Floating Solar Farms: Renewable Energy Production and Seaweed Cultivation Join Forces at Sea

by | Oct 16, 2021 | Blog

Seaweed growing under the sea with rays of light from shining through the surface.


  • Two Dutch companies have been working together to create the first combined offshore seaweed and solar farm, located 12km off the coast of Scheveningen—a district of The Hague.
  • Since 2019, the floating solar system has been generating clean energy and has managed to withstand the sea climate, including surviving waves up to 4 metres during two major storms called Ciara and Dennis in the winter of 2019.
  • Successful seaweed cultivation is also an enormous business potential for the Netherlands as high-quality seaweed production is a lucrative market and used for more than food.
  • Additional research is being conducted on a floating solar farm located further off the coast with solar panels able to withstand up to 13-metre waves. This shows the potential for floating solar farms to be installed between offshore wind turbines—resulting in the Netherlands only needing to allocate 5% of the Dutch North Sea to generate half of their nation’s energy demand.


Solar power is a fantastic source of renewable energy. Solar technologies can convert sunlight into electrical energy using photovoltaic (PV) panels or mirrors that concentrate solar radiation. The power can then be used to generate electricity or be stored in batteries or thermal storage.

Solar scientists are now going a step further in using solar technology to help support food production. A seaweed company and an offshore solar energy system developer have been working together to create a combined seaweed and solar farm in the North Sea. This is the first time any such project has taken place.

The companies are Oceans of Energy and The Seaweed Company, and both happen to be Dutch. They are partners in the UNITED project—an EU-funded programme promoting the improved sustainable and efficient use of ocean resources. The combined offshore seaweed and solar farm are located 12km off the coast of Scheveningen, a district of The Hague.

Together, the project partners demonstrate the potential of cultivating seaweed for its many uses while generating clean energy. So let’s take a closer look and learn a bit more about offshore solar farms and seaweed cultivation.

The Potentials of Seaweed

In the 20th century, the emphasis has shifted from using the whole seaweed to identifying the benefits of different molecules they contain.

Since ancient times, seaweed has been used for various uses, including food, medicines, fertilizers and animal feed. In the 20th century, the emphasis shifted from using the whole seaweed to identifying the benefits of different molecules they contain.

Seaweed is more prevalent in our daily lives than might be initially thought. Here are some of the examples of everyday seaweed use:

  • Food
    Seaweed is a popular ingredient in Asian dishes. The Food and Agriculture Organization of the United Nations has reported that since 1973, around 654,000 tons of wet weight seaweed have been eaten each year in Japan. Western cuisine incorporates seaweed as a thickening agent. For example, carrageenan—a red seaweed extract—is added to puddings, jams, jellies, chocolate milk, and chewing gum. Algin—from brown seaweed—and agar —from red seaweed—are widely used in bakery products, sweets, dairy products, salad dressings, ice cream, creams and jellies. It is also used in processing meats, sausages, and fish and in clarifying wines and beers.
  • Pharmaceuticals
    Algins and carrageenan are used in pharmaceuticals as binders, stabilizers, emulsifiers and for creating moulds. For example, the dental industry uses them during teeth moulding preparations. It has also been found that algins provide a controlled release to solid oral medications, gastric reflux control, thickening and stabilization to oral liquids—like cough medicine—and are used in wound care.
  • Science
    Agar—obtained from the cell walls of some red algae—has been a backbone of bacteriological investigations since 1900. Bacteria are laid onto agar preparations in Petri dishes or test tubes, making it possible to study their culture
  • Cosmetics
    In mainstream cosmetics, carrageenans are used in skin cleansers, toothpaste, shampoos, hair conditioners and shaving products. Some brands also crush seaweed or make a seaweed paste and add it to a large variety of products, such as facial masks, body gels, creams and shampoos. Alginates are also added to various cosmetics.
  • Fertilizers
    Seaweed has been found to work as a fantastic fertilizer as it adds trace elements and plant nutrients such as phosphorus, potassium, and nitrogen. In addition, when seaweed is used whole or dried, it adds organic matter to the soil. There are now fertilizer companies that prepare the seaweed, so it is dried and ground into a fertilizer meal or processed into seaweed extract before being diluted for use.
  • Industrial Products
    Algins appear in all sorts of industrial products, including dyes, paints, pigments, and other finishes. They are also used in fibre manufacturing to make paper, cardboard, filters and textiles. In addition, charcoal briquettes are bound together with seaweed. More surprisingly, algins are also used in manufacturing explosives, pesticides and fire retardants such as fire extinguishers.

Seaweed may also soon be used as a biofuel due to its high water content. Between 85% and 90% of seaweed is water, which makes seaweed suitable for biofuel-making methods like anaerobic digestion to make biogas and fermentation to produce ethanol. In addition, seaweed does not need freshwater or fertilizing.

Floating Solar Panels At Sea

Recent studies have indicated that solar systems on water generate more electricity compared to rooftop or ground-mounted solar panels.

Graphic of solar PV panels floating on a body of water.

Although electricity and water do not usually mix, floating solar farms have been installed across bodies of water such as reservoirs and lakes for years. Recent studies indicate that solar systems on water generate more electricity compared to rooftop or ground-mounted solar panels. This is due to the water providing a cooling effect beneath the panels. The water can boost the efficiency levels of the power generation by as much as 12.5%.

Floating solar farms have now arrived in the North Sea just off the Dutch coast. In 2019 Oceans of Energy installed the system which generates clean energy, can withstand the sea climate and has survived waves up to 4 metres during storms such as Ciara and Dennis in the winter of 2019.

Following the 2019 storms, the team is testing solar panels under even more challenging conditions. There is now a second site located further offshore, built to withstand up to 13-metre waves. This shows that solar farms can be installed alongside offshore wind turbines. The systems could create 100 to 5000 MW of offshore solar energy per project by creating solar and wind hybrid projects.

Having experimented with the first-ever offshore solar system on the North Sea, Oceans of Energy and The Seaweed Company have managed to combine food production with generating clean energy—two fundamental needs. However, as mentioned in the above section, seaweed can be used for much more than food. Financial market analysis indicates that the global seaweed market is growing and will be worth around $92 billion by 2025.

Seaweed cultivation could be a lucrative export for the Netherlands over the coming years. There is enormous business potential in high-quality seaweed production, and combining seaweed cultivation with renewable energy could reduce costs and increase efficiency. In addition, for the Netherlands, by installing offshore solar systems using the space between the wind turbines, they would only need to use 5% of the Dutch North Sea to generate half of their nation’s energy demand.

The UNITED project is also running pilot demo sites in Germany, Belgium, Denmark and Greece to test further potentials of offshore solar farms and food production. These additional four pilots are testing blue mussel aquaculture, fish aquaculture, and flat oyster aquaculture and restoration.

Closing Thoughts

Floating solar installations are advancing, and we see various designs being tested in various marine environments. The potential of clean energy production and supporting food cultivation is an exciting concept, but more research is still needed before widespread installations can commence.

It is clear that research into understanding the environmental and societal implications of floating solar in the marine environment must progress in parallel with technical and economic practicability investigations. The long-term effects of floating solar panels on the marine environment are unknown as little can be learned from floating solar panels on freshwater, as it is a very different environment. On a positive note, the impacts of floating solar power systems on freshwater habitats have been promising.

Frequently Asked Questions (FAQs)

What is a floating solar farm?

A floating solar farm—sometimes called floatovoltaics—is a solar panel mounted onto a structure that floats on a large body of water. Floating solar farms are typically installed on lakes, reservoirs, and artificial basins. However, floatovoltaic technology is now leaping forward as testing sites are being installed out at sea.


Why invest in floating solar PV?

The World Bank forecasts an explosion of floating solar projects over the next two decades—going so far as to report that floating solar offers significant opportunities for the global expansion of solar energy capacity. For green investors interested in solar technological advancements, floating solar could be one to watch.


Which countries are implementing offshore solar farms in their seas?

There are currently over 60 countries actively pursuing the development of floating solar farms. Although the projects are relatively new compared to their land-bound counterparts, there are estimated to be around 350 operational FSPV systems, producing a total of 2.6 GW of renewable energy.


Where is the world’s largest floating solar farm?

The world’s largest floating solar farm will be on the island of Batam in Indonesia. It is installed on an area of ​​1,600 hectares and has an expected output of 2.2 GW. It will also have the most extensive energy storage system (ESS) with a storage capacity of over 4000 MW. Construction is due to start in 2022 and be completed in 2024.


Could floating solar farms protect natural waters against global warming?

Floating solar farms on lakes have a considerable impact on the water temperature. Depending on the design, a floating solar farm can potentially reduce wind speed and solar radiation by 10% across an entire lake and offset a decade of warming from climate change.