Turbine test site enables research on wind farm management
The new model wind farm at Wieringermeer in the Netherlands will allow ECN to carry out pioneering wind research in order to find answers to questions such as how wind turbines in large wind parks interact with one another. The opening of the wind farm was celebrated in early September.
Photo: P. Eecen, ECN.
The model farm, constructed at the existing ECN test site in Wieringermeer, has ten wind turbines, ten small monitoring masts and four large monitoring masts. The wind turbines have a rotor diameter of 7.6 meters, a tip height of 11.3 meters and a capacity of 10 kW. The model farm may therefore not be as impressive as the powerful wind turbines which make up the skyline of the Wieringermeer area since 2003, but, said Dutch weather forecaster Erwin Kroll in his opening speech; the research results from the model site are certainly expected to be. “This model farm is the pièce de résistance as far as research into maximum wind turbine output is concerned. When objects stand close together, it influences the air flow. This must be investigated in order to be able to place wind turbines as efficiently as possible.”
Air flow
This research can be carried out at the model farm. A unique feature of this test site is that the turbines at the ‘front’ pass on information to the other turbines, which can then adjust the angle of their rotor blades and rotational speed accordingly. ECN Wind Energy unit manager Theo de Lange: “This model farm enables ECN to strengthen its position amongst the world’s best in wind energy research. By mapping the air flows we can develop and test control strategies in order to increase wind farm electricity production. It is therefore an essential addition to the computational research which has been carried out by the unit for many years. The reduced wind velocity and altered wind structure (wake) behind a wind turbine cannot be calculated accurately using the current models, and wind tunnel research is not providing any answers either.”
Cultural heritage
Despite the rain, the opening on September 5th was celebrated in style. Guests in the storm-proof tent listened with interest to weatherman Erwin Kroll’s speech, who was the host for the occasion. “The wind blows and the windmills turn. This has been a way of life for a long time in the Netherlands. Look at these turbines and see how beautiful they are. There were also many objections in the past to our now traditional windmills. They were thought to be noisy and to spoil the view. But the Netherlands owes its existence for a large part to these windmills. Windmills sawed the wood which was used to make our trade ships, and windmills pumped the reclaimed land dry. Now they are a part of our cultural heritage and everyone agrees that they are beautiful. This will also be the way with these turbines: they are the cultural heritage of the future!”
Mayor Leegwater of Wieringermeer and Deputy Heller of the Province of Noord-Holland, switched on the model turbines in a light-hearted way: for every right answer to a ‘wind quiz’ a ship’s horn blasted over the model farm and another of the model turbines obeyed by starting to turn. In reply to the question when the license for extension to the test site would be ready, Leegwater reported that it was being worked on. “I won’t deny the existence of a little ‘wind fatigue’ in the council”, said Leegwater. “There is some doubt. The executive councillors now need to convince the city council, and if they manage to do so I am sure that the discussion can be brought to a close before the end of the year. The license will then soon follow.”
History
Wim Stam, managing director of ECN Wind Energy Facilities BV, looked back at the creation and realisation of the plans for a model wind farm. “The idea to create a model farm was born two years ago. The choice of location here at the Wieringermeer was logical. With nine existing large turbines here, the infrastructure was already in place, as was the monitoring pavilion which receives data from the large turbines. It was a simple task to add the data from the small turbines.
Applying for the licenses cost a lot of time. The model farm lies between two large wind turbines (each of 2.5 MW) on a piece of ground designated for wind energy in the land-use plan. Nevertheless, an exemption procedure was required, because the plan applied to turbines with an axis height of over 40 meters. The model farm turbines are just 7.6 metres high. All in all, it was a lot of work, similar to that required to set up a large wind farm. But now ECN Wind Energy can get started.”
Kai-Uwe Broek, managing director of the German firm Aircon, manufacturer of the small turbines stated: “These turbines were specially constructed for ECN. We are specialised in the construction of small wind turbines, but had never made any of this type before. We were therefore very interested in the design of the wind farm. The turbines in this farm are in exact proportion to the large wind turbines, necessary to ensure that the data is as accurate as possible. We also constructed rotors with blade angle control especially for ECN. This intensive collaboration has been of benefit to both ECN and Aircon: they have the benefit of our expertise and we have the benefit of access to the research results.”
Information:
More information on the wind turbine test site at the Wieringermeer, is available on the internet of ECN.
Contact:
Peter Eecen / Wim Stam
ECN Wind Energy Facilities BV
Tel.: (+31) 224 - 568279 / 4025
eecen@remove-this-part-ecn.nl / stam@remove-this-part-ecn.nl
