Floating a solar alternative

The Energy and Resource Institute (TERI) has been exploring a ‘third pillar’— floating solar photovoltaic — to boost solar electricity generation in the country. With a shortage of land, and high land prices for installation of solar systems at the ground level, it felt that placing solar panels on water bodies may be an alternative worth looking into.

With this in mind, last month, it released its research report on the potential of Floating Solar PV (FSPV), which involves placing solar panels on large and medium water bodies to generate electricity. This is being currently done in several countries, with China leading the way, followed by Japan and South Korea. India too has one or two small projects, but considering that it has large waterbodies distributed across the country, it could make this an opportunity.

However, TERI found that there was no single-point database available to study how far it was possible to install floating solar panels. Painstakingly, the researchers collated material from a host of databases, to put together a State-wise at-a-glance map of the potential of FSVP, taking into consideration different scenarios, including the depth and the age of each water reservoir.

A web-based user interactive tool — India Floating Solar PV-Tool — was also put in place. The findings concluded that about 18,000 km2 water surface area is available and suitable for FSPV plants across a host of States and Union Territories, with possibility of generating as much as 280 GW.

There are several pluses for floating solar, including the fact that installation is simpler and requires no civil work at the site of the plant. The floating platforms on which solar PV arrays are mounted are prefabricated and interconnected to form a large section.

The platform is first assembled in a lab by adding rows of modular interconnecting floats and these together form a large platform. The plant is constructed on land and then towed to the water body location.

Implementation challenges

However, the report points out a number of challenges that need to be addressed for floatovoltaics technology to be an alternative for States to consider. “The waterbody is moving and could have certain turbulence, therefore mooring and anchoring of the PVs is a critical element, along with the stability of the platform and ensuring that it does not pollute the water body,” explains Dr Ashwini Kumar, Senior Director, Renewable Energy Technologies, TERI. He says manufacturing challenges could be overcome by manufacturing locally, though it would be important to adhere to strict standards and special tests as platforms need to be extremely robust.

“The government’s latest directive for “Make in India’ that for anything less than ₹200 crore you do not require to go in for a global bid could help small projects. Around 50 MW can be constructed under that,” says Kumar, as he reveals that the research has generated considerable interest among States.

TERI has got feelers from Maharashtra, Telangana and Karnataka. It has signed an MoU with state-owned NHPC Limited to probe the possibility of setting up floatovoltaics at its hydro power plants as there is good synergy between the two. TERI will also be engaging with Jawaharlal Nehru Port Trust in Navi Mumbai, Calcutta Electric Supply Corporation in Kolkata, and Tata Steel.

Now, for the crucial issue of cost. Currently in the country, ground-based installation of solar PV dominates the sector at 93 per cent, with roof top solar contributing the rest. Between 2010 and 2018, the price of solar energy has declined by 84 per cent and makes us the country with the lowest installation costs. Can the same happen with floatovoltaics technology, which at present is in a very early stage of development in the country?

While the report finds FSPV technology “promising to become a third pillar of the solar PV sector and its market share is likely to accelerate,” it feels there is a lot to be ironed out before hurrying into large-scale deployment. “In this initial stage, focus must be on the viability of FSPV as a technology and not on the tariff and hence monitoring of its performance and bringing it to public domain must be encouraged,” it concludes.

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