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Navigating the Waves of Progress: Kim Nielsen's contributions to wave energy development

Bijgewerkt op: 19 jul. 2023

In the realm of renewable energy, wave energy has emerged as a promising yet challenging frontier. Kim Nielsen, a wave energy consultant from Denmark, has dedicated over four decades to researching and developing wave energy systems. Currently working part-time at Ramboll, an engineering company, and Aalborg University, while also running his own company, Development by Kim Nielsen. His primary focus is advancing ocean wave energy solutions.

Kim Nielsen testing a mooring system

Kim Nielsen, in an interview with Sia Windig for EWA, sheds light on his journey in wave energy research and development and discusses the current state of the industry. He reveals his pioneering work on integrating oscillating water columns into ship structures and highlights the requirements for a thriving marine energy industry. Is there a Dutch perspective on wave energy? As a Dane living in Amsterdam, he has the answer. Nielsen's extensive experience spans over four decades, making him a valuable voice in the field.


What are your current projects for wave energy?

Oscillating water columns within a ship structure

Currently, I am working on integrating oscillating water columns into a ship structure. I learned about this idea during the first Wave Energy Symposium in Gothenburg in 1979. At that time I had been granted a Ph.D. study at DTU (Danish Technical University) on “boundary layer around ships”. However, after attending the symposium and learning about all the fascinating ideas for wave energy conversion I asked if I could change the subject to Wave Power Converters. In 2013 I decided to investigate why for so many years I had not heard more about what was called the I Beam Attenuator. Collaborating with students from DTU, we are now actively investigating the integration of oscillating water columns within the ship structure. The idea is to harness the motion of the waves through these water columns, generating energy on board the ship while also exploring possibilities for hydrogen production.

The KNSwing a shiplike structure including oscillating water columns on each side of the hull.
The KNSwing a shiplike structure with oscillating water columns on both sides of the hull.

How do the oscillating water columns work?

Oscillating water columns utilize the rise and fall of water levels caused by wave action. As waves enter a partially submerged chamber, the rising water column displaces air, which drives a turbine connected to a generator. When the waves recede, the falling water column draws air back into the chamber, generating another cycle of energy production. This continuous motion of rising and falling water levels drives the turbine, converting wave energy into electrical power.

In which stage of development is your project?

The project is currently underway in my personal company, "Development by Kim Nielsen." From 2020 to 2023, it has been evaluated and supported as part of the Marine Energy Alliance (MEA) project. I received a so-called Technical Performance Level (TPL) assessment which provides a measure of techno-economic performance potential. The assessment confirmed that the project was on the right path with a TPL score of 7.2 (on a scale of 1 to 9) at TRL 3-4. The next steps are to optimize the structural design and geometry of the chambers, evaluate the lifetime of mooring lines, and evaluate the water impact on the ceiling of the air chambers.

The TPL methodology has been developed as part of a project WaveSPRACK lead by Sandia and co-ordinated by NREL in US a project that I have been involved in since 2015 as part of my Ramboll employment.


What triggered your journey into wave energy?

It began during the energy crisis in the seventies when Denmark faced restrictions on driving cars on Sundays. I had just past my driving test and was keen to drive. I started wondering about alternative sources of energy independent of oil.

Carless Sundays can be inspring

I studied at the Department of Ocean Engineering at DTU. One day we had a lecture on water turbines in a course on hydraulics. We were taught that water turbines could produce power proportional to the flow times of the height of the waterfall. I thought it was a pity that Denmark, like the Netherlands, is flat and without any waterfalls. But during the night, I woke up with a vision of a water head equal to the water depth over the seabed. I made a few drawings of wave pumps and did some simple calculations on how much power could be generated.

I initially intended to design a sailing boat. When I shared my wave energy idea with my teacher he encouraged me to go for that. So thanks to my teacher I delved into the development of wave converters. Over the next four decades, I immersed myself in the field. I attended the first conference in Sweden in 79, which was for me sort of an eye opener on how many ideas there were. All these researchers working worldwide on getting energy out of the waves.

What steps can be taken to accelerate the development and commercialization of ocean energy technologies and make it a mature and financially viable industry?

In comparison, in offshore wind energy, a great convergence has taken place. In the beginning, there were many different concepts, but they all agreed to go after three blades and then work from there. So now one wind turbine looks very much like the next, at least superficially. At the same time, wind power has seen a dramatic drop in price per kilowatt-hour and growth in investments. Wave energy, on the other hand, is still very much in the prototype and demo phase and investments lag behind.

I believe it would help to focus on one or two specific projects and then build from there, exploring how it could work in combination with wind and other established technologies. The wave energy community needs to make a choice and rally around one or two flagship projects, consolidating resources and attracting investors. Beyond testing and small tryouts, a more substantial and coordinated effort is required to drive the industry forward.

Just like in wind energy convergence could help the marine energy industry forward

Who should take the lead in implementing this new strategy?

To effectively implement the wave energy strategy and maximize its potential, a collective effort is needed, spearheaded by political will and collaboration among various stakeholders. In this regard, it is essential for politicians to receive crucial information from wave energy associations, including those from the Netherlands, Denmark, and Europe as a whole. These associations can play a pivotal role in offering technical and economic assessments using standardized methodologies.

By adopting similar evaluation criteria, these associations can provide a comprehensive and unbiased overview of the wave energy converter (WEC) technologies available, akin to a sailing regatta. This approach ensures fairness and transparency in determining which WEC technology leads the way, following established rules and regulations.

If you look back on the past decade, are there significant moments which helped the development of wave energy forward?

Definitely, I can name two.

1. Grassroots development program by the Danish government

Wave Rotor (photo: Peter Scheijgrond, 2002)

In Denmark, around the year 2000, there was a political initiative to support wave energy specifically. The Danish government established a grassroots development program in the late 1990s, offering financial support to inventors with plausible ideas to harvest wave energy. This resulted in a series of prototypes such as Wave Dragon, Floating Power Plant, Wave Plane. Also the Wave Rotor, developed by Peter Scheijgrond (Bluespring) and Danish inventor Eric Rossen received support through this program. Support from governments can give such a boost. It really helped! But unfortunately, that program ended because we got a new government in Denmark that wanted to do things differently from the previous government.

2. International Energy Agency task on Ocean Energy Systems (IEA-OES)

A second initiative is the International Energy Agency collaboration on Ocean Energy System (IEA-OES) between countries. Denmark and Netherlands are both participating. It is helpful because the intention is that we share development on what's going on and we align on effective policies. It is a great platform where the voice of wave energy is really being heard. I like to combine my Dutch and Danish knowledge there.

As a Dane living in the Netherlands do you see a Dutch perspective on wave energy?

Well, when it comes to the Dutch energy landscape, I must say they impress me with their efficiency and openness to exploring new ways of combining renewable energy technologies. That's actually why I joined the Dutch Energy from Water Association (EWA). It's a great opportunity for me to stay updated on the developments happening in the Netherlands, and it's a nice community to be a part of.

What I've noticed is that the Netherlands has a different approach to doing things, and they tend to be quite efficient. Recently a fascinating assessment was conducted by TNO, a Dutch research organization, full-scale to explore the synergies between offshore wind and wave energy. TNO studied how these two sources can work together to achieve more consistent energy production throughout the year. It's an exciting prospect that highlights the potential of integrating wave energy with other renewables.

I believe it's crucial to further explore this integration to maximize the contribution of wave energy to the overall energy mix. By combining different renewable sources, we can enhance the sustainability and reliability of our energy systems. The Dutch perspective on wave energy emphasizes this collaborative and innovative approach. I find that truly inspiring.

An energy crisis piqued your interest in wave energy. Here we are 50 years later with a new energy crisis. Have you kept the faith that wave energy will have a significant impact in the field of innovative offshore renewable energy solutions?

I do have faith that it will have a great impact in the future. But I must confess I'm surprised that it takes so long. I keep emphasizing the importance of convergence and focused efforts. It is crucial. There are some promising initiatives already taking place, like CorPower Ocean's project in Portugal that will demonstrate their full-scale wave energy converter in Atlantic wave conditions. Such collaborative efforts and international collaborations, like the work done by the International Energy Agency, contribute to knowledge sharing and pave the way for – at last! - a sustainable future for wave energy.

EMEC, Orkney, Wave Energy
Stephen Salter and Kim on the rocks of the Orkney 10 years before EMEC started operating its open water test facilities. Photo by Peter Randløv in 1992

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