Singapore has limited land space, but is keen to expand its solar PV panel count to keep emissions down. The only place it can put them is on water. By Jeremy Torr

Singapore, March 2021. Singapore is famous for its clean, neat appearance, it’s efficient social structure – and its great food. It is a leader in a less positive way too: it has one of the worst emissions rates per capita of any country in the world.

This is partly because of the population density on the island, but also because it has to power everything by fossil fuels. It is one of the biggest carbon dioxide emitters per capita, and its densely populated nature makes the city a tricky place to install alternative, more sustainable power supply options. There are no dams, no turbines, and unlike Nordic countries no wind to help minimise oil and gas consumption. So the government is looking hard at solar energy to produce power that meets its electricity needs.

Jen Tan, Head of Solar at power company Sembcorp explains that this is not as straightforward as it seems, despite the country being near the equator with plenty of solar energy beaming down every day. The one thing solar farms need is space – and Singapore is not space rich.

“We have exhausted all the available space we have on rooftops, so we have to look elsewhere,” explains Tan. “We see the next big potential is water areas. Tan explains that as a relatively small, flat island, Singapore has had to be very careful about its water supplies, and has built many reservoirs in strategic positions across the country.

“This means we have got many reservoirs, a lot of areas that we can use for dual-use. That means we can have floating solar panels and reservoirs at the same time.”

The two bonuses are that the reservoirs are flat and stable and unoccupied, but also that the installation of floating PV panel farms shades the water and helps cut down valuable drinking water evaporation. It really is a win-win innovation.

Local group SunSeap has already installed several successful pilot plants on local reservoirs, and is currently working on what will be the biggest floating solar platform in Southeast Asia, covering an area equal to 45 football pitches on Tengeh Reservoir and laden with more than 122,000 solar panels and reducing around 32 kilotons of carbon emissions annually—the same as removing 7,000 cars from Singapore roads for a year. And having proved the potential of floating PV farms, they are also looking now at sea-installed floating farms. At the moment, however, one of the newest solar farms to be built is in the Johor Strait which separates Singapore from Malaysia. Around 13,000 panels have been anchored to the seabed with the capacity to produce five megawatts of electricity - which should power 1,400 apartments a year, with a reduction in greenhouse gas emissions of about 2,600 tonnes every year, over the next 25 years and more.

This approach has opened the door for Singapore to deploy much more ambitious systems. It is looking at even bigger installations that could produce up to 1GW solar farms. The novel floating approach brings an added bonus as the water the farms float on can help keep the panel temperature down in the tropic heat, allowing greater output per panel than otherwise might have been the case.

But there are still hurdles to overcome, as Sunseap’s Head of Engineering, Shawn Tan, notes. He explains that the waters around Singapore that could potentially house bigger solar farms are very congested due to the heavy traffic in and out of the port. “We are constantly looking for new areas,” he says.

The Singapore government plans to increase national solar energy use four-fold, to quadruple its solar cell output in coming years, and to potentially generate just under 5% of the country's power needs by the next four years. This would be enough for approximately 350,000 households a year.

It’s a sound option. “I don’t think we have a choice,” says Subhod Mhaisalkar of Nanyang Technological University. “We have to consider every possible option, and now are looking to make up 10-20% of Singapore’s long term (power) needs with solar.”