02/25/2018

Does offshore wind farms steal the wind from each other?

Large wind farms will also play an important role in Denmark's green change in the future. However, one has to think strategically when a wind turbine is positioned so the wind farms do not cause problems for each other. A new project by DTU Wind Energy in collaboration with Vattenfall will look at that problem.

Today, there are 13 wind farms in Denmark and several are expected in the future. Although it sounds positive with several wind farms, clusters with many wind farms close together can have certain disadvantages. DTU Wind Energy and Vattenfall have therefore joined forces in working on the project 'OffshoreWake'. The project investigates how offshore wind farms should be positioned so that they do not steal the wind for each other.

Project Manager from DTU Wind Energy, Xiaoli Guo Larsén explains about the project: "If you do not think strategically about the location of the major wind farms in the future, then they could cause a reduction in electricity production from other wind farms located nearby," she says.

When wind farms are in the way of each other

The reason is the so-called shadow effect. When a wind turbine is hit by the wind and exploits wind energy to produce electricity, there will be less wind behind the wind turbine. The "rearward" wind turbines will, therefore, produce less energy. The same can be the case with the wind farms themselves.

"The calculation methods that are used today take the shadow effect inside a wind farm into account. But DTU Wind Energy and Vattenfall will expand the calculation method with two additional components, "adds Xiaoli Guo Larsén.

The two new components are the shadow effect from nearby wind farms and ocean surface parameters such as waves. Both are important to include in the calculations if we are to get the most out of new wind farms in the future, Xiaoli Guo Larsén says.

The project, which will be completed in April 2020, will also investigate how the shadow action between the major parks will affect the planning and operation of the electricity system.

About the reason for joining the project, Vattenfall says: "We are constantly working to develop more precise methods for estimating production from offshore wind farms. The 'OffshoreWake' project should make us even better at predicting how much two wind farms affect one another. This will reduce uncertainty and make it easier to make investment decisions, "says Ylva Odemark, Research Director of Wind Power in Vattenfall.