America’s east coast, stretching from New Jersey to Virginia. The transmission corridor will only be around 200 feet wide, thus skirting seabed obstacles and environmentally sensitive areas. The first phase is expected to produce 3,000 MW from offshore wind turbines.
If all goes according to plan, by 2026 the AWC will produce 7,000 MW of offshore wind energy for the East Coast, enough for 1.9 million households. That will be a significant leap over the 630 MW of the world’s largest offshore wind farm right now, which is the London Array in the outer Thames estuary.
The future of offshore wind power may be even more promising than these figures suggest. By the end of 2020, total global installed capacity is projected to reach 75-80 GW, with the UK, Germany, China and the US leading the way. The industry is busy paring costs and improving efficiency. It may not be long before the ambitious AWC project is dwarfed by others. The 9,000 MW Dogger Bank project in the North Sea, 125 km off the UK coast, has already rolled in.
India’s installed wind power capacity of 19,052 MW is the fifth largest in the world. But the country is yet to tap the vast offshore wind potential along its 7,500 km coastline. The Centre for Wind Energy Technology says the southern coast of Tamil Nadu alone could generate up to 1 GW.
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