SINGAPORE - Having grown its solar capacity by more than seven times since 2015, Singapore is now one of the most solar-dense cities in the world.
The Republic took one big step towards environmental sustainability when its first large-scale floating solar photovoltaic (PV) system at Tengeh Reservoir - about the size of 45 football fields - was officially opened on Wednesday (July 14).
Prime Minister Lee Hsien Loong was the guest of honour at the event.
This latest solar farm in Tengeh, which has a capacity of 60 megawatt-peak (MWp), will contribute to the country's plan to install at least 2 gigawatt-peak of solar PV capacity by 2030.
The project will give the nation's solar and renewable energy industry a boost, paving the way for more such facilities to be built here and in the region, Mr Lee said.
The idea of building a floating solar farm came up a decade ago when Singapore was looking for ways to harness solar energy at scale. This became an increasingly viable option as the cost of solar cells came down.
Building a floating solar farm also helped to capitalise on the large surface area of reservoirs and allow for solar deployment to be scaled up, the PM added.
Spread across 10 solar-panel islands, the 122,000 solar panels on the surface of Tengeh Reservoir comprise one of the world's largest inland floating solar PV systems.
The energy generated there will go into the national electricity grid, with the full capacity of the solar farm providing enough power for about 16,000 four-room Housing Board flats for a year.
Alternatively, that is more than enough to power the operations of Singapore's water treatment plants that treat reservoir water to produce clean drinking water to the entire nation, Mr Lee said.
In 2016, national water agency PUB and the Economic Development Board launched a 1MWp test bed at Tengeh Reservoir, which showed that a floating solar farm was feasible and did not affect surrounding wildlife or water quality.
The test bed also performed up to 15 per cent better than a conventional rooftop solar power system due to the cooler reservoir water, Mr Lee said.
He added: "Because the pilot was successful, we are now building similar floating solar farms at Bedok and Lower Seletar reservoirs, which we expect to complete later this year."
The floating solar farm at Tengeh is designed, built, owned and operated by Sembcorp Floating Solar Singapore in partnership with PUB. It was completed in less than a year, despite manpower and resource challenges caused by Covid-19.
The bulk of the construction started last December.
Sembcorp's engineers came up with their own techniques to boost productivity, such as by building a device that sped up the assembly of the solar panels to the floats by up to 50 per cent.
Amid the Covid-19 pandemic earlier this year, assembling just 1,200 solar panels a day was difficult. But productivity improvements saw the number of solar panels assembled peaking at around 1,800 to 2,000 a day
A digital monitoring system has also been set up to monitor the health of the solar farm.
And as dirt on the panels can reduce operational efficiency, they are tilted at a slight angle to allow rainwater to wash it off.
Drones with thermal-imaging capabilities will also be deployed to detect any faulty panels.
Gaps between the solar panels allow sunlight to pass through and deployed aerators will maintain oxygen levels in the water, reducing the impact on biodiversity and water quality of the reservoir, Mr Lee said.