MIT scientists say they have found a way to increase the energy output of wind farms – The Boston Globe
Typically, wind farm operators focus on achieving the maximum efficiency of individual turbines. Each turbine has its own sensors that measure wind direction and speed, enabling their blades to spin as close to the wind as possible and capture the maximum amount of energy.
But now scientists have found that, in fact, they would be better off orienting the blades of some turbines at a sub-optimal angle to the wind, so each turbine generates slightly less bumpy wind for the turbine downwind, which is called Known as a turbulent wake. Changing the angle of the blades reduces how much the turbine disturbs the air flow to the people behind it, ultimately increasing their mass output.
If existing wind farms around the world used this method, which scientists published this month in the journal Nature Energy, the additional electricity could power the equivalent of 3 million homes in the United States and nearly a billion in additional revenue each year. dollars can be generated. For the industry, he said.
Given that wind accounted for more than 9 percent of the nation’s electricity last year, as well as a growing share of Massachusetts’ overall energy portfolio, squeezing more electricity from such renewable energy projects could make a significant difference in reducing emissions. Yes, the scientists said.
It will become even more important as the state races to reduce its emissions by 50 percent from 1990 levels by the end of the decade, as required by a law passed last year, and the Biden administration lives up to its pledge to cut wants. country’s emissions in equal amounts.
“Given the scale of wind deployment required to achieve state and federal climate goals, we need optimal wind farm performance to ensure efficient, rapid decarbonization,” said an assistant professor of civil and environmental engineering at MIT and the paper said lead author Michael Howland. , “Our method resulted in significant energy gains over standard industry operation, and importantly, it can be installed with minimal cost.”
Howland and his colleagues’ formula relies on a special kind of physics that allows them to estimate the amount of power produced by each turbine based on wind speed and direction and the angle the rotor blades face. His method helps to find the ideal orientation of the blades, without requiring any new hardware or changes to the location of the steel towers.
Modern turbines are designed to detect wind speed and direction, enabling their nacelles – the top part of the turbine that connects the blades to the tower – to be rotated around the tower to better capture the wind. makes. Usually, their software gets them as close to the air as possible.
The scientists say their algorithm shows that more energy is produced by wind farms when some turbines are pointed at closer to a 20-degree angle than when they were operating independently. Will be efficient That change in angle means less impact on the turbines, increasing their overall energy output. Reducing wake turbulence in a wind farm improves collective performance, as scientists’ algorithms allow wind farms to drive turbulent wakefulness through the warrens of turbines in the most efficient way possible.
Over several months of testing their ideas at a wind farm in India, the scientists said, their model increased power output by up to 32 percent under optimal wind conditions.
“The computer model was able to accurately predict the actual wind farm power gain, which we studied as a result of the collective control approach we applied to the farm,” Howland said.
But his team found that there were times when collective control was of no use. On some days, when the winds were too strong or in the wrong direction, they let the turbines operate freely. During several months of testing their algorithms in India, the scientists found that the total energy output from the turbines they studied increased by an average of about 1.2 percent.
Charles Menevue, professor of mechanical engineering at Johns Hopkins, said, “We’re not talking about a huge increase in power for any single turbine, but when multiplied by multiple turbines in a wind farm and multiple farms, It could be very important.” University in Baltimore, which was not involved in the research but studies the physics of air flow.
He added: “I definitely think the industry should implement such containment strategies to experiment with them and see what works.”
Julie Lundquist, an associate professor of atmospheric and ocean sciences at the University of Colorado at Boulder who was not involved in the study, said one potential concern about such “wake steering” of wind through a wind farm is that it can reduce stress. could lengthen turbines – each of which costs millions of dollars to manufacture – and potentially shorten their service life.
“The consideration of the load on the turbine structures is important,” she said.
The paper’s authors called for additional studies that would take a closer look at the impact of their algorithms on turbines, but said their research shows “no risk of catastrophic failures.”
“Long-term, cyclical failures can happen,” Howland said. “We need better studies to model the load.”
However, Howland said the benefits of this method seem to outweigh the potential downsides.
Among those benefits: Their algorithm could allow developers to build smaller, more densely arranged wind farms, using less land or sea level, to produce more electricity, he said. Building fewer turbines would save developers millions of dollars on land and equipment, while smaller footprints could make obtaining permits easier.
Howland estimated that a 1.2 percent increase in electricity produced by the world’s wind farms would equate to the installation of 3,600 new turbines, amounting to about $950 million in additional revenue per year for the industry.
The benefits of offshore wind could be even greater, Howland said, noting that the effect of wake turbulence for downstream turbines may be greater at sea than on land.
“That’s why we need to develop these approaches and adopt them as soon as possible,” he said.
Executives at Vineyard Wind and Mayflower Wind, which both plan to build wind farms in the waters of southern New England in the coming years, said they are interested in learning more about the research.
,[Our] The technical team is reviewing the data and will consider it when looking at construction options when they are determined,” said Daniel Hubbard, general counsel for Mayflower Wind, which built 800 to 127,000 south of Martha’s Vineyard. Federal water leased over acres.-MW wind farm.
Ben Hollisey, an aerospace engineer in the US Department of Energy’s Office of Wind Energy Technology, said similar modeling by the federal government “is showing incredible results.”
“Any technology that can increase energy production in a cost-efficient way can mean more clean energy production, and more money for plant operators,” he said.
Howland urged wind developers to review MIT research and consider adopting the team’s suggestions before building new wind farms.
“It’s critically important that we do it now, as we start building up a lot more offshore wind,” he said. “We need to ensure that our future wind farms maximize efficiency to accelerate the pace of decarbonization.”
David Abel can be contacted at follow him on twitter ,
