Secret Mission

Giant flanges in the Blade Test Centre hall. Wind turbine blades are set up here for testing

Hub North network's most secretive member is Blade Test Centre. Management and employees safeguard work processes but also emphasize openness and active participation in the business network.

The address is hard to find. Signs and administration buildings are not prominent either. The production hall is, however. The 26-meter-high building at the Port of Aalborg houses the Blade Test Centre, a business whose ambitious strategy is to be the world's leading tester of wind turbine blades.

The products are well wrapped up here and a visitor is not let out of a meter's reach for more than a few seconds. Outside, the contours of a simple wind turbine blade can be made out. It is wrapped like the latest top model of an Audi prototype just before a tradeshow launch. Cameras are naturally forbidden.

Who are your customers?

“Well, I can't really tell you about that either. Only that 80 percent of revenue comes from abroad”, says Carsten Skamris, the friendly, but also deprecating Managing Director of Blade Test Centre.

He is an engineer and comes from Risø's test center in Sparkær in the municipality of Viborg. Blade Test Centre was founded in 2005 with 15 employees after breaking out from Risø research in Sparkær when testing became more and more industrialized.

“Risø would rather spend money on research than on steel and concrete. Now the test center is so commercial, and that is where it belongs, too”, says Carsten Skamris.

Blade Test Centre is a general corporation owned by three parties: DTU Risø, Force Technology and Det Norske Veritas. The most important characteristics of the employees are advanced technical skills and a high degree of credibility.

Fatigue Testing
A closely monitored tour of the secret test halls reveals that the blades have a clear coat of paint that allows a peek into the entire structure. Many different measuring instruments are taped firmly to the test blades here and there. A single 50-meter long blade is wrapped all the way around and along its length in military green plastic. Up under the 25-meter high ceiling, a 60-meter long wind turbine blade is set in position. Looking up from below at the impressive structure it is hard to imagine that it can be made to sway 15 meters up and down.

“It needs to be able to do that. The small turbines from 20 years ago were unbelievably stiff and did not have much resistance ability. The blades at that time were typically 8.5 meters long. The Tvind turbine was gigantic for its time and had 30-meter blades. Today, the blades are twice that long and they are getting even bigger. That's why they need to be able to withstand huge loads and also be able to sway many meters from side to side. Towers and blades sway constantly on turbines today”, says Carsten Skamris.

The giant blade up under the ceiling will be tested for two to three months. It is a prototype for the next generation of wind turbine blades – somewhere or another out in the world. It is tested for deflection, rigidity and load strength. Fatigue testing takes place using small constant wind gusts that cause the blade to vibrate. It is also exposed to a load equal to that of a hurricane. The goal of the test is to ensure that the blade can last for approximately 20 years.

The blades are mounted on gigantic circular steel flanges, which in turn are mounted on a concrete base weighing 1150 tons. The flanges can be compared to a type of giant bathroom scale. A force of up to 50 tons is generated. Technicians can crawl into the wings from the rear of the steel flanges.

Business
Blade Test Centre has facilities that can test wings up to 85 meters when that time comes. The length of the hall only needs to be expanded a few meters.

The price for testing a wind turbine wing can be DKK 600,000.00 for a small wing that only needs to be in the hall for a month for a static test. At the upper end, the price can be four million Danish kroner, for example, for comprehensive testing of a 60-meter long blade over a period of six months.

“We have enough to do but we would like to have a more even distribution of orders”, says Carsten Skamris.

What do you get our of a commercial network such as Hub North?

“Businesswise perhaps not so much because 80 percent of our customers are from abroad. But it is always good to have a network, us included. It's always an advantage to be in an environment where something is happening. For example, we got a whole new set of subcontractors when we moved from Sparkær to North Jutland and it's always good to know what each individual one does in a region of the country. Who is here and what do they produce? That's good to know”.

“In a broader sense, of course it's necessary to be wary of isolating yourself in a specific area, but I have gotten the clear impression that Hub North does not want to isolate itself. The network is available for all of Denmark, certainly for the entire wind industry”, says the Blade Test Centre director.