A 300MW addition to Norochcholai should provide 1,800GWh (at 75% plant utilisation). To match this, we need 1,200MW of floating solar PV – to be installed in Puttalam lagoon – using 725ha, a mere 2% of the lagoon surface area. This can be broken into 12 islands of 100MW (and have multiple parties compete for them), and phase out across say two years. 

The transmission lines from Norochcholai can easily accommodate the system (since the system will be fully loaded only for four hours per day around 1,000MW). The hydro displaced during the daytime from the system can easily ensure plenty of it is left for the evening peak even during the harshest drought.

The capital costs for the system would be $ 900 million, which can be fully funded through private sector equity and debt. While initial costs are slightly more expensive than the planned coal plant ($ 630 million), the electricity from the FSPV will come without an additional fuel cost, hence cheaper.

The system can be connected faster – a coal plant takes a at least four years to build, but the approval and environmental clearance taking a minimum of three years. Globally, a coal plant takes seven to 12 years to build and some projects stay at various stages of approval for over 10 years before getting cancelled. Floating solar will avoid protracted legal battles, civil society unrest and protests, and give certainty to the grid and the nation of real low-cost electricity. No mafias will be involved.

Powering Sri Lanka through renewables: The floating solar opportunity