Can Giant Floating Solar On Oceans Work?

A lot has been said and done about floating solar plants – an emerging technology in which a customised solar photovoltaic (PV) system is placed directly on top of a body of water. Over the past half a decade, floating solar farms have gained popularity, particularly in countries with high population density and competing uses for limited available land. While floating solar has been in vogue for over half a decade now, we made an effort to shed some light on a relatively less talked about Floating Solars on Oceans – Offshore Solar.

Floating Solar – the Next Big Thing

Floating solar has the potential to be the next big thing in clean energy. According to a report on the global floating solar market, the market is expected to grow at a CAGR of 30 per cent and reach a valuation of US$ 27.7 billion by the end of 2031, up from US$ 1.95 billion in 2020.

However, almost all the commissioned projects are built on inland waters, such as lakes and reservoirs.

Why Inland Floating Solar is Preferred?

The inland water bodies are comparatively less tumultuous which is the biggest advantage they have over developing and maintaining floating solar on an ocean surface. Further, material aspects play an important part in longevity.

For instance, steel needs to be protected against corrosion and fatigue damage which is easier in onshore solar due to low salt content. Seawater is normally more corrosive than freshwater because of the higher conductivity and the penetrating power of the chloride ion through surface films on a metal.

Furthermore, accessibility is another major aspect that makes onshore floating solar preferable. Distance and weather dependency make monitoring the operation, inspection and maintenance more difficult for offshore solar PV systems, especially in harsher conditions.

Understandably, the inland water bodies remained a focal point for the development of floating solar panels. However, these water bodies cover less than 2 per cent of the Earth’s surface. One might wonder about the energy that can be harnessed from floating-solar parks if we make use of the vast sea surface potential.

Will Offshore Solar Parks Work?

Floating solar on the ocean surface is the same idea as traditional floating solar on inland waters. It may act as a boon for some of the largest cities located by the sea.

However, there are substantial challenges to building and operating floating solar systems in a harsh maritime realm. For starters, the wave heights are up to 15 m. The floating structures are supposed to stay offshore for a design life of a minimum of 20-25 years and maintenance shall be minimised.

The impact of water and ageing in salty conditions also pose challenges for the development of large solar on the ocean surface. Grid connection challenges must also be considered. A general challenge for offshore floating PV is to achieve a reliable electrical connection between the combiner box and the central inverter, and between the central inverter and the transformer. Furthermore, the longevity of offshore solar is another point to be considered.

Considering all the challenges, it will be prudent to say not all ocean expanses are suitable for the development of floating solar.

Favourable Conditions

The region with the calmest weather, wind and wave conditions possible will be an advantage for the development of offshore floating solar parks. For instance, the Doldrums at the equator. It is a belt around the Earth, near the equator, having little wind and maximum sunlight intensity.

Even offshore wind turbines can get substituted by floating solar if all the other aspects are favourable to the latter. For example, a region receiving equivalent to about 200 watts per square solar radiation will produce over seven times more energy than wind turbines would in covering a similar surface area.

Despite several challenges, various firms have come forward to take on the challenges and open the pandora box full of enormous potential for clean energy.

First-comers in offshore solar

A Chinese company SPIC recently started running what it claims is the world’s first commercial offshore floating solar plant to be integrated with an offshore wind turbine. The pilot project is located off the coast of Haiyang, Shandong province, and uses a patented offshore floating solar technology from Norway-based Ocean Sun. The floating project boasts of an installed capacity of 0.5 megawatts peak and on the success of the pilot, there are plans in the offing to establish a floating wind-solar farm of 20 MW capacity. The firm earlier estimated a capacity of 42 GW of floating solar installations throughout the next few years.

SolarDuck, is a spin-off of Damen Shipyards, is another firm focussing on developing floating solar on the ocean surface. The firm is building the world´s largest Offshore Floating Solar power plant at HKW VII (Netherlands) in partnership with the German energy firm RWE. The project will become operational in 2026. The company is also going to build Japan’s first offshore floating solar demonstrator in Tokyo Bay.

The Solar Energy Research Institute of Singapore (SERIS), Nanyang Technological University (NTU), and Singapore-based developer Keppel Infrastructure also signed an MoU to jointly study the technological and economic feasibility of a hybrid offshore floating solar park paired with the ocean, tidal, and wind capacity. Other names endeavouring the space are  Moss Maritime, Bluewater, Oceans of Energy, and Swimsol.

Last year, Tata Power installed India’s largest floating solar project in Kerala backwaters. Despite challenges such as water depths that kept changing, the strength of sea tides and water salinity problems, the project reached completion within the timeline.

Undoubtedly, establishing projects on ocean surfaces is easier said than done. But there is hope that work on this front has begun already.