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Wind and solar currently contribute 10 per cent of energy production globally. The renewable energy market has grown enormously, giving way to startups with great new ideas for energy production.

For five consecutive years, Rune’s childhood summer holidays were spent in a cottage village in Frederikshavn. Not only to enjoy the camping and the beaches of Northern Jutland, but also to keep an eye on the prototype of a wave energy plant that the family had developed in a small, family-owned business.

»I went to the first tests as a young boy. It’s been my whole life,« says Rune Pilgaard Bloom.

The green family business already started developing its wave system 15 years ago. Invented by father Henning Pilgaard, and first tested as a prototype together with Aalborg University in 2009.

»He got really good results – in fact, better than expected – and then the journey went from there,« says Rune Piilgaard Bloom.

In 2015, the first full-scale prototype was ready. And although the family business went through the major upheaval of founder and father Henning Pilgaard passing away shortly after, the family dream is now in its decisive phase: potential customers are ready once the plant has proven its viability, and Crestwing expects to have the first 10-megawatt park installed by 2025.

»Hardware is expensive and takes a long time to develop, but we are now at the point where wave energy is close to proving itself on commercial terms. It’s not a question of if it happens, but when it happens,« says Rune Pilgaard Bloom, who has been CTO of Crestwing since 2020.

Rune presenting Crestwing at the Ocean Renewable Energy Conference in Oregon, US, as part of a EU delegation.

Crestwing: Timeline

  • 2007: Inventor Henning Pilgaard founds Crestwing with his wife Ruth Bloom.
  • 2009: The first prototype of the wave system is tested in collaboration with Aalborg University.
  • 2015: Production of Tordenskiold, Crestwing’s first large-scale prototype, begins in Frederikshavn.
  • 2016: Henning Pilgaard passes away. Ruth Bloom takes over the company.
    2018: Ruth Bloom completes production of the Tordenskiold and begins offshore testing.
  • 2020: Rune Pilgaard Bloom (trained physicist at Aarhus University) joins Crestwing as full-time CTO.
  • 2022: Crestwing is proving commercial potential and has Letters of Intent from Shell, Robinson and YSEMD.
  • 2025: Expects to have the first 2.5MW commercial wave plant connected to the grid.

Windmills for everyone

While Crestwing is proving the potential of wave energy, startup KiteX has a new approach to wind power. It has harnessed a special cord drive to develop a small, flexible type of turbine that requires 90 per cent fewer materials to produce than conventional turbines.

»We wanted to make the world’s lightest wind turbine. We started with the smallest turbine we could make that still made commercial sense, and here we identified campers who could set it up and power a refrigerator and a computer in their RV,« explains Christoffer Sigshøj, co-founder of KiteX.

The camping mill, which weighs 12 kg and produces 250 watts, went on sale on Kickstarter last year, where the startup raised 700,000 DKK. The first units have just been shipped, but the ambitions are much bigger. Within a few years, KiteX expects to sell 40,000 mini-mills a year. And even that figure is just a stepping stone to the big goal: the next generation of domestic wind turbines.

Kitex' portable wind turbine next an RV on the beach.
The special cord drive design enables Kitex to produce a wind turbine with just 10 per cent of the materials used by a conventional turbine. Kitex estimates that there is room for 40,000 household turbines in Denmark. On a global scale, they do not consider it unrealistic that they can produce a million household turbines a year.

»Vestas is good at what they do, and they deliver a lot of power. But it’s also mega-projects every time. It’s left a whole undergrowth of people who just want their own windmill to produce power,« says Sigshøj.

KiteX has a household turbine on the drawing board that, thanks to its special design, requires far less materials to build, can be efficiently shipped around the world and is easy to install. The startup expects to deliver it for just DKK 150 000 – a quarter of the price of today’s most popular domestic turbines.

»We’re not going to replace Vestas, but there’s a huge market for residential turbines. A recent report estimates that 670 gigawatts could be installed,« says Sigshøj.

With a price that is significantly lower than the competition, he does not consider it unrealistic that KiteX could take 20 per cent of the market.

»The dream is that we will open the KiteX Giga Factory next to Elon Musk down in Texas,” Sigshøj says with a grin, adding, “And then we will make a million turbines a year. It will really make a difference when you can replace a diesel generator with a turbine you can set up at home in a day.«

Room for more

In 2021, wind and solar generated more than 10 per cent of electricity globally for the first time, according to the Globel Electricity Review. And renewables capacity is still growing significantly: in 2021 it increased by 6 per cent, equivalent to 295 GW, despite pandemic and value chain challenges.

While neither Kitex nor Crestwing have any ambitions to outcompete Vestas, the growing market and demand leave ample room for complementary solutions. And Rune Pilgaard Bloom sees the wave turbine as a complementary product to future wind-based energy islands.

»One of our most profitable cases is to put our plant among the wind turbines in a park, so we use the area better. If you install our plant around the park, it reduces the wave height, so you have a wider service window to repair the wind turbines,« says Rune Pilgaard Bloom.

Crestwing’s large prototype measures 30 metres and weighs 65 tonnes. The large commercial plants are 120 metres long, weigh 1000 tonnes and have a 2.5 megawatt generator. The plant is based on known solutions and technologies from the maritime sector, and therefore Crestwing also believes that it can facilitate the production of plants equivalent to 100 megawatts per year through existing subcontractors.

As the wave system is based on barges, it also allows transformer stations or solar panels to be placed on the barges, giving the energy island a more stable output. However, first the plants must mature from prototypes to commercial installations, of which none yet exist on a large scale worldwide.

If Crestwing succeeds, it has already received letters of intent from interested customers, including Shell. For the startup, the goal is to begin construction of the first commercial park in 2025. A park that will consist of four turbines producing 10 megawatts for the grid by 2026 – at a price competitive with offshore wind turbines.

»The potential is huge, so now it’s time for Denmark to jump on the wave. We have 4-5 good wave energy plants under development in Denmark that have come quite far. We could have a journey in Denmark that could be as wild as our wind journey. We just need to get behind the sector,« says Rune Pilgaard Bloom.

About: Wave energy

  • Wave energy harnesses the energy of ocean waves using special equipment.
  • Experience shows that the method can produce energy both at low wind speeds, when the waves are small, and in stormy weather.
  • Denmark has a handful of wave energy plants set up as demonstration projects – including the Crestwing plant.
  • According to the Partnership for Wave Power, wave energy has the potential to cover a significant part of Denmark’s energy consumption. However, developing wave energy and making it competitive will continue to require a determined and long-term effort.

Source: Danish Energy Agency