Floating solar takes off

The Cabinet recently approved the Pradhan Mantri Surya Sarovar Yojana (PM-SSY) for the development of floating solar photovoltaic projects with energy storage systems, with a total outlay of R5,070 crore. This is indeed a laudable initiative. Globally, the floating solar panel industry is relatively new and is estimated to be worth about $53 billion. It is growing rapidly at a CAGR of around 25 per cent and is expected to increase fivefold by 2033. The Asia-Pacific region is witnessing particularly strong growth, led by India, China and Japan. Incidentally, Japan was the first country to introduce floating solar projects.

India is a relatively new entrant, with a few projects already operational. Many more are planned and are expected to come up over the next few years on canals and other man-made water bodies.

The scheme envisages the development of 5,000 MW of floating solar photovoltaic projects with co-located energy storage systems having a minimum storage capacity of two hours, or 10,000 MWh. The projects will be sanctioned between FY26-27-FY30-31, with financial assistance continuing until FY32-33.

Under the scheme, Central Financial Assistance (CFA) of R1 crore per MW will be provided for eligible floating solar photovoltaic projects after successful commissioning. In addition, CFA of up to R50 lakh per project will be available for feasibility studies, including those required to de-risk the projects.

One of the key factors driving the adoption of floating solar photovoltaic panels is the opportunity cost of land, which can often be put to more productive use for agriculture or industry. Even in countries with large tracts of unused land, ground-mounted solar projects may be less efficient because of the costs involved in transmitting electricity across the grid to population centres.

Most floating solar projects are installed on man-made lakes, canals, reservoirs, catchment areas and hydropower dams, particularly at higher elevations where uninterrupted sunlight can improve efficiency. Installing offshore floating solar systems close to the shore remains challenging because tides, winds and saline water can damage the panels. Bird droppings can also reduce efficiency, while cleaning is more difficult. A floating solar project typically has a lifespan of around 20 years. Most solar panels are mounted on floating platforms, or pontoons, with metal frames that allow them to be tilted at the optimum angle to maximise sunlight. Anchoring and mooring these platforms remain significant engineering challenges.

Globally, some solar panels are also installed directly over water surfaces with suitable protective covers, helping to conserve water by reducing evaporation. The panels also help keep the water beneath cooler, thereby further limiting evaporation. India has around 150 large hydropower plants, besides several medium and smaller ones. According to the first national water bodies census published by the Ministry of Jal Shakti, India has 2,424,540 enumerated water bodies, including ponds, tanks, lakes and reservoirs. Furthermore, India has a declared network of 111 National Waterways spanning more than 20,187 km.

The leading operational project is NTPC's 100 MW floating solar project at Ramagundam in Telangana, located within its thermal power complex. The 600 MW Omkareshwar project in Madhya Pradesh is under implementation. NTPC has also commissioned a floating solar project at Kayamkulam in the backwaters of Kerala.

Other projects under implementation include those at the Rihand Reservoir and several additional NTPC projects. Among the most significant proposals is the Sardar Sarovar Project, a multi-state project with a potential capacity of 5,000 MW. Preliminary work has already been undertaken, and following its approval in July, the project is expected to be implemented in phases between 2027-2029. Another major opportunity is the Indira Gandhi Canal, which passes through Punjab, briefly through Haryana, and into the Thar Desert in Rajasthan.

While a floating solar project requires higher capital investment than a land-based solar project, it generally delivers higher energy yields. The estimated cost of a floating solar project is approximately R3.85-4.10 crore per MW, compared with R3.30-3.80 crore per MW for a ground-mounted solar project. Thermal power projects remain the most expensive option. Solar power is also significantly cleaner and is not dependent on volatile raw material prices such as coal. In addition, thermal power plants typically require 5-7 years to build, whereas a solar project can usually be completed within 12-24 months.