Halvor (29) is heading one of the world’s most pioneering renewable energy projects

It all started 16 years ago with an idea drawn on a napkin. Today, five 253-metre-tall wind turbines are moving out to sea, off the coast of Scotland. 

“It is just so impressive what we have managed to do out here,” says Halvor Hoen Hersleth, as the wind almost blows him over.

The young engineer is standing on the coast in north-east Scotland, outside the town of Peterhead. The world's first floating windmill park, Hywind Scotland, is located 25 kilometres away, out in the North Sea, and comprises five huge wind turbines with enormous potential. It has been fully operational since October last year and now generates power for 20,000 households.

“The sea covers around 70 per cent of the earth’s surface and is an underutilised energy resource. Almost 80 per cent of the potential is in deep waters, which is ideal for Hywind,” says 29-year-old Halvor, who believes that Statoil's wind technology can produce clean energy on all the seas in the world in just a few years.

Why floating wind power is the future

The main advantage of floating wind turbines is that they can be built in more places than conventional wind turbines, which need to be anchored to the seabed—places where the water is deeper and there is more wind.

“Bottom-fixed wind farms can only be built in areas with favourable seabed conditions, the right depth and good wind conditions. With floating wind turbines, we are no longer restricted to shallow waters. This opens up new markets, meaning wind power plants can be built near areas with a high demand for power,” says Halvor, and goes on to give us some examples:

“The west coast of the USA, Japan and Hawaii are all places that need a lot of energy and that are consistently windy, but where the sea is very deep. Floating wind power is ideal for these areas,” he says. 

Hywind

  • The world's first and the leading floating offshore wind solution.
  • An important part of Statoil's investment in renewable energy.
  • Statoil has invested NOK 2 billion in Hywind Scotland together with its partner Masdar.
  • This unique offshore wind technology consists of a mixture of available technology and new patents developed and owned by Statoil.
  • Came on stream 25 kilometres off the coast of Peterhead in Scotland in October 2017.
  • Five floating wind turbines that are 253 metres tall.
  • Generates power for 20,000 households in Peterhead.

Imaginative surfing enthusiast

The 29-year-old from Ås has always wanted to be an engineer. Once Halvor had completed his military service, he studied energy and environmental engineering at the Norwegian University of Science and Technology, NTNU. After a summer project at Statkraft, where he worked with offshore wind power, there was no doubt what he wanted to work with after graduation.

“I have always liked to build and make things. I have a pretty good imagination as well. In addition, wind power and renewable energy represent a great opportunity for building the future.”

Halvor joined Statoil as an electrical engineer at the age of 24, but he transferred to the renewable energy department during his first year. He finds that he has been given many development opportunities in the company, and he has never felt that his age has been an obstacle. A keen surfer, he quickly became involved in the Hywind project, and he had the primary responsibility for getting everything ready for the start of operations during the project execution phase.


It's hard to appreciate the scale of the turbine nacelles until you see them up close Photo: Jan Arne Wold

Each turbine towers 253 metres (830 feet) in the air—more than 100 metres taller than the London Eye. Photo: Jan Arne Wold

The five giant turbines are now powering 20,000 Scottish homes Photo: Øyvind Gravås/Woldcom

Halvor always wanted to be an engineer. After military service, he studied energy and environmental engineering at NTNU Photo: TRY

It's hard to appreciate the scale of the turbine nacelles until you see them up close Photo: Jan Arne Wold

Each turbine towers 253 metres (830 feet) in the air—more than 100 metres taller than the London Eye. Photo: Jan Arne Wold

The five giant turbines are now powering 20,000 Scottish homes Photo: Øyvind Gravås/Woldcom

Halvor always wanted to be an engineer. After military service, he studied energy and environmental engineering at NTNU Photo: TRY

“The test period started off the coast of Karmøy in 2009. Prior to that, many capable people had already been working for several years to develop a demo turbine. We then operated this turbine and collected data, to make sure it worked before we went any further. We completed eight years of error-free operations, and the turbine performed well above our expectations.”

After a successful test period, Hywind Scotland came onstream in October last year. Halvor was made plant manager then, which means that he has overall responsibility for the operation of Hywind Scotland.

How have the first few months been?

“Recently the turbines have been stable and delivered above expectations, so it has been a very good start. But we have also experienced some challenges. The weather conditions have been very rough, so if a turbine stops, it can be difficult to perform maintenance.”

Halvor Hoen Hersleth

  • 29 years old. Grew up in Ås, in Akershus County.
  • Studied engineering at NTNU in Trondheim.
  • Plant manager for Hywind Scotland.
Portrait halvor hoen hersleth

Why Statoil has been successful

Not long ago, floating wind power was just an ambitious dream. The idea was conceived in 2001 when it was drawn on a napkin. Quite simple on paper, but much harder to implement in practice.

“There is a reason why Statoil is the only company with a floating wind farm,” Halvor laughs.

The idea is based on the technology that is used in the oil and gas industry. A spar buoy, a long cylinder with a net weight of approximately 2,200 tonnes and approximately 8,100 tonnes of ballast, holds the turbine upright in the water. It extends 78 metres below the surface of the sea and is anchored to the seabed by three anchoring piles.

In addition, Statoil has developed a motion controller, which is the cornerstone of the Hywind technology. This adjusts the blades according to the wind to reduce movements in the wind turbine and increase the production of power.

Why has Statoil been successful with this project?

“I think that the oil and gas expertise that Statoil possesses has been extremely important to the development and implementation of Hywind. It also has to do with willpower, financial strength and innovation. You have to believe in the project and make an investment, and that is what Statoil does.”

  • How Hywind was born

    The best ideas often happen when you least expect them—and when you’re not at the office. Two becalmed sailors started to doodle on the back of a napkin, and the rest is history.

Close to the problem and the solution

Floating wind power is part of the transition that Statoil is currently undergoing from a company focused on oil and gas to becoming a broad-based energy company. The goal is to make floating wind power a competitive source of renewable energy. Statoil has invested NOK 2 billion in the Hywind Scotland project.

"Oil and gas are part of the climate problem, and we have to integrate more renewable energy and come up with new solutions. In this respect, working for Statoil is ideal. You are close to the problem, but even closer to the solutions. There are few companies capable of working with renewable energy to the extent that Statoil does.”

Now that the technology is working in the North Sea, we are going to venture into new waters. Halvor says that they are working on other Hywind projects now, and that they hope more projects will be established during the next couple of years.

"Hywind Scotland is a springboard, and it would be very disappointing if no new Hywind projects are established. Now we have four years outside Peterhead, during which we will test, learn and prove that floating wind power works very well. It shouldn't be a problem,” Halvor smiles.

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