How to Prevent Ice Buildup on Wind Turbines in Winter

Wind turbines are popular options for helping the world reduce its need for fossil fuels and anticipate a greener future. However, engineers, designers and others who work directly with this renewable energy equipment realize they must research practical options for preventing the buildup of ice on the blades.

When those components freeze, they can negatively impact the turbine’s aerodynamics, making it less efficient. The ice is enough to stop the equipment from functioning in severe cases. Such consequences hurt a power company’s return on investment and can cause electricity outages.

For example, when Texas had a period of bitterly cold weather in early 2021, the frozen conditions caused a 16-gigawatt loss of renewable energy sources, including wind. Additionally, the wintery temperatures took 30 more gigawatts offline produced by coal, nuclear and gas.

Some renewable energy critics quickly concluded that wind turbines fell short of their potential since many froze during that time. However, as other people pointed out, wind power was not the only power source to struggle with the cold.

Study Examines Where Ice Buildup Occurs

It’s not easy to determine the best way to handle icy turbine blades before getting more details about the scope of the problem. That’s why researchers at Iowa State University conducted a field study to learn more about ice buildup and gauge the extent of the problem.

One of the takeaways was that the ice could accumulate to nearly a foot thick on turbine blade tips. Additionally, such buildups can cause a drop in energy production of up to 80%. The researchers got that data after using drones to take pictures of 50-meter turbine blades after up to 30 hours of exposure to winter weather.

They discovered that while the ice can appear anywhere on turbine blades, it’s typically most severe on the outboard ones. Moreover, the team confirmed that such buildup causes significant performance decreases, even in high-wind conditions.

These findings emphasize the importance of creating a detailed strategy to cope with ice buildup. Here are some of the angles you could try.

Use Ice Detectors and Monitors

One proactive option is to install ice sensors on the turbines. The most modern products on the market detect ice films only molecules thick, and they’re about the size of a thumb. These products span from basic to advanced. Some only verify the presence of ice and provide notifications of that issue. Others link to systems that circulate hot air near the turbine, serving to monitor for ice as well as melt it.

Once relevant parties, such as wind farm managers, are alerted about ice buildup, they could use other technologies to further investigate the matter. One method is to use drones to survey the area and get a closer look at the extent of freezing on the blades.

Besides the products already on the market, researchers engage in ongoing work to bring further improvements to ice-sensing technologies. In one example, a team built microwave sensors that detect the level of buildup and the melting rate.

Other technologies in this space rely on lasers and acoustic sensing. As wind power increases in prominence, you can expect even more possibilities to become available soon. In any case, the wide assortment of sensors on the market now allows plenty of opportunities to start your research.

Apply Anti-Frost or Icephobic Coating

Icephobic coatings could also help wind turbines maintain the desired performance in cold weather. Some of these products contain volatile organic compounds (VOCs), meaning people must take extra care to avoid contributing to air pollution. However, it’s increasingly easy to verify whether a product contains VOCs. In California, products containing any one of more than 800 chemicals must have specific labels to designate such ingredients.

Many manufacturers make low-VOC coatings that minimize the associated health and air quality risks. Researchers also created a VOC-free method for using icephobic coating on wind turbines. They developed a single-step flame-spraying process for the layer’s production. The team reported that this approach did not require post-curing or working in a controlled environment.

Icephobic coating is a passive method that can substantially limit how well ice adheres to the treated surface. It also does not require a heat or energy source to work. Similar to how there’s ongoing work to make better ice sensors, scientists want to improve existing icephobic coatings.

An innovation from the University of Illinois could pave the way for next-generation coating solutions. The researchers believe phase-switching liquids (PSLs) have properties that could make them ideal for slowing frost formation on surfaces. They said PSLs might hold off ice and frost accumulation 300 times longer than products currently under development.

Deploy Surface-Melting Methods

Wind power is widely used in particular parts of the United States. For example, South Dakota generates one-quarter of its total power that way, and Texas produces more than 20% of the wind power in the country. However, the Lone Star State recently attracted wind turbine-related attention for another reason, although a misappropriated and outdated one.

In addition to applying coatings for de-icing wind turbines, it’s sometimes necessary to spray water or chemicals to melt ice after it accumulates. Texas was in the spotlight recently for a photo that went viral on social media that supposedly showed a helicopter removing ice from a turbine by applying chemicals to it.

People claimed the environmentally friendly aspects of the wind turbine were overshadowed by the effects of using a helicopter that runs on fossil fuels and using a de-icing agent. However, fact-checkers verified that the picture came from Sweden and is several years old. Plus, in this case, the helicopter sprayed hot water, not chemicals.

One study examined using a helicopter to apply hot water to affected parts of a turbine to gather more details about the effectiveness of this method. The researchers found that it worked well in temperatures as low as 20 C. Additionally, this technique allowed for the full de-icing of a turbine in about 90 minutes.

De-Icing Wind Turbines Requires Proactive Methods

Ice buildup is a near certainty if you plan to use or build wind turbines subjected to cold climates. However, you now have several ways to combat it. Besides choosing the most appropriate option for your circumstances, realize that fast action is another crucial aspect of controlling the issue.