The VTT Technical Research Centre of Finland is looking for industry partners to test two anti-blade-erosion coatings for wind turbines that were developed using artificial intelligence.
The research body said blade erosion, which happens when rain, hail, dust and other particles eat away at the leading edge of turbine blades, is costing the wind industry a sum equal to between 2 percent and 4 percent of the value of all wind-generated power production.
A 2014 study, found that blade erosion could significantly impair the performance of wind turbines within as little as five years following installation, and could lead to the need for on-the-ground repairs costing at least $75,000 per set of blades.
“It is a problem that costs billions and brings additional costs to all wind energy,” said VTT principal scientist Anssi Laukkanen, in a statement.
The problem is expected to worsen with increasing turbine sizes and the development of offshore wind farms, he said. On bigger turbines, the blade tips hit speeds that can top 100 meters per second (around 225 miles per hour), Laukkanen told GTM.
And when those turbines are part of offshore installations, they are exposed to more aggressive environmental weathering. Similarly, turbines exposed to desert sandstorms and other particulate-heavy environments would likely incur significant levels of blade erosion.
Where artificial intelligence comes in
To deal with the problem, researchers have looked to develop new coatings that are more resistant to environmental conditions than the formulations used on blades today.
But the quest for such materials has been hampered by the large range of possible candidates and the cost of putting each one through field trials, said Laukkanen. That’s where artificial intelligence comes in.
“Before we start testing something at full scale, we can run hundreds of thousands of computational trials with different material candidates in different environments,” said Laukkanen.
VTT’s "AntiAge" project kicked off last year and has yielded two promising candidates, both of which have already undergone testing within VTT. One is fairly close to present-day materials, Laukkanen said.
This means it could be mass-produced and incorporated into blade manufacturing supply chains relatively easily.
The other is what Laukkanen described as a global optimum, the ideal candidate from an erosion-mitigation standpoint but one that might be more complex and costlier to manufacture. “It’s a completely new material,” he said.
VTT believes either of these options could more or less eliminate blade erosion in the current generation of wind turbines, although Laukkanen pointed out that larger machines with higher blade-tip speeds might require new material formulations.
Looking for commercial partners
For now, state-owned VTT is looking for commercial partners to put the materials through industry trials and help with commercialization. Laukkanen said VTT is in discussions with “the big players in the field.”
The reaction so far has been “more enthusiastic than we expected,” he said. “Apparently...they are quite open to new ideas from research organizations.”
Narciso Lozano, blade engineer at the turbine repair specialist Altitec, said developers are keen to see original equipment manufacturers investing in ways to cut erosion. Blade erosion is a big problem, he said.
“It starts small and it eats its way through the coating of the blade, going deeper and deeper,” he said. “It disturbs the air flow around the blade and reduces the efficiency of energy transformation.”
If neglected, erosion can reduce the lifespan not only of rotor blades but also of main bearings and gearboxes. Dealing with erosion is an inherent part of rotor blade operations and maintenance, he said.
The current best practice for dealing with the problem is to apply leading-edge protection in the form of add-ons that may or may not be specific to the blade model. These retrofitted leading-edge protection solutions include liquid coating, tape and soft shells, Lozano said.
“Manufacturers increasingly understand the need to enhance rotor blade leading-edge protection due to the significant efficiency issues that can result from erosion,” he said.
“The complexity of blade damage repair depends on the stage of erosion, the worst of which can require a lot of experience and extensive investment in time and materials."