Sky's the limit?

Two of MHI Vestas’ new giant 8 MW wind turbines are being installed for final testing in the town Måde south of Esbjerg. There are rumours of 10 MW turbines making their way to the market. How much larger can wind turbines grow? 

Eighteen times the capacity and blades more than four times the length. That is, in short, how much offshore wind turbines have evolved since the very first turbines were erected at the Vindeby test site in 1991 until today where the world’s largest wind turbine, located at the Østerild test site in Jutland, has a capacity of 8 MW.  

The world record belongs to MHI Vestas with its 220-metre-tall V164-8MW turbine, the first of which was erected in 2014. Two V164-8 MW turbines are now being installed at Måde, south of Esbjerg, for final testing and adjustment before they will be ready to operate offshore.

MHI Vestas has great expectations for its 8 MW platform. In October 2014, the company set a new world record for energy production when a single wind turbine produced 192 MWh in 24 hours – enough power to supply 30 Danish households for a year.

According to Bo Bjerregaard, Director of Pre-assembly and Projects at MHI Vestas, these huge turbines offer distinct advantages over the smaller models.

“Larger and more powerful turbines will directly contribute to lowering the price of offshore wind energy,” he says, explaining that the bigger the turbines, the fewer units are needed to produce the same amount of energy. Relatively speaking, this could reduce costs through fewer foundations and less turbines to maintain. 

Towards 10, 15 or 20 MW?

Several other manufacturers have also announced plans for new giant turbines. Siemens currently has a 7 MW turbine on the market and recently voiced an ambition to develop a 10 MW turbine by 2020. MHI Vestas has previously sent similar signals. Several analysts have indicated that the future could see turbines of 15 MW or 20 MW capacity.

Even larger turbines may also be realistic, but MHI Vestas is taking one step at a time, according to Mr Bjerregaard:

“Since we set up MHI Vestas (in 2014 –ed.), the offshore market has become much more competitive. This has moved our focus away from simply building larger turbines, so now we’re thinking more about how we can lower the costs of offshore energy. We are confident that our V164-8 MW turbine will bring us a big step forward towards achieving that goal,” he says.

“Right now, our focus is to deliver the V164-8 MW turbine for its first project in 2016. Of course, building even larger turbines is technically doable, but before we invest the resources necessary to build an even more powerful platform, we have to have a more concrete and stable project pipeline,” he continues.

Size matters – but it’s not everything

Although wind turbines have truly followed the Olympic motto of faster, higher and stronger, the giant turbines also come with challenges. As turbines grow, they become heavier. This creates more and tougher requirements to both the structure and the value chain. 

“The challenge is to develop a turbine that is both lighter and stronger. For the V164-8 MW, our focus has been to reduce the weight of the nacelle by using carbon fibre in the blades and putting the power converter module in the tower. Erecting large turbines also poses a challenge because you need larger ships and more powerful cranes with sufficient capacity.”

Mr Bjerregaard emphasises that new giant turbines do not mean that smaller turbines will be phased out.

“We are very confident that the 3 MW platform will continue to have a role to play. In 2017, we will be installing 3.45 MW turbines, 117 of them, at the Rampion offshore wind farm in the UK. Going forward, we believe that the 3 MW turbine platform will be key for MHI Vestas in developing new markets outside Europe.”


EWEA: Standardisation will lower costs

Will new giant wind turbines lead to lower costs? Perhaps. But the real key to making offshore wind energy competitive lies in standardisation and specialisation, according to EWEA.

In principle, there is no limit to how large offshore wind turbines you can build. The question is whether it pays off. Bringing down the price of offshore wind energy depends on joint industry initiatives, explains Kristian Ruby, Head of Political Affairs at the European Wind Energy Association (EWEA). 

“We still haven’t reached the physical limit regarding how big wind turbines can get. We know that some manufacturers are currently working on developing a 10 MW platform, and we expect to see the first of them as early as next year,” says Mr Ruby.

“But the extra benefit from building the bigger turbines will depend on whether the power can be transferred to the grid, how the new turbines are designed, how much they weigh, the kind of foundation they will need, and logistical factors. These are still unknown factors. Plus there is constant innovation in the industry.”

Three essential factors

It is no secret that the offshore wind industry is in a race against time to make this source of energy competitive. Several of the major players have committed to cutting costs by up to 40 per cent by 2020. While onshore wind has already become the cheapest source of power in Europe, cheaper even than both coal and natural gas, the price of offshore wind energy is still a good deal higher.

The ever-increasing capacity of offshore wind turbines is helping to reduce the price of offshore wind energy. However, Kristian Ruby believes three different factors will be key for the industry to drive costs lower: more specialised sub-contractors specialising, standardisation across the industry, and more innovation in offshore wind farm components other than turbines. 

“The logistics chain clearly has cost-saving potential. Not too many players in today’s market can handle the big turbines, but as the market evolves and players become more specialised, prices will fall,” he says.

Standard solutions could reduce costs by 10 per cent

It is also necessary to standardise across the industry, both in terms of components and processes, emphasises Mr Ruby.

“If the industry can agree on standards for blade length or towers, or even the very small things such as the colour of the platform railings and the type of safety shoes the workers should wear, it will pave the way for lower costs,” he says.

If the industry could agree on joint standards, it would allow sub-contractors to develop standard solutions instead of having to start from scratch for each single project. That would provide the potential for scale benefits.

“It is a question of ‘every little bit helps’: everything from the way turbines are tested to the safety course requirements. According to people in the industry, standardisation has the potential to cut costs by up to 10 per cent,” Mr Ruby explains.

A maturing industry

Lastly, Mr Ruby points to the balance of plant factor, which in simple terms means everything in an offshore wind farm, but the turbines themselves.

“Innovation is high on the agenda for the wind turbine manufacturers, but there is still a potential to increase efficiency in foundations, transformer stations and the entire infrastructure connecting the offshore turbines with the grid onshore.”

Although operators and manufacturers alike must navigate in extremely competitive markets, the people at EWEA believe that the industry should be able to agree joint standards within the foreseeable future.

“The industry is in a maturing phase right now, and the need for standards is increasingly being recognised. There are a lot of interests at stake, and we will see some tough fights over how the standards should look, but I’m confident we will see the first standard solutions within the next five years,” says Mr Ruby.


Port of Esbjerg is ready for giant wind turbines

There is no limit to how big the wind turbines of the future can be –  the Port of Esbjerg is ready to handle the new giants. Flexible harbour areas are crucial, according to the Port of Esbjerg’s COO Henrik Theilgaard.

Wind turbines have grown in size and more than quadrupled in capacity during the period the Port of Esbjerg has been involved with offshore wind turbines. Today, the largest turbines have blades up to 80 metres in length, towers than can measure up to 90 metres tall and foundations that can weigh more than 1,000 tonnes. This creates new demands on ports, spanning from the quays to the cranes, access facilities and the seabed.

According to COO Henrik Theilgaard, the Port of Esbjerg is well prepared for the giant wind turbines of the future: 

“Wind turbines are evolving rapidly now. It’s our job to make sure that we are prepared. Fortunately, the Port was visionary enough ten years ago to begin investing in developing large areas that today make up the East Port.”

Quay areas customised for large wind turbines

The East Port consists of a total of 1,260 metres of quay and almost 600,000 square meters of flexible space – equal to the size of about 90 football pitches – much of which is currently being used for the wind turbine industry. In addition, the area can be expanded further as the need arises. 

Both the quays and the port areas have been future-proofed: they have a height of 4.5 metres over DvR90 on the quay and of 5 metres over DvR90 behind the quay. This means that the East Port is built to handle the expected higher water levels that could result from climate change. The water depth at the quay is 10.5 metres meaning that the area can accommodate several of the largest wind turbine installation vessels at the same time, and the 34 metre wide ramp makes it easy to load even the biggest wind turbine components.

Room for multiple projects at the same time

The Port of Esbjerg clearly demonstrated the excellent conditions the East Port offers the wind turbine industry in the spring of 2015 when it was base port for six major offshore wind projects at the same time, with simultaneous activities ranging from pre-assembly to components being shipped off.  

Flexibility is key, explains Mr Theilgaard. It is rarely a one-size-fits-all solution that is needed for the major projects. Instead, it is very important to interact closely with customers to define their specific needs to determine exactly what they need for each project.

“We work very closely with our customers. The main objective for us as an infrastructure provider is to ensure that we have sufficient areas and quay space for our customers and to make sure we can accommodate their specific needs. The best solutions are the ones we develop together with our customers,” says Mr Theilgaard.

“When it comes to the space available, we have no problem whatsoever with bigger wind turbines.”

Even better road access

On the other hand, transporting wind turbines to the port could turn out to be the biggest challenge. The bigger the turbines, the bigger the road access requirements. This is one of the reasons why the Port of Esbjerg teamed up with the Danish Road Directorate in 2012 to have the E20 motorway extended all the way to the port

An extension of H.E. Bluhmes Vej at the north end of the port is scheduled to open by the turn of the year and will allow these oversized transports to bypass the city and go straight to the port area.

The Port of Esbjerg is working with Esbjerg Municipality to open a new easterly route for special transport that would shorten the route for large transports by 10km while directing heavy traffic away from the city centre.

Growing offshore wind turbines

  • Built in 1991, the world’s first offshore wind farm, Vindeby, was a pilot project consisting of eleven 450 kW turbines from Bonus Energy, each with a rotor diameter of 37 metres.
  • Eight years later when the first full-size wind farm, Horns Rev I, was built, the average wind turbine had already grown much larger: Horns Rev’s eighty 2 MW Vestas turbines each had a rotor diameter of 80 metres.
  • In the spring of 2014, MHI Vestas launched its most powerful turbine to date: The 220-metre-tall 8 MW turbine has a rotor diameter of 164 metres and is currently undergoing final testing.
  • Siemens, Adwen and Alstom are also competing in the race to manufacture large wind turbines. Siemens and Alstom both have 6 MW turbines on the market while Adwen has a 5 MW turbine. Siemens recently launched an upgraded version with 7 MW capacity, and Adwen is currently testing an 8 MW turbine.


This is a translation of the Danish articles published in Port of Esbjerg Magazine 1, 2015. 

Back to news overview