A mathematical tool developed at the Danish Technical University and windfarm developer Vattenfall is enabling the company to optimise power generation and reduce costs on offshore windfarms.
Designing offshore windfarms involves highly complex optimisation challenges. When a windfarm is designed, numerous factors must be taken into consideration such as wind direction, water depths, erosion zones, foundation costs, physical obstacles, types of cables, cable loss and that the wind turbines do not cast ‘shadows’ on each other. The location of each individual turbine in a windfarm is extremely important to ensure they do not ‘steal’ energy from the turbines behind them.
The windfarm design process used to be cumbersome and could take weeks, but a new approach developed by project lead engineer and PhD Martina Fischetti has changed the design process. She recently received Innovation Fund Denmark’s 2019 Industrial Researcher prize and the project is among the finalists in the 2019 INFORMS Franz Edelman Award for Operational Research and Analytics.
Windfarm design used to be a multi-step process depending heavily on the experience of the individual engineer and standard tools. A preliminary layout was generated and checked. If the layout wasn´t acceptable, turbine locations were manually adapted, the layout passed to another team for checking and so on. The overall process was time consuming and the results were suboptimal.
“The new tool streamlines the process so that all of the factors are considered in the software at the same time. The program performs thousands of simulations considering all of the relevant factors before it delivers an optimised layout for the location of the turbines and cable routing,” Dr Fischetti explains.
“By optimising turbine layout and cable routing we can reduce costs and increase production. Our new approach can achieve gains of €10M for each farm. In this way we can reduce the cost of wind power”.
The software was used to design the Kriegers Flak offshore windfarm in the Danish sector of the Baltic, which was awarded to developer Vattenfall with a record-low bid. It was also used for Hollandse Kust Zuid 1 and 2 offshore windfarms in the Netherlands, the first project in the world that will be built without any subsidies.
Vattenfall head of system design, business unit offshore wind Thomas Hjort says, “I had never seen these techniques used on this type of problem before, and the results achieved are remarkable and outperform the traditional systems every time.
“What is also extremely exciting is the momentum the tool has given to the team, allowing us time to experiment and think outside the box. We can test the new ideas and alternative solutions straight away and quantify the impact of new design choices from the outset. We can also engage with suppliers in a novel way and drive innovation in a long term.”
All in all, said Vattenfall, the novel layout optimisation tool has contributed to the company’s competitiveness in tenders, helping to create better layouts, quantify the impact of design choices and deliver input for alternative business cases for each windfarm. The company anticipates that the tool will become important as Vattenfall expands in the wind sector.
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