DBI: Free courses in H2 and PtX safety

DBI’s role in GreenSkills4H2 project

DBI - The Danish Institute of Fire and Security Technology - is participating in the international project GreenSkills4H2 to contribute with expertise in fire, safety and risk management to the development of training programs for hydrogen technologies. As hydrogen becomes a central part of the green transition, DBI supports the project’s goal of preparing the workforce with the necessary skills to handle hydrogen safely and responsibly.

Danish precision machining specialist CNC Onsite and Dutch blade expert We4Ce have completed their first joint project transferring repair know-how to a wind farm in South Asia. In May, the customer’s technicians were trained to independently repair loose inserts in the root ends of 26 turbine blades. This was the first time the companies' new repair method was put into practice. The method offers a cost-effective and sustainable alternative to full blade replacement by eliminating the need for external transport and potentially reducing blade waste.

CNC Onsite’s specially built precision machine removes the damaged inserts directly on-site, allowing the wind farm’s technicians to apply We4Ce’s patented "Re-FIT" method for mounting and securing new inserts. Prior to the launch of the 50 MW project in South Asia, the technicians were trained in the repair method at We4Ce in the Netherlands and in operation of the precision machine at CNC Onsite in Denmark. The technology is delivered under a licensing model, enabling wind farms to carry out major blade repairs with their own service teams.

Following the training, the customer’s service team in South Asia established a temporary workshop directly in the wind farm, where extensive repairs were carried out over several weeks under the supervision of CNC Onsite and We4Ce.

"Securing and now executing this first contract for our new insert replacement method directly in the wind farm was the result of solid engineering with a focus on practical application," says Arnold Timmer, Managing Director of We4Ce. "We got the idea in early 2022 following a project with a customer in India and then spent three years developing and testing the solution."

By applying the repair technology, the customer will now be able to replace more than 1,000 defective inserts. The process combines precision boring, a specialized fastening method, and installation of replacement inserts, resulting in a component that is nearly as good as new, designed not only for reliable performance but with a projected lifespan of up to 20 years. This process represents a significant improvement over conventional repair methods.

Repair Technology: A Future Opportunity for Operations and Maintenance (O&M)

With operations and maintenance (O&M) being critical to the long-term performance of wind turbines, "remanufacturing" - restoring components to the same or better quality than their original condition - is likely to shape the wind sector’s approach to maintenance in the years to come.

Onsite replacement of blade root inserts is an advanced process requiring the right equipment and components to ensure a strong mechanical connection.

Three industrial work tents, each 100 m² in size, were set up at the wind farm. In the first tent, the blade was bored; in the second, the insert was replaced; and in the third, final finishing and quality checks were carried out.

The We4Ce and CNC Onsite method offers significant advantages: up to 60 percent cost savings, reduced downtime, and environmental benefits by eliminating potential blade waste and the need for transport, which typically involves high logistical costs and CO₂ emissions.

Efficient Boring in Fiberglass Rotor Blades

CNC Onsite designed and built a custom machine for boring out defective inserts from the root ends of turbine blades. The machine produces precisely dimensioned holes tailored to fit the new inserts.

“Boring into fiberglass wears down drill bits quickly, making the process demanding and time-intensive. As part of the project, we developed special drill bits to ensure high precision and efficiency,” explains Søren Kellenberger, Partner and Sales Director at CNC Onsite.

Infusion Technology Ensures Durable Insert Bonding

We4Ce uses its patented infusion technology to securely fasten the replacement inserts. Through an inlet pipe, epoxy resin is injected into the insert while a vacuum ensures even distribution around the cavity.

The insert at the root end of the blade is a safety-critical component that connects the blade to the hub. In certain blades, the insert is embedded in polyester. If the material shrinks or distributes unevenly during manufacturing, microcracks may develop, which over time can lead to larger fractures.

This weakens the bond and increases the risk of insert detachment - potentially causing serious blade damage.

We4Ce and CNC Onsite are currently preparing several upcoming projects with significant potential, including in Brazil and the USA.

About CNC Onsite

“Developing the world’s best technology isn’t enough. Without political will and support, Danish solutions risk never getting the place they deserve – neither at home nor abroad.”
Martin Gordon Andersen,
CEO at VisBlue

Denmark risks being overtaken by foreign players if we fail to invest strategically in our own technologies. That’s the view of VisBlue, who supports the Danish Technological Institute’s call for stronger political backing of Danish companies.

A Threat Landscape That Demands Technological Autonomy

With a global energy market marked by unrest, dependence on critical raw materials, and increasing electrification, energy security is no longer just a climate or export issue. It has become a matter of strategic independence and national security.

“It’s time we start thinking long-term and calculating more than just cost per kWh. We need to account for reliability, circularity, and strategic independence,”
emphasizes Martin Gordon Andersen.

Flow Batteries: A Concrete Danish Alternative

At VisBlue, we’ve developed a battery solution that not only supports the green transition – it also strengthens Denmark’s position as an independent and secure energy nation.

Our battery solutions:

• Are produced in Denmark
• Consist of non-flammable and 99% recyclable materials
• Are FREE from critical raw materials like lithium and cobalt
• Enable local, scalable, and safe energy storage

A Level Playing Field Requires Political Courage

We therefore support the Danish Technological Institute’s call for a far more ambitious industrial policy – one where public support, risk willingness, and export promotion are directed toward solutions that are both sustainable and strategically necessary.

“We have solutions that work – but we’re up against state-supported giants abroad. That’s an unfair playing field, and it requires political action if we’re to maintain our technological integrity,”
says Martin Gordon Andersen.

It's About Timely Action

We cannot afford to repeat the mistakes we’ve seen in other sectors – where Denmark invented the technology but failed to invest in scaling it. With flow batteries, we now hold a solution that benefits both the climate and the resilience of society.

“Denmark has a unique opportunity to commit to solutions that are secure, circular, and green. It simply requires us to choose it,”
concludes Martin Gordon Andersen.

Contact

Mia Voldum

Head of Marketing, Communications, Public Affairs & Sustainability

+4527230612

CNC Onsite, a Danish mobile machining expert, has delivered its custom-built ”Goliath” machine to wind tower manufacturer Welcon, where it is now milling 97 bottom tower flanges for Vestas’ 15 MW V236 turbines destined for projects in Germany and the Netherlands.Production began last month, April, and the first flanges have already exceeded flatness specifications, ensuring a perfect fit with the transition piece — enhancing reliability and design flexibility and significantly reducing costly post-production checks.

The milling process ensures that the tower and transition piece align perfectly, forming a flat, stable connection between the two flanges, a critical mechanical joint held together with bolts. By implementing CNC Onsite’s machining process, industry leading tolerances are achieved, which eliminates the need for heat straightening, a common post-production step to correct flatness issues, while also optimizing the maintenance of bolts during operation.

The precision machine,”'Goliath”, is a custom-built machine from CNC Onsite, specifically designed to ensure flat flanges for structural strength and fatigue resistance.

Bolted connections with long-term benefits

“On the first flange, we have achieved a global flatness tolerance of 0.21 mm. The required 1 mm for this project is already well below the common industry standard of 2.5 mm, so we are of course very pleased with the machines’ performance," says Soren Kellenberger, Sales Director and Partner at CNC Onsite.

”Ensuring a tolerance of 1 mm or better is a significant benefit when it comes to ensuring correct bolt tightening. With 160 bolts in a flange, reducing maintenance costs and downtime due to loose bolts, is a considerable cost saver."

Welcon will integrate the flange facing process as a standard manufacturing step, replacing the traditional heat straightening method, a controlled heating and cooling process used to correct flatness distortions after welding. By employing Goliath on these 97 bottom flanges, the tower manufacturer can ensure a faster, more uniform method.

Added value for Vestas

The consistent flatness across all flanges will provide Vestas, the customer of Welcon, with greater flexibility in flange designs and dimensions, as well as a broader choice of bolt sizes.

“The industry demand for fine tolerances is increasing. To meet flatness requirements, we need a machine-based process, as heat straightening cannot achieve the necessary precision."

“We also expect this to improve health and safety by eliminating manual work,” says Johnny Hauggaard Skov, Vice Director, Welcon.

“If applied throughout the industry on all flanges, from tower to transition piece, I believe this precision milling will offer a range of benefits. When all flanges are completely flat, it eliminates the costly measurements we have seen both at sea and prior to shipping. It will also provide design freedom, including the option of smaller and even maintenance-free bolts,” says Peter Sigfred Mortensen, Senior Specialist, Offshore Tower Structure, Towers R&D, Vestas.

Meeting new challenges in large-diameter flanges

As wind turbine tower flanges grow in diameter— now reaching 7.5 meters for Vestas' new 15MW turbines, the demand for even finer tolerances increases.

“It is a challenge to achieve the required precision for 4-5-meter diameter flanges. But on today’s seven-plus meter flanges the tolerances are even tighter. This combination of larger diameter and stricter tolerances makes it nearly impossible to meet standards with traditional methods,” says Soren Kellenberger, Sales Director and Partner at CNC Onsite.

Designed for flexibility and speed

Designed for efficient operation, the machine is mounted directly onto the flange. Using adjustable legs with hydraulic cylinders or optional electric actuators, the machine is securely positioned, allowing easy switching between different flange diameters.

Powerful electric motors enable fast, high-precision milling. The machine handles flanges from 6.5 to 10 meters in diameter in the standard configuration and can be adapted for larger sizes. Fully CNC-controlled, the machine can mill flat, tilted, and double-tilted flanges, as well as features like gasket grooves.

Goliath is the result of CNC Onsite’s more than 12 years of expertise in machining flanges for the wind industry. Developed and built based on this extensive experience, the new machine sets new standards for precision and efficiency.

The machine for Welcon is the third custom-built Goliath machine, designed for large diameter flanges, since its launch in 2022. It can be leased or purchased and is currently in use by offshore customers in Denmark and Spain.

About CNC Onsite

Headquartered in Vejle in Denmark, CNC Onsite designs and delivers high precision mobile machining for wind turbines including offshore foundations. Machines built by CNC Onsite are designed to be flexible using its proprietary "building blocks" approach, which means machinery can be built to match a range of tasks. CNC Onsite serves the onshore and offshore wind energy sector delivering as standard solutions: machining of large diameter steel flanges and blade root ends; specialized repair services covering yaw ring, inserts in blade root, rotor lock, generator shaft, bearing housing and threaded holes. Removal and replacement of worn and broken bolts round off the offering.