Wind - powerful business

Two kilometres from the Nexans factory in Grimsås, there are 13 wind turbines in action with the capacity to supply 30,000 households with electricity. Nexans delivered both the power cables that conduct the energy to the electricity grid and the fibre cable for controlling the turbines. Wind power is an increasingly important business for Nexans Sweden.

Per Lundgren, Sales Manager Infrastructure Telecom and Electricity Network at Nexans only needs to look out the window from his office to see the wind turbines at the border between the municipalities of Tranemo and Gislaved.

– It is powerful, especially when I enter Grimsås in the mornings, he says.

Per got involved with the project back in 2009 after visiting the Kraftö Vind AB project and contributing to plans to build a wind farm near Grimsås. At the time, the the idea was that they would be ready in 2013-2014.

However, the high price of electricity licenses at the time stopped construction. Then came a new and improved type of turbine with a taller tower but it required a new license, so the project dragged on slowly. When it was time to build the turbines, Siemens Gamesa Renewable Energy was the chosen manufacturer and for Per Lundgren the only contender for power cable supplier was Nexans.

– The symbolic value of the fact that the turbines are only two kilometres from our factory is clear.  

The wind turbines now have a tower height of 120 metres, a rotor diameter of 130 metres and were built and connected with 14 kilometres of 36 kV power cable from Nexans. 12 kilometres of Nexans optical cable handles control and communication between the turbines.

The power cable also conducts the electricity further on to regional power grids. This wind park is different to most as it has two recipients of its energy.

– Ten of the wind turbines supply electricity with a voltage of 33kV to the newly built transformer station, where the voltage is transformed to 40 kV and output is conducted to the Vattenfall regional power grid. Three of the turbines supply 10 kV voltage electricity to E.On via the E.On station located close to the Nexans factory. In this way, the use of licenses is fully optimised, as is the power of the wind as a source of power, says Mats Gyllklint, Construction director at Kraftö Vind AB.

Kraftö Vind AB develops and builds wind power. This work includes identifying suitable sites, negotiating with landowners and working with licensing processes before construction. According to Mats Gyllklint, the Grimsås project has worked very well.

– The logistics of this type of project are difficult to say the least - the propellors are 65 metres long. For this project, the tower components came from the port of Karlshamn, while others were transported by road from the manufacturer in Denmark. About ten kilometres of new road has been built and crane installation areas established in the project, says Mats Gyllklint.

Grimsås Vindkraft AB, which is the company name for the wind turbines delivers an output of 42.4 MW to the electricity grid. This corresponds to consumption for around 30,000 normal households. The company is currently owned by Marguerite, a French investor undertaking its first investment in renewable energy in Grimsås. Element Power Ltd manages the operation. Wind power is playing an increasing role in electricity production and today accounts for eleven per cent of Swedish electricity, according to figures from the Swedish Energy Agency. It also means that wind power is becoming increasingly important to Nexans.

– Wind power is about 20 per cent of our electricity network business. The facilities use a lot of cable, especially the large parks in the wilderness of Norrland. Our major products for wind power are 36 kV power cable and fibre cable for control and information. A key strength is that our power cables have built-in pipes that enbale fibre cable to be bllown in after the power cable has been laid, says Per Lundgren.

In addition, Nexans has been involved in creating the Wind in Road placement method. Nexans recommends that when building roads in a wind park, a pipeline is laid for cables in the road, which is then protected by the road surface. Power cable can then be pushed into the pipeline. The alternative is to build a cable trench next to the road. But then there is a risk that the cable can be destroyed by forest machinery or something else because the ground there is looser. The lifespan of wind turbines is currently estimated at 25-30 years.

– Wind power is still undergoing rapid development on the technology side and we are seeing more efficient technology with less service needs and a lower cost per megawatt. The quality of the cables that are part of the development of vital importance. Each cable fault means that the system must be taken out of operation and that costs money. We know that Nexans is a brand that is doing well in this sector, says Mats Gyllklint at Kraftö Vind AB.

The wind farm in Grimsås in numbers

• Number of wind turbines: 13.
• Power in MW: 42.4.
• Lifespan this year: 25-30.
• Power cable in kilometres: 14.
• Fibre cable in kilometres: 12.
• Kilometres between power plants: 10.