Taking Wave Energy to the Bank

While wave energy is a generation or more behind its offshore wind cousins in the quest to deliver reliable power to utility scale, a Swedish company has its eyes on the prize and is progressing toward a bankable solution by 2024. Patrik Möller, CEO, CorPower Ocean discusses with MTR the company’s plan and progress.

By Greg Trauthwein

CorPower is seeking success in the wave energy production arena, arguably the most challenging ‘renewable’ energy arm due to the hostility, unpredictability and instability of working in the corrosive ocean environment. A successful system must be rugged enough to survive the ocean’s toughest conditions, yet flexible to generate power when conditions are calm.

At CorPower, Möller is leading a team that is purposefully taking its time to prove the concept, the technology, aiming to become a leading OEM and deliver a system that is both attractive to the investment community, providing utility scale production.

Since 2012 CorPower has been embarked on a five-stage process to design, test and deliver its Wave Energy Converter (WEC) solution. Currently in ‘stage three,’ Möller said the company to date has gotten funding of about $38 million, and will require an additional $65 million to complete stages four and five and bring the system to market in 2024.

“The structural efficiency of wave energy is being improved by a factor of five (10MWhr/per ton of equipment installed in the ocean). That is in line with the best floating wind concepts out there.”

Patrik Möller, CEO, CorPower Ocean

“Wave energy has not followed the same curve of acceleration as offshore wind,” Möller readily admitted. But he sees promise in the broad uptake of offshore wind, as well as the interest building around floating wind production. “It’s fantastic to see the level of deployment of offshore wind, particularly floating wind coming on line in recent years as a bankable technology. It’s really amazing.”

In evaluated the wave energy industry as a whole, Möller estimates that there have been two tall hurdles to cross to bring the technology online as a significant contributor to power the world.

Historically, the devices have either broken in storms or they’ve just not produced enough electricity to make it a viable business case, said Möller. Regarding survivability, CorPower is introducing a new way to protect devices in the largest waves he said, introducing a function to wave energy similar to wind energy; pitching the blades in storms. “Every commercial wind turbine has the capacity to pitch the blades to protect from overspinning in the fiercest wind conditions,” said Möller. “That has been a capability that has been missing in wave energy, so we’re now adding that to our devices. The second challenge is advanced phase control technology that strongly amplifies the response to the regular waves. By amplifying the response to wave to enhance the power capture.”

If his teams calculations are correct, and they are presently building a full-scale model, the C4 buoy which is a 9m diameter device designed to generate 300 kW, the result will be a system that, on average, captures five times as much energy over the year compared to the amount of machinery installed in the ocean.

“The structural efficiency of wave energy is being improved by a factor of five,” he said. That’s 10MWhr/per ton of equipment installed in the ocean which Möller believes is “in line with the best floating wind concepts out there.”

We have completed three stages; in the third stage we built a half-scale system that we demonstrated in the Orkney Islands in norther Scotland

How close is Corpower’s technology to commercialization?

Corpower is currently fabricating our first commercial scale system, which will be dry-tested in a bespoke test rig with simulated wave loading in Stockholm before being deployed in the ocean during second half of 2021. We recently launched a $18.8m project in northern Portugal with plans to develop an research and development, manufacturing and service center. mission is to successfully introduce certified and warrantied WEC products to the market by 2024, making wave energy a bankable technology that can attract mainstream renewable project finance. Corpower’s knowledge center in Viana will drive the development and mass fabrication of WECs, laying foundations for future high-volume operations. Over the coming years we will collect substantial amounts of data to ‘prove’ our technology, with an overall aim of successfully complete the HiWave-5 demonstration phase with a competitive and certified product.

What kind of LCOE do you foresee?

Corpower has a clear path to a LCOE below $35/MWh. From first pre-commercial installations in 2024/25, the LCOE is projected to drop below $118/MWh after 150MW installed, and $70/MWh after 600MW installed by 2030.

How will Corpower succeed in Wave energy when so many others have failed?

Corpower is confident in its ability to commercialize this new class of WECs. Our structured five-stage product verification program is recognized as best practice in the sector. The program involves a step-by-step verification process ensuring the business case is supported by the physical and economical metrics in each stage from small scale models (2012) to full scale array product (2023). This provides a clear path to reach a bankable product. A key part of the strategy involves dry testing each machine in controlled simulated wave loading on-land, to fully debug and stabilize the machines prior to ocean deployment. The WECs will undergo a further certification process with DNV-GL and independent third-party performance validation from EMEC and WavEC.

What’s your timeframe?

In line with Corpower’s LCOE forecast, we expect our new class of WECs to be highly competitive with existing ocean technologies within the coming decade and with wind and solar by 2030.

That is, of course, the ideal. What needs to be done to get there?

Ring fenced revenue support for ocean energy is essential to accelerate deployment of the first 100s’ of MWs by 2025-3030. This comes at a low cost, benefiting countries supporting the development such as the UK, Ireland, Portugal, France, U.S. and Norway. The technology also requires validation from independent academic and scientific spheres combined with strong support of energy developers to demonstrate market confidence. Corpower’s technology is already receiving broad support across Europe from organisations including InnoEnergy, the Swedish Energy Agency, European Commission and Wave Energy Scotland. Major players within industry are also engaging including EDP, Simply Blue Energy, ENEL, and ABB.

Inside the CorPower’s WEC

According to Patrik Möller, CEO, CorPower Ocean, it remains incredibly challenging to harness wave energy or convert it into electricity in large volumes. Waves not only roll past devices, they also bob up and down and converge from all sides in unpredictable seas. The hostile ocean environment with huge swells, destructive waves, high winds and corrosive saltwater also present major challenges for wave energy developers. A successful wave energy generator must prove to be both durable and reliable. There have been many attempts to design a device which effectively captures wave energy including writhing snake-like attenuators and devices mounted on the ocean floor.

Wave energy devices have historically either broken in storms, or they have not produced enough electricity compared to their cost to make it a viable business case. By introducing this new class of phase-controlled WECs, we are changing that picture. CorPower WECs can produce five times more electricity per ton (10MWh/t) than any other known wave technology by combining:

Storm survivability by a novel protection mode making the device transparent in storms, similar to a wind turbine pithcing the blades in storms; and
Strongly amplified power capture in regular sea conditions by advanced phase control technology.

CorPower’s WECs provide a unique solution. Our WECs are essentially heaving buoys which float on the surface absorbing energy from ocean waves. The buoy is connected to the seabed using a tensioned mooring system. Special technology is used to make the compact devices oscillate in resonance with the incoming waves, strongly amplifying the motion and power capture and harnessing energy from the rise and fall as well as the back and forth motion of waves.

The resonant WEC has four significant patented features:

Pneumatic pretension system. Makes the device transparent to storm waves, and brings down the required materials by 40% compared to a conventional gravity-balanced WEC, reducing CAPEX;
WaveSpring phase control technology, providing 300% increase in Annual Energy Production (AEP) for a given buoy size;
Cascade gearbox technology, enabling robust conversion of the amplified linear motion into rotation with low losses;
Composite hull technology, eliminating corrosion issues from salt water and provides long lifetime.

CorPower WECs can further harvest the same AEP from a buoy with 1/10 volume compared to conventional point absorber WEC. By comparison, a 300kW CorPower WEC has a size of 9×18m and weighs 60 tonnes, where other wave devices may have dimensions of 100s’ of meters and several thousand tonnes for the same capacity. Getting large amounts of electricity from a small device significantly reduces CAPEX. The compact lightweight devices are also less costly to transport, install and service, bringing down OPEX.