The lure of floating solar plants

Water is emerging as the new land for solar plants in India, and around the world

The concept is simple. Since large parcels of land are not easy to acquire, or are just not available in some countries (think Bangladesh, Japan or Singapore), why not use the real estate presented by water bodies to set up floating solar plants. This technology has given four advantages. These are that the water has a cooling effect on the system and therefore may increase generation, that the existing transmission infrastructure of the reservoir can be put to good use, that evaporation of a scarce resource like water can be prevented, and that knotty people displacement issues can be avoided. To top that, the cost of floating solar is coming down fast.

According to Xiao Fuqin, deputy general manager at Sungrow Floating, a unit of Sungrow Power, floating solar costs have fallen by 44 per cent over the last two years. He was speaking at a conference in Shanghai earlier this month. 

NTPC has plans for several hundred megawatts of floating solar plants in the country, and aims to take a lead in the sector.

In November last year, Shapoorji Pallonji Group bagged 50 megawatts in the floating solar auction on the Rihand reservoir in Uttar Pradesh by the state-run Solar Energy Corp of India at a tariff of Rs 3.29 per unit.

Last week, Singapore sought proposals for a 50 megawatts plant that “will be one of the largest single floating solar PV systems in the world when it is completed.”

Norway’s biggest utility, Statkraft, began construction of its first floating solar plant earlier this year, in Albania, and is currently scouting for project opportunities in India. A competitive tariff remains the key consideration, however.

Kerala State Electricity Board (KSEB) has an operational 0.5 megawatts floating plant in the reservoir contained by the Banasura Sagar dam that survived the 2018 floods. It stands on a hollow ferro-cement floater that almost replicates land on water — no ripples are felt on the platform — though its high cost would prevent it from becoming the platform of choice for new plants. 

There are over 1.3 gigawatts of floating solar plants globally, according to BloombergNEF. China leads installations, though India is expected to become another of the big four markets.

In Chile, a small floating solar plant has been installed by Anglo American on top of the tailings dam that holds liquid waste from copper mining operations. Thermal power generation companies with reservoirs at the plant site are also looking at the option of using the surface area of the water to generate power. 

It is possible that floating solar ends up becoming cheaper than ground-mounted solar. KSEB’s executive engineer, Ayyub Kunnanolli, was confident that it would be so: “Land cost will go up as availability goes down. Float cost will (ultimately) become lower than land cost.”

The Solar Energy Corporation of India has issued a tender for 20 megawatts of floating solar plants, with 60 megawatt-hours of storage, spread across 11 Lakshadweep islands. The closing date has been extended to August 5, 2019.
 

The author is editor, Global Policy for BloombergNEF. 

Email: vgombar@bloomberg.net