Winds of opportunity

Share This Post
The future of wind power turbines is big, complicated, and lucrative. Is your shop up to the challenge? PHOTO by Pexels

Is there a windfall to be made from the expected growth of wind power turbines for shops capable of handling the complexities of machining and fabricating increasingly larger components?

Globally, we are in the midst of a surge in wind power capacity. According to the International Energy Agency (IEA), wind power capacity is forecasted to grow by more than 50% from 2021 to 2026, driven by declining costs and technological advancements that are making wind power increasingly competitive with other energy sources. If the business opportunities from wind power aren’t on your radar screen as a “hot market” that’s likely because North America has so far been a laggard in wind power adoption. As of the latest-available records, wind energy capacity in North America stands at 155 GW, compared to 255 GW for Europe and 650 GW for Asia. Nevertheless, considering a net zero carbon electric sector in North America is estimated to require a bit over 2,000 GW of installed wind and solar capacity, it’s clear there is considerable room for growth. IEA believes wind power could be providing close to a fifth of global electricity by 2050.

A typical large utility-scale wind turbine consists of about 8,0000 parts and it’s estimated that up to 70% of these parts are made from metal. Steel is a fundamental material in wind turbine construction due to its strength, durability, and suitability for various structural and mechanical parts. The tower structure can constitute a significant percentage of the total steel content in the turbine, typically ranging from 60% to 80% of the tower’s weight. Steel is also prevalent in the nacelle and drivetrain components such as the main shaft, gearbox housing, bearings, frame structures, and other mechanical parts. This portion of the turbine can account for around 30% to 40% of the total steel content.

While wind turbines contain no shortage of parts for metal working shops, what will prove challenging is the trend towards turbines getting larger in every dimension, with taller towers and larger rotors, and also being situated in more challenging environments. Over the next couple of years, a new generation of wind turbines are expected to increase in size by an average of 60%, growing in total height to 202 meters from the 122 meter models deployed during 2011-2020, according to the US Wind Energy Technologies Office. Wind turbines are getting larger to become more efficient. Larger turbines can capture more wind energy and generate more electricity per unit of land area. GE Renewable Energy’s Haliade X turbine has a rotor diameter of 220 meters while Siemens Gamesa’s SG 14-222 DD turbine has a rotor diameter of 222 meters. Both have the potential to generate enough electricity to power thousands of homes in just one rotation.

Although more energy efficient, the trend towards much larger wind turbines presents distinct challenges for machine and tool manufacturers. Even today in order to work on a forged main shaft measuring four to five metres and weighing more than 20 tonnes, some six to eight tonnes must be sliced away. There is also the material handling part of the challenge for the machine builders, putting the part on and off the machine, locating it, and getting it properly lined up. 

“We’ve all seen these huge wind turbines,” acknowledges Tracy Rhodes, strategic relations account manager with Sandvik Coromant. “Typically, what we are working on is the planetary gears and gearboxes for them and it creates a challenge for off the shelf tooling. For one thing, the tools have to be so much larger. It’s required to provide reach capability. Larger tooling, bigger inserts, higher wear resistance — all those things are going to play into addressing the parts getting bigger and bigger.” 

The construction of wind turbines also presents issues for tooling. 

“If you look at wind power and look at the gear box housing, it’s a very big hollow box that looks like it’s made of several rings. It’s really thin walled in a lot of places and that can create a lot of harmonics and that definitely works against us,” says Rhodes.

To deal effectively with the move towards larger wind turbine components shops must consider both machines and tools specifically designed for such applications, Rhodes advises. He points to the evolution of Sandvik Coromant’s Silent Tools technology, which started with boring bars and migrated into adapters for milling tools and then the actual milling tool with the dampening mechanism built in.

“These parts getting larger and larger led us in that direction because of the really long reaches we had to accomplish. Also, when you get a really big part, a change in insert right in the middle of a cut is not always the easiest thing to do. The tooling is deep in the hole, you can’t see it, how do we know what’s really going on in there other than by sound and feel?” he posits. “A good machinist can hear and feel what’s going on but sometimes that’s not an option when we are talking about machines that could be as big as a small house with a part the size of an SUV stuffed into it. We also have the Silent Tools Plus technology that has sensorized boring bars and sensorized technology within the machine that can really tell you exactly what is going on at the cutting edge when it comes to vibration and heat and surface finish.”

Another wind turbine trend certain to pose challenges is installing wind turbines in offshore locations, installed with either a fixed bottom in shallow waters or on floating platforms in deeper waters, where wind resources are even more abundant and land conflicts minimal. Floating offshore wind in particular has a huge potential to unlock new markets, especially in North America where the seabed is steep and unsuitable for fixed-bottom turbines. Fabricating either of these colossal structures to ensure their structural integrity is a similarly colossal task. Seawater is highly corrosive due to the presence of chlorides and microorganisms and dried-off seawater can leave chlorides on the surface of metals like stainless steel, leading to protective film breakdown and pitting corrosion that can spread unpredictably.

“These massive structures rely on welding technologies to produce safe joints in conditions where one bad weld can cause devastating consequences,” states Red-D-Arc, the largest provider of welding rental products and services in North America in its report The Critical Role of Welding in Offshore Platform Construction. It explains that wind turbine towers are welded from many large diameter cans with thick metal plates rolled into cans using specialized equipment. Once rolled and tack welded, seam welding equipment is used to produce a longitudinal weld, essentially forming a single can.

Due to the sheer size and weight of the individual cans, they must be rotated and fit up using advanced growing line fit-up systems. The fit-up bed station rotates and translates the tubular sections, aligning them correctly for an appropriate joint fit-up. Next, automated welding manipulators apply the submerged arc welding (SAW) welding process to join the tubes, Red-D-Arc explains.

Arc stability is critical but not easy to achieve under such conditions with conventional power source technology due to the high puddle dynamics created by high deposition rates and multiple arcs in the same weld pool.

“Such massive tubular pieces need powerful, and above all, reliable SAW welding power sources.” Red-D-Arc asserts.

So, circling back to the question asked at the outset: Can the expected growth in wind turbines present a windfall for Canadian job shops? The answer would seem to be yes, provided they’re already versed in handling large parts and willing to deal effectively with the challenges mentioned.

As Sandvik Coromant’s Rhodes point out, with such jobs you have to get it right the first time. Preventive maintenance is a bit more difficult when the wind turbine platform is out at sea and you have to take a helicopter to get there. SMT

Share This Post

Recent Articles

Wordpress Social Share Plugin powered by Ultimatelysocial

Enjoy this post? Share with your network