Today, wind power is the energy source with the greatest potential in the transition towards green energy in Sweden. A national political goal dictates that all electricity production should come from 100 percent renewables by 2040. From today's 11 percent, wind power is estimated to make up at least 40 percent of the Swedish electricity production within a couple of decades, probably more. The Swedish Wind Power Technology Centre (SWPTC) unites theory and practice in a close collaboration between industry and academia. The common goal is to optimise the capacity of wind turbines and make production and operation more cost-effective.
New methods for lowering costs and prolonging life-span
Unforeseen down-time in production can incur high costs for wind power owners, not only because of faulty components that need replacing, but also because of reduced revenue due to no energy production.
“In the transition towards 100 percent renewable energy in Sweden, it is important that we can take care of our wind turbines, as they will count for a large part of the electricity supply in the future. An important contribution from SWPTC in promoting the wind energy expansion is to develop better maintenance methods and knowledge about prolonging the life-time of wind turbines”, says Sara Fogelström, who is the coordinator of the research centre.
With data from the wind turbine, one can calculate the expected life-span of different components and, on that basis, provide an optimal maintenance schedule. It also means that you can schedule the maintenance to a time when there is little wind, when the wind turbine would have a low production anyway.
“The methods developed within SWPTC advocate a so-called opportunistic maintenance, which means that the system proposes replacing of several components at once, as the service technician is on site. Problems can then be addressed before they become too costly and, also, you do not have to go out to the windfarm as often, Sara adds.
Several research disciplines in collaboration
Until now, the centre has been building up fundamental knowledge, through individual research projects, within each of the research disciplines needed to understand how a wind turbine works. For example, at Chalmers, researchers in fluid dynamics are looking at how wind turbines in the forests are affected by the surrounding terrain. Researchers in dynamics investigate how the mechanical drive train, and in particular the gearbox, works. In electric power engineering, research is being carried out on detection of electric faults in the generator and how windfarms can be better connected at sea. Furthermore, researchers in construction engineering are interested in how different loads (“forces”) affect the foundation of the wind power turbine. Mathematicians are also involved in calculating how to optimise the maintenance methods.
One of the projects that endorses the entire spectrum of competences is a project about how individual wind turbines are affected under harsh operating conditions. In complex terrain, it is subjected to ever-changing winds, which results in greater mechanical stress on the gearbox than it would in flat terrain. This explains why maintenance costs are often much higher in Sweden, which has a hillier terrain, than Denmark, which is mostly flat.
With a new calculation model, researchers can see exactly how the wind field of each individual wind turbine behaves in a wind farm. The image is a cfd simulation (Computational Fluid Dynamics simulation) created by Hamidreza Abedi, Chalmers.
The loads that each individual wind turbine is subjected to can vary a lot within one single wind farm.
Ola Carlson is a Professor at the Division of Electrical Power Engineering and the Director of SWPTC. He is leading the project, which is carried out in collaboration with several industrial partners.
“We have developed a calculation model that takes many different parameters into account, which can calculate the accumulated load that an individual wind turbine is subjected to. This knowledge is needed for manufacturers to be able to adapt the design of wind turbines to different operating conditions”, says Ola.
An international player
The research results have received attention also outside Sweden. The centre is now participating in several international networks and organisations, such as the European Energy Research Alliance, the European Academy of Wind Energy and the international energy agency IEA.
“It is an important strategic move. We have already received inquiries of collaboration in major EU projects. Besides being a collaborative platform, it is also a way of spotting trends in the field”, Sara concludes.
About Swedish Wind Power Technology Center (SWPTC)
The centre was established in 2010 and during the first two stages, 35 research projects were carried out in collaboration with 26 industrial partners and research institutes. Prior to the start of stage 3 in January 2019, the research had generated 38 published articles and eight doctoral theses. The research is financed by the Swedish Energy Agency, Region Västra Götaland (VGR), as well as the participating companies and academic parties.
Read more on SWPTC's homepage www.swptc.se
Sara Fogelström, coordinator of SWPTC, firstname.lastname@example.org
Ola Carlson, Director of SWPTC, email@example.com
Text: Anna Wallin
Portrait photos: Oscar Mattsson