Norway-based Ocean Sun AS has revolutionized solar power generation through its patented membrane-based floating solar technology. Ocean Sun recently extended its footprint to India through a collaborative agreement with SJVN Green Energy, a subsidiary of Central PSU SJVN Ltd. In this exclusive interaction, Dr. Børge Bjørneklett, Founder & CEO, Ocean Sun AS, speaks to Venugopal Pillai on this path-breaking membrane technology that has already created very successful references globally. Dr. Bjørneklett is very upbeat on India’s solar potential and strongly feels that this floating solar technology can complement India’s solar power ambitions.
Tell us about the MoU signed with SGEL.
On October 27, 2023, SJVN Green Energy Ltd (SGEL) and Ocean Sun AS signed an MoU envisaging that SGEL shall develop and finance a pilot membrane-based floating solar project of about 2 mw at a suitable location anywhere in India, with patented technological support coming from Ocean Sun AS.
Incidentally, at the Union Ministry of New & Renewable Energy (MNRE), we also signed an MoU with ANERT in Kerala for another demonstration project.
Is the collaboration with SGEL your first project in India?
Yes, this is our very first project in India! We have been, for quite some time, looking at prospective activities in India. But this is the first firm project for Ocean Sun in India.
Have you planned to set up a subsidiary in India, for this project and for those that will follow?
This is very high on the agenda. However, we have not taken a formal decision as yet. If the projects materialize as expected, then we will definitely want to set up a subsidiary here in India.
What is the exact role of Ocean Sun that you would be playing in the SGEL project?
SGEL will be the owner and operator of the solar power plant. Our role will be more on the designing front, and helping out as the technology provider – or as project design architects, if I may say so.
Floating solar is not an altogether new phenomenon in India. How is the technology of Ocean Sun different from what we see conventionally?
Yes, the normal floating solar uses “floats” and we have solar panels on top of each of these floats. However, there are some difficulties with this technology. We believe that membranes are more effective as they entail lower capital expenditure. Membranes are also more efficient as they allow direct and faster cooling of the heated solar panels.
Membranes also have a distinct logistical advantage. Regular floats take up large volume and can be cumbersome in transportation. Membranes, on the other hand, are lighter and can be rolled or compacted into smaller volumes to facilitate transportation.
Do membranes have an advantage when it comes to the nature of the water body on which the floating solar plant would come up?
Yes, floating solar is generally limited to benign waters – with no waves or strong winds. However, Ocean Sun membrane technology allows for installation on coastal areas.
Much of this technology derives from the traditional fish-farming technology of Norway. We have a long and rich experience in understanding the dynamics of natural water bodies!
That is interesting. As we understand, several floating solar plants in India are located on captive water reservoirs of thermal power plants.
Yes, and membrane technology can be safely extended to natural water bodies.
Speaking of the global geographical reach, to which countries has Ocean Sun provided its expertise?
We have done systems in our homeland Norway as well as projects in China. In Philippines and in Albania, we have done projects on hydropower reservoirs. In the planning stages are several projects spread over Singapore, Spain and Greece – to name a few.
We understand the membrane floating solar technology is modular. Tell us more.
Our floating solar projects are mounted on membrane discs. Each disc has typically 0.7 mw worth of solar panels. You can keep adding discs, depending on the intended capacity.
What about the solar panel suppliers? Do you need customized solar modules to suit your patented application?
In India, we are seeking partners for the panels that are traditionally made up of silicon-crystalline solar cells. We are working to secure a full supply chain in India. We use frameless panels fitted with a special attachment feature that engages into the membrane. The junction boxes are also mounted on the sunny side of the panel. The modifications are moderate and can relatively easily be implemented in the manufacturing line. We also prescribe a special water resistant encapsulant for enhanced water ingress protection.
Are owners of the upcoming solar plants involved in selection of solar panel suppliers?
Yes, the owners are very important in the decision-making process for solar panels. Owners also would like to engage with their preferred EPC partners. However, Ocean Sun helps in specifying material quality and technical parameters of solar panels to qualify for this (membrane-based floating solar) application.
What is the typical lifespan of the membrane?
The membrane is tested in accelerated UV (ultraviolet) chamber. It has expected lifetime of 20 years. However, the membranes also can be easily replaced after that period. They have to be because solar panels have a longer life – typically performance warranty of 25-30 years or so. The floating ring at the perimeter of the membrane has a higher lifespan of about 50 years.
Does Ocean Sun actually manufacture the membranes or the supporting frame?
The supporting perimeter is high-density polythene (HDPE PE100) pipe and is easily manufactured. This is the same material that is used in high-pressure water pipes or those used in oil & gas transportation.
The membrane is a technical textile with special composition aimed at high UV resistance and anti-fouling. Coating methodology is also critical. The membrane comes on large rolls from the mills and is subsequently cut and confectioned by thermoplastic welding into the familiar disc shape.
Is your technology patented?
Yes, this is extensively patented around the world. We have more than 110 different patents, globally. At the heart of it, it is the principle of using the membrane.
How do you coordinate the grid-connectivity part of the floating solar plant?
We design the discs with solar panels, as well as the inverters that sit on the perimeter. We also write out single-line diagram to connect these discs, with either a floating transformer or one that is situated onshore. The AC power cables can either be floating or submersible.
Coming back to your Indian projects, when do you expect work to start?
For the SGEL project, our hope is that we can first identify the location for the demonstration facility. This is likely to be near Goa. We plan to start construction, hopefully by next year, in 2024. The survey to select the project site will start soon. The final project will be of around 2 mw, with 3-4 discs involved. We expect that the other initiative with ANERT in Kerala will follow the same progress.
Would Ocean Sun be involved in the project site selection survey?
Yes, we will study the metrological data and also the topology (bathymetry) of the seabed. We will then dimension the entire structure and mooring as a function of three vital environmental load parameters – wind, wave and current.
After site finalization and arrival of equipment, what is the typical gestation period of a membrane-based floating solar power plant?
For demonstration, we will spend some time in training to the installation crew. However, it is technically possible to commission these discs at very high speed. We can even do one disc per day in a high-volume setup!
Globally, what is your largest project so far?
It is 2-mw; we did that for power utility Statkraft in Albania.
Speaking of floating solar, India is also using such solar plants to mitigate water evaporation from irrigation canals. Do you see this as a use-case for Ocean Sun?
Yes, this can be a very good application! However, in such projects, the discs will be smaller so as to fit the width of the canal. Membrane-based floating solar can be much cheaper than conventional solar over canals as the capital expenditure of building steel structures across the span of the river or canal is avoided.
India has very ambitious renewable energy goals. Given this, how do you see India as a potential market for Ocean Sun?
Yes, I am extremely positive on India’s solar potential. I think floating solar can contribute to electrification on a grand scale. Solar power can help not only in electrification but also contribute towards improving air quality and standard of living.
Note: All project photographs in this interview relate to projects commissioned by Ocean Sun AS for its clients, globally. More information on Ocean Sun’s project portfolio may be found here.
