Floating Solar On Sea- How Close Are We ?

How do you supply electricity to 10,000 islands? Indonesia has over a million people who don’t have access to electricity. Floating solar aims to remedy cases like these.

Proposed as a solution to the issue of land use and the issue of not being able to adopt expensive solutions like wind turbines in certain coastal areas, floating solar offers some unique advantages.

For one, floating solar is very convenient because it can just be put on top of the water. If more electricity is needed, you can just add more solar panels according to Luofeng Huang, a lecturer in mechanical engineering at Cranfield University.

Additionally, the proximity to water is in fact beneficial for solar panels. Solar panels typically operate at peak efficiency between 15C and 35C. Floating solar being near water means that panels operate more efficiently compared to traditional solar, with an efficiency bump of up to 15%. Floating solar panels can also create shade and reduce water temperatures, potentially conserving an estimated 106 cubic kilometers of water per year.

Floating Solar- Spreading Fast

From the Brazilian Amazon to Japan, floating solar panels are booming around the world. Floating solar capacity has grown from 70 mWp in 2015 to 1300 mWp in 2020, to almost 5 GW currently, floating solar is on a tearing growth path. The annual floating solar additions are expected to top 6 GW per annum by 2031, according to WoodMac. There is huge potential to merge floating solar with existing renewable technologies like hydropower or wind power. You could have a truly reliable renewable energy source, with each source picking up the slack if the other goes down.

Located in the Ubon Ratchathani province about 660 kilometers east of Bangkok, Thailand lies the Sirindhorn Hydro-Floating  Solar Hybrid Project which combines the capacities of a 45 megawatt floating solar farm with the Sirindhorn Dam which has an equivalent generation capacity. The farm generated electricity from solar power during the day while the dam provides power when there is no sunlight. This endeavor has reduced greenhouse gas emission by about 47000 tons per year.

What About Floating Solar At Sea?

While the technology has seen some amount of adoption, it’s mostly in lakes and reservoirs and not at sea, the reason behind which being the fear of waves swamping and damaging solar panels. In fact, most of the current estimates of floating solar are based on global reservoirs, not floating solar at sea.  Even though organisations like DNV have projected upto 1 GW of floating solar in places like the North Sea by 2031, counting on technology enhancements and dropping prices.

Most Research and testing is under way to make solar panels more sturdy and keep them operational in rough water, to varying degrees of success.

Dutch-Norwegian company SolarDuck looks to build a floating solar plant at a North Sea wind farm, utilizing platforms raised several metres above the ocean surface. Due to be operational in 2026, the plant will make use of existing cabling for the wind farm to send electricity back to the shore.

Norway-based company OceanSun has developed a floating rig, where the solar panels rest on a base which flexes as the waves pass underneath, not dissimilar to how suspension works. By preventing the breakage of waves, the technology prevents most of the kinetic energy from affecting the solar panels.

Both startups are looking at floating solar farms next to traditional wind farms, hoping to smoothen the flow of electricity when the wind isn’t blowing.

Countries like Singapore in Japan are investing heavily in floating solar technology due to their limited land resource availability. Countries in Africa could stand to benefit from floating solar panels as well. Solar panels floating on just 1% of Africa’s hydropower reservoirs could double the continent’s hydropower capacity and increase electricity generation from dams by 58%. Utilizing the ocean surface outside Singapore might be the only way to provide affordable renewable energy in the island-country.

Floating solar has seen its fair share of innovation, best demonstrated by the Proteus project.

Named after the Greek Sea God Poseidon’s retainer and developed by SolarisFloat, the European Inventor Award finalist project makes use of double-sided panels that track the sun and tilt to follow it throughout the day, similar to the way young sunflowers follow the sun from east to west during the day. According to research by SERIS, tracking technology could boost energy production by 35% and reduce the average cost of electricity by 16% compared to conventional systems. The system floating in Oostvoornse Meer, a lake in the south west Netherlands, has a total installed capacity of 73kWp.

According to Thomas Reindl, deputy chief executive of the Solar Energy Research Institute of Singapore (SERIS), covering just 10% of all man-made reservoirs in the world with floating solar would result in an installed capacity of 20 terawatts:- 20 times more than the global solar PV capacity today.

While hydro-floating photovoltaic projects are costly endeavors, large scale deployments and technological advancements will drive down costs, bringing it down the same path as traditional solar, which has recently been crowned the world’s cheapest source of power.

 

 

By Yash Singh