The story so far: India’s largest floating solar power project, spanning over 600 acres, is now fully operational at Ramagundam in Peddapalli district of Telangana. The 100-megawatt (MW) project formally went on stream after the state-run National Thermal Power Corporation (NTPC) declared that the last 20 MW capacity part was ready for commercial operation on July 1.
In recent years, floating solar power plants have become part of India’s plans to achieve a national target of 100 GW solar capacity by 2022. According to a 2020 study by think tank The Energy and Resources Institute (TERI), reservoirs cover 18,000 square kilometres in India and can generate 280 GW through floating solar panels.
What is a floating solar plant and how does it work?
A network of floating solar panels, or photovoltaics/floatovoltaics aremounted on a structure that is made to float on the surface of a water body, which could be a reservoir, lake, irrigation canal, or pond.Usually, a floating solar plant will have a floating system or pontoon, a mooring structure to prevent panels from moving freely in water and to keep it near the shore, a photovoltaic system to generate electricity using thermal energy, and an underwater cable to transfer the generated power to a substation.
Representation of a typical floating solar plant.
Rise of the floating solar power technology
More and more countries are switching to eco-friendly methods of producing electricity to make their energy portfolio cleaner and greener to tackle climate change. Power generation technology using floating solar panels has proved to be an efficient and fast-growing approach toward clean energy, especially in countries where land is scarce.
The first floating photovoltaic system was built in Japan in 2007. Several countries like the U.S, France, Italy and Spain followed, but the use was limited to research and demonstration. In 2008, the first commercial installation, though small in size, came up in California after which renewable technology was quickly adopted by other countries. According to a World Bank Group report, floating solar capacity grew from 70 MW of peak power in 2015 to 1,300 MW in 2018. As of 2020, there were more than 300 floating solar installations worldwide. Global research firm Wood Mackenzie has estimated that global demand for floating solar power will grow by 22 per cent year-over-year on an average from 2019 through 2024.
As per another article, published by the World Economic Forum in 2021, floating solar power grew more than a hundredfold in five years, reaching 2.6 gigawatts of installed capacity across 35 countries. “If just 1 per cent of the surface area of all human-made water bodies (which are easier to access and typically less ecologically sensitive than natural lakes) was covered by floating solar panels, it could generate 400 gigawatts – enough electricity to power 44 billion LED light bulbs for a year,” the article adds.
Currently, the world’s largest floating solar farm is in Shandong, China. The plant generates 320 MW per hour. Interestingly, China has turned collapsed coal mines into an opportunity by setting up floating solar farms in flooded areas. In 2021, Singapore unveiled a floating solar panel farm, spanning an area equivalent to 45 football fields. South Korea plans to build a massive floating solar farm in the province of North Jeolla. Its capacity, expected to be 1,200 MW, will be equivalent to about 0.9 per cent of the total capacity of the country’s electricity generation.
Floating solar panels near Hapcheon Dam in South Korea. | Photo Credit: (South Korean Govt)
How India is switching to floating solar projects
India launched the National Solar Mission in 2010 to tap sources of renewable energy. According to a study done by TERI in association with the Energy Transmission Commission India programme, 2.7 MW capacity floatovoltaic projects were in operation as of 2019, while over 1.7 GW were in various stages of development. The Government plans to establish a renewable energy capacity of 500 GW by 2030.
The NTPC, with a target to produce 60 GW capacity through renewable sources by 2032, said italready commissioned 222 MW of floating solar projects, with another 40 MW in the construction stage. So far, the NTPC has installed floating solar plants on reservoirs at Kayamkulam in Kerala (92 MW) and Simhadri in Andhra Pradesh (25 MW). The world’s largest floating 600 MW solar energy project is being constructed on the Omkareshwar dam in the Khandwa district of Madhya Pradesh, covering approximately 2000 hectares. Projects at Getalsud in Jharkhand, Rihand reservoir in UP, and Vaitarna in Maharashtra have also been cleared.
Floating power plants laid over two artificial lakes located in the CIAL golf course in Kerala. (File photo)
The project in Ramagundam, Telangana is the country’s largest floating solar power project. Built at a cost of Rs. 423 crore, the project is spread over 600 acres of the NTPC reservoir in Ramagundam.
The 100-MW project uses advanced technology and environment-friendly features and was built through BHEL under aEPC (Engineering, Procurement and Construction) contract, according to a statement by the Ministry of Power. The floating solar project has been divided into 40 blocks, each having a capacity of 2.5 MW. Each block consists of one floating platform and an array of 11,200 solar modules. The solar modules have been placed on floaters manufactured with High Density Polyethylene (HDPE) material. According to the official statement, the project is unique since all the electrical equipment is on floating ferro-cement platforms, with deadweight concrete blocks acting as anchors.The NTPC has claimed that the 100MW project will save 2000 million litres of water per annum, sufficient to meet the yearly water requirements of approximately 10,000 households.
With the operationalisation of 100-MW Solar PV Project at Ramagundam, the total commercial operation of floating solar capacity in the NTPC Southern Region has risen to 217 MW. (Credit:NTPC)
The Ministry of Power has said that approximately 32.5 lakh cubic meters per year of water evaporation can be avoided at Ramagundam. “The water body underneath the solar modules helps in maintaining their ambient temperature, thereby improving their efficiency and generation. Similarly, while coal consumption of 1,65,000 tons can be avoided per year; CO2 emission of 2,10,000 tons per year can be avoided,” the Ministry has added.
Are floating solar panel farms more efficient?
Solar power is the cheapest electricity in history, as per an International Energy Agency (IEA) report. Besides constraints pertaining to land, scientists feel that ground-mounted solar panels are unable to function at their full potential as they heat up. This is where the floating solar technology has an edge even though such farms are comparatively more expensive. Some advantages of floating solar power projects include:
Less use of land: Installation of solar panels on land or rooftops increases land pressure. For countries where the population density is high and land sparse, ground-mounted panels are not favourable. On the other hand, floating solar farms don’t need land for installation. A solar farm can be set up on the surface of a water body which is otherwise not being utilised.
Higher efficiency: Like any other electrical equipment, solar panels operate more efficiently when kept cold. According to the Environmental and Energy Study Institute, floating solar farms can be up to 15 per cent more efficient than those on the ground due to the cooling effect of the water beneath panels. As a coolant, water maintains the temperature of solar panels which eventually prevents loss of energy due to higher temperatures. Also, since they are deployed on the water surface, it is convenient to clean and move the network in the direction of sunlight.
Better for the environment: Floating solar farms, if designed and deployed appropriately, reduce the threat posed by climate change to water bodies. Floating panels can offset climate change by 10 years, according to the WEF report. “Our results suggest that the changes to water temperatures caused by floating solar farms could be as big as climate change itself, only in the opposite direction,” the 2020 report says. “A floating solar farm that reduces wind speed and solar radiation by 10 per cent across the entire lake could offset a decade of warming from climate change. Designs that shaded the lake more than sheltered it, by reducing sunlight more than wind, had the greatest cooling effect. Evaporation fell and the lake was mixed more frequently, which helps oxygenate the deeper water,” it reads. Also, solar panels prevent the growth of algae in the water, which improves its quality.
There are, however, a few challenges too. Since the technology is relatively new, experts are worried about the long-term ecological impact on water ecosystems. Solar panels can block sunlight, which can affect aquatic life, experts say.
TheWorld Bank notes some of these challenges in its report ‘Where Sun Meets Water’ — “...the lack of a robust track record; uncertainty surrounding costs; uncertainty about predicting environmental impact; and the technical complexity of designing, building, and operating on and in water (especially electrical safety, anchoring and mooring issues, and operation and maintenance).”
The Gist
- India’s largest floating solar power project, spanning over 600 acres, is now fully operational at Ramagundam in Peddapalli district of Telangana
- In recent years, floating solar power plants have become part of India’s plans to achieve a national target of 100 GW solar capacity by 2022
- The NTPC has claimed that the 100 MW project will save 2,000 million litres of water per annum, sufficient to meet the yearly water requirements of approximately 10,000 households
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