Wind Blade Manufacturing: Hand Layup to ABB Robots

A modern wind turbine blade can be longer than a football pitch, and most of it is still built by hand. Workers lay glass fibre into huge moulds, fill it with resin, then grind, sand and paint the finished shell. This post follows wind blade manufacturing from the steel blades of the 1940s and the first fibreglass blades in Denmark, through resin infusion, to October 2026, when Suzlon announced three new blade factories with robots and AI inspection. It also looks at where ABB robots can take over the dusty finishing work, and what makes blades hard to automate.

Finished wind turbine blades stacked in the mist at Hull, England. Photo: Paul Harrop / Wikimedia Commons (CC BY-SA 2.0)

How the first turbine blades were built by hand

The first megawatt turbine had metal blades. In 1941 the Smith-Putnam machine on Grandpa's Knob in Vermont started feeding power into the local grid. It was rated at 1.25 MW and turned two stainless steel blades on a lattice tower. In 1945 one of them broke off, and the project was not rebuilt. Heavy metal blades set a limit on how big a rotor could get, and for decades very few large turbines were built.

The Smith-Putnam wind turbine on Grandpa's Knob, Vermont, around 1941. Photo: US Department of Energy via Wikimedia Commons (public domain)

Denmark kept going on a smaller scale. Johannes Juul's Gedser turbine of 1957 had three blades braced with steel stays, and it ran for about a decade. Its layout of three blades facing the wind became the Danish model. In 1978 volunteers and students at the Tvind schools in western Jutland finished Tvindkraft, a 2 MW turbine with fibreglass blades they built on site. Photos from the build show a long white blade going up on crane wires while a group of people watch from the ground.

The rotor of the 1957 Gedser turbine, with its three blades braced by steel stays, on display in Denmark. Photo: Villy Fink Isaksen / Wikimedia Commons (CC BY-SA 3.0)

Fibreglass blades soon became an industry. LM Glasfiber started in 1940 as a furniture factory in Lunderskov, Denmark, moved into glass fibre in 1952 and began making wind turbine blades in 1978. The early method was hand layup: workers laid dry glass mats into an open half-mould, wetted them with resin using brushes and rollers, and then glued the two half-shells together. The work was slow and messy, and the open resin gave off fumes. Every blade came out slightly different, depending on the crew that made it.

A fibreglass blade is lifted during the building of the Tvind turbine in Denmark, 1978. Photo: Jevanadezda / Wikimedia Commons (CC BY-SA 4.0)

Inside blade factories in 2026

Blade makers moved to closed processes. In resin infusion the dry fibre is laid in the mould, covered with a vacuum bag and the resin is pulled through it. Infusion became the standard once blades passed about 60 m, and Siemens, now Siemens Gamesa, casts its IntegralBlade in one piece in a closed mould, with no glue joint. Laying the fibre, placing the balsa or foam cores and finishing the surface are still mostly manual, and factories like Siemens Gamesa's plant in Hull store rows of finished blades outside.

Workers finish a giant blade at the LM Wind Power factory in Grand Forks, North Dakota. Photo: Tuey / Wikimedia Commons (CC BY 2.0)

On 24 September 2026 CRRC said it had finished a 110 m recyclable blade in Sheyang, Jiangsu, made with a debondable infusion resin that lets more than 95% of the key materials be recovered. On 11 October Suzlon said it would spend about Rs 550 crore on three blade factories in Gujarat, Karnataka and Tamil Nadu by 2027, using robotics, automation and AI vision systems that spot manufacturing defects. The new plants will sit closer to wind farm sites to cut transport costs, and Suzlon expects about 3,000 direct jobs. It already runs five blade plants, in Jaisalmer, Bhuj, Ratlam, Dhule and Anantapur.

Turbine blades stored outside the Siemens Gamesa blade factory in Hull, 2023. Photo: Paul Harrop / Wikimedia Commons (CC BY-SA 2.0)

ABB has worked on blade finishing before. In 2010 it presented a robot coating concept for rotor blades, with two IRB 5400 paint robots on rails beside a fixed blade, or a mobile paint booth that travels along blades of 80 m and more. ABB said it cut paint shop energy by up to 60% and paint use by 25%, and the fixed version had painted blades up to 50 m long in Europe. Today ABB's IRB 5500 paint robots do this kind of work on car bodies, and arms like the IRB 6700 with force control grind steel parts in cells such as Teqram's EasyGrinder.

ABB paint robots working on a car body inside a paint booth. Photo: ABB

What blade factories need from robots next

Grinding and sanding are the obvious next jobs. After a blade comes out of the mould, workers in masks and suits grind the bond lines, sand the whole surface and fill small defects, a dusty job on a part tens of metres long. Robots on rails or mobile platforms can do this with steady contact force, and a large ABB arm such as the IRB 6700 could carry the grinder. For blades already in service, our post on wind turbine blade repair covers the robots that work on the tower.

An ABB IRB 6700 grinding a steel part in Teqram's EasyGrinder cell at Ancofer. Photo: ABB

Size is what makes blades awkward for robots. A robot cell for a 110 m blade needs long tracks or moving gantries, and the blade itself bends and sits in a slightly different place every time, so the robot has to measure it before it works. Paths for such big parts are usually planned and checked in RobotStudio first. Blade designs also change every few years, so plant owners are wary of fixed automation. Tower makers face a similar problem, as our post on wind tower welding describes.

A blade is loaded onto the transport ship Blade Runner Two at the Vestas blade factory on the Isle of Wight. Photo: ITookSomePhotos / Wikimedia Commons (CC BY-SA 4.0)

Recycling adds another step. CRRC quotes industry estimates that more than 30,000 turbines will have been retired in China by 2030. Blades made with debondable resins, like CRRC's, will need to be cut and taken apart at the end of their life, which is heavy, repetitive work suited to large robots. Cost is the main brake, since many blade plants are in places where labour is cheaper than a long robot cell. Plants like Suzlon's new ones will also need technicians who can program and maintain robots and vision systems, and those skills are scarce near rural wind sites.

An ABB IRB 6700 lifts a solar module for a folding roof at dhp technology. Photo: ABB

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