Bringing Minnesota Wind Turbines Back to Life
By Nidas Kudzin
Aging is a reality we all have to face one day, and this includes wind turbines. The first wind farm in Minnesota was constructed in 1994 on Buffalo Ridge, in the southwest corner of the state. However, the average lifespan of a wind turbine is 20 years, which creates a problem for the Buffalo Ridge wind farm and many other farms across the state. Which raises the question, what do you do when a wind turbine is reaching the end of its life span?
You have heard about decommissioning wind turbines, and possibly the false claims that wind turbine blades are not recyclable. However this is only a portion of the answer to this problem, the complete answer is to repower our old and aging wind turbines. Repowering combines commissioning new wind turbines, and refurbishing old aging turbines or disassembling them to create room on the farm. This allows for retrofitting aging turbines with new technology that is more energy efficient and allows for greater energy production as well. The process also allows for targeting of specific turbines which are performing the worst, as all turbines age differently.
In 2013, a UK study researched the impact of age on the load factor of a wind turbine, it was found over a 19 year lifespan the load factor decreased by 12%. The load factor is a ratio of total energy generated, compared to the total possible energy generated at maximum capacity. This has a major impact on the efficiency of energy generation, which leads to higher cost electricity as a turbine ages. The impact of lower production is then passed onto the consumers in the end. Repowering doesn’t just offer technological benefits for owners and possible cost savings for consumers, there are more benefits hidden in the approval process.
The approval process for a wind farm is long and tedious, with planning to construction taking upwards of 5 years to complete. This makes repowering even more appealing for owners, the shorter turnaround time can start to make an immediate impact sooner. Other issues new wind projects face are expensive land rentals or limited land plots for purchase, which also require a myriad of government surveying. This makes repowering even more appealing as our population continues to grow and large land plots become more and more scarce.
Taking a closer look at home here in Minnesota, Xcel has been leading the way with repowering projects. In 2021, the Minnesota Public Utilities Commision approved Xcel Energy to repower their Grand Meadow wind farm. This wind farm was originally constructed in 2008, with an expected life span of 25 years. This new repowering project would extend the life of the farm to 2048, adding an additional 25 years of production for the farm. The approved plan includes replacing the old blades with new longer blades, and retrofitting the old operating systems with more efficient equipment. Xcel claims that this upgrade could lead to at least a 10% increase in production for the farm of 67 turbines. This is only one of many repowering projects they have completed or are currently planning for as Xcel works towards their goal of 100% renewable energy by 2050.
As we work towards a future of carbon free electricity generation, repowering will be a key factor in the green transition. Repowering is giving aging turbines a second chance at life, where previously decommissioning was the only option. With this new found information, hopefully you can be a better informed participant in deciding our energy future.