Offshore Wind Farms Just Need a Little Stagger to Generate More Power

A new approach to spacing offshore wind turbines could significantly increase capacity

2 min read
Offshore Wind Farms Just Need a Little Stagger to Generate More Power
Photo: Mariusz Paździora/Wikipedia

Neat rows of wind turbines dot seas and oceans across the world. But setting offshore wind turbines in straight lines may limit their power production, according to a new study.

Whether wind farms are on or off shore, there is a tradeoff between getting maximum energy from each individual turbine and packing a greater number of turbines into the space. As each turbine pulls energy from the wind, there is less energy in the downstream wind, which causes array losses for the entire wind farm. (Turbines not only affect their immediate neighbors, they can also affect other arrays miles away.) 

But there may be a simple solution to boost energy production without expanding the boundaries of offshore wind farms. Researchers at the University of Delaware found that staggering turbines in the ocean can improve annual power capacity by 13 to 33 percent. The study appeared in the September issue of Geophysical Research Letters.

“Staggering every other row was amazingly efficient,” Cristina Archer, associate professor of physical ocean science and engineering and geography in University of Delaware's College of Earth, Ocean, and Environment, said in a statement.

The study used the Lillgrund wind farm near Sweden, which has turbines packed into straight rows, as its model facility. The researches then simulated six alternative configurations. Each of the simulations took weeks to run and accounted for the downwind eddies that turbine blades produce as they spin as well as the prevalent wind directions.

Some of the simulations looked at simply spacing the turbines further apart in rows, while others staggered the rows. Staggering every second row was the simplest method to improve capacity factor. The simulation showed that staggered turbines reduced array losses from 36 to 27 percent.

The most efficient combination was a both more spacing and a staggered layout, which dropped array losses to 14 percent and doubled the capacity factor for the wind farm.

Other researchers have developed complex algorithms to optimize wind farm patterns to maximize output and have also found that larger spacing can increase power production. But staggering could be a solution that allows for increased capacity without greatly expanding the footprint of wind farms. 

The spacing of turbines, both in a single array and regional arrays, is just one consideration. Archer has also studied the seasonal variability of wind farms and how dominant winds can change throughout the year.

Despite the many factors that can reduce overall energy output, Archer’s previous research has shown that today’s wind turbines could supply energy for about half the world’s power needs.

The Conversation (0)
This photograph shows a car with the words “We Drive Solar” on the door, connected to a charging station. A windmill can be seen in the background.

The Dutch city of Utrecht is embracing vehicle-to-grid technology, an example of which is shown here—an EV connected to a bidirectional charger. The historic Rijn en Zon windmill provides a fitting background for this scene.

We Drive Solar

Hundreds of charging stations for electric vehicles dot Utrecht’s urban landscape in the Netherlands like little electric mushrooms. Unlike those you may have grown accustomed to seeing, many of these stations don’t just charge electric cars—they can also send power from vehicle batteries to the local utility grid for use by homes and businesses.

Debates over the feasibility and value of such vehicle-to-grid technology go back decades. Those arguments are not yet settled. But big automakers like Volkswagen, Nissan, and Hyundai have moved to produce the kinds of cars that can use such bidirectional chargers—alongside similar vehicle-to-home technology, whereby your car can power your house, say, during a blackout, as promoted by Ford with its new F-150 Lightning. Given the rapid uptake of electric vehicles, many people are thinking hard about how to make the best use of all that rolling battery power.

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