Explained | What are Floating Solar Farms and how they can help fight Climate Change

With the growing demand for solar energy, solar plants or farms are being increasingly installed across the globe. This has led to a shortage of land for large-scale solar plants, especially, in the over-populated regions of the world like Asia. To counter the constraint of land, an ‘alternative’ has emerged in the form of floating solar plants or farms installed on water bodies. Floating solar farms are the latest development in terms of renewable energy technology. They are increasingly being regarded as a game changer to help achieve global net zero targets. Experts say that floating solar farms can put an end to the global energy crisis and reduce emissions at the same time, thus helping fight climate change.

What exactly are Floating Solar Farms?

Floating solar farms are solar panels installed on the surface of lakes, reservoirs, or near coastal areas. They were also known as floating photovoltaic (PV) systems, or floatovoltaics. Floating solar farms consist of solar panels fixed on buoyant bodies made of polyethylene, keeping them afloat on the water surface. The electricity is sent from this floating structure through underwater cables to a transmission tower. It is an eco-friendly method of producing electricity and combines marine and renewable energy technology. 

Generally, a floating solar farm is like a normal solar farm on land but in this case, it is floating on water. The floating solar power plant comprises ‘the solar module, buoyancy body, and anti-rust material, which includes the vertical frame and horizontal frames, inspection footrest, and module mount assembly’.

Worldwide popularity

Floating solar farms are increasingly being built in growing numbers across the world. The 320-megawatt Dezhou Dingzhuang Floating Solar Farm in China’s Shandong province is one of the world’s biggest floating solar farms and can be seen from space. NASA had clicked photographs of this floating solar farm which were widely shared on social media. 

The Healdsburg Floating Solar Farm located in California is the biggest floating solar project in the United States. It has 11,600 solar panels and can generate 4.8 megawatts of electricity which is enough to meet 8% of the electricity needs of Healdsburg. In Singapore, the mammoth floating solar farm on the Tengeh Reservoir is equal to the size of 45 football fields and consists of 122,000 floating solar panels. 

What do the experts say?

According to NASA, ‘as countries look to decarbonize their economies, floating solar farms have become an option’. A study titled, ‘Floating solar power could help fight climate change — let’s get it right’ published in Nature calculated that if we cover 10% of the world’s hydropower reservoirs with floating solar panels, we could have enough electricity to compensate the current electricity produced by all the world’s fossil fuel power plants. 

Advantages of Floating Solar Farms

1. Not losing valuable land space

This has to be the most significant advantage of floating solar farms, especially in countries or regions where because of high population density there are constraints on land availability. Since ground-mounted solar panels eat up significant land space, floating solar farms become a viable alternative to be installed on unused space on water bodies such as wastewater treatment plants, drinking water reservoirs, or hydroelectric dam reservoirs. 

2. Environment benefits 

Negative impacts like deforestation associated with land-based solar power projects are absent in the case of floating solar farms. Also, floating solar panels reduce evaporation from water bodies which is a positive effect in areas prone to droughts. The solar panels also reduce the blooming of algae in water bodies. 

3. Improved performance

Solar panels can perform well under high temperatures but over time as the temperature increases, their efficiency also reduces. Water provides a cooling effect for the photovoltaic modules in the case of floating solar panels which improves their efficiency. 

4. Simpler installation and decommissioning 

Floating solar plants are compact in comparison to land-based plants and their installation as well as decommissioning are simpler and straightforward. Since there is no fixed structure involved, they are easy to set up as well as move from one place to another. 

5. Tracking

Floating solar platforms can be easily rotated horizontally and vertically to enable sun-tracking but in the case of land-based photovoltaic plants complex mechanisms are needed. Significant energy gain can be achieved by equipping a floating photovoltaic plant with a tracking system at a minimum cost. 

Disadvantages of Floating Solar Farms

1. Expensive to Install

At present, installing a floating solar panel is costlier than the traditional land-based photovoltaic system. This, of course, is because the technology is relatively new and requires specialized equipment and knowledge. 

2. Long-term reliability 

Installation on water requires the components of the system to have enhanced corrosion resistance and long-term floatation capabilities, especially in the case of installation over salt water. 

3. Application limitation

This might not be suitable for everyone and for many, choosing rooftop installation or ground-mounted solar might be more practical. Floating solar plants are generally large-scale, catering to large communities or companies.

4. Maintenance complexity

Maintenance activities are, generally, more difficult to perform on the water than on land. Also, needs to withstand relatively higher winds than on land and heavy waves in case of off-shore or near-shore installations.

Floating Solar Farms in India

Indi’s largest floating Solar Power Project is now fully operational as NTPC recently declared the beginning of commercial operation of the final part capacity of 20 MW out of 100 MW Ramagundam Floating Solar PV Project at Ramagundam, Telangana with effect from July 01, 2022. 

With the operationalization of 100-MW Solar PV Project at Ramagundam, the total commercial operation of Floating Solar Capacity in Southern Region rose to 217 MW. Earlier, NTPC declared commercial operation of 92 MW Floating Solar at Kayamkulam (Kerala) and 25 MW Floating Solar at Simhadri (Andhra Pradesh). 

In addition to the above, multiple mammoth-size floating solar farms are being built or are at different stages of commission in India. A 600-megawatt floating solar energy plant is being built at the Omkareshwar Dam on the Narmada river in the state of Madhya Pradesh. Another 1-gigawatt floating solar power project is reportedly planned at the Indira Sagar dam in Madhya Pradesh. Multiple other small and medium-sized floating solar farms are being planned by various state governments as well as private companies across the country. 

The 100-MW Floating Solar project at Ramagundam

The 100-MW Floating Solar project at Ramagundam is divided into 40 blocks, each having 2.5 MW.  Each block consists of one floating platform and an array of 11,200 solar modules. The floating platform consists of one Inverter, Transformer, and an HT breaker. The solar modules are placed on floaters manufactured with HDPE (High-Density Polyethylene) material.

The entire floating system is anchored through a special HMPE (High Modulus Polyethylene) rope to the dead weights placed in the balancing reservoir bed. The power is being evacuated up to the existing switch yard through 33KV underground cables.  This project is unique in the sense that all the electrical equipment including inverter, transformer, HT panel and SCADA (supervisory control and data acquisition) are also on floating ferro cement platforms. The anchoring of this system is bottom anchoring through dead-weight concrete blocks.