Governors' Wind Energy Coalition

SINGAPORE — After years of experiments on floating solar power pilot projects, the technology is closing in on commercialization.

Singapore’s national water and utility authority is finalizing contracts for construction of a large-scale solar power plant that would be floated on the Tengeh Reservoir in the country’s West Region.

The Public Utilities Board (PUB) is requesting enough floating solar photovoltaic (PV) panels to generate 50 megawatts of electricity at peak capacity, making it “one of the largest single floating solar PV systems in the world when it is completed.”

PUB’s goal is to have the system up and running by 2021.

“The floating Tengeh system will eliminate the need to emit 28,000 tons of carbon dioxide every year that it is in operation,” PUB said in a statement. “This is equivalent to removing 6,000 cars off our roads.”

Other floating solar projects exist, including a large trial system in Japan, but the technology has yet to take off, relative to offshore wind or land-based solar power.

But proponents of the technology say floating solar technology is gaining popularity.

The technology, they say, can solve three problems: Managers of reservoirs or other inland water bodies can put surface area to economic use. In hot, dry climates, covering reservoirs with solar panels also cuts down on water losses to evaporation. And the systems allow countries with limited land to build their own large-scale renewable power systems, rather than depending solely on widely scattered rooftop panels.

“The Singapore government from the start has been very supportive of floating solar; it has been a first mover in that field,” said Céline Paton of the Solar Energy Research Institute of Singapore (SERIS). “Now there are already two projects that have been tendered.”

Paton and her team have been running experiments with floating solar for three years, beginning with small pilot systems also set up in the Tengeh Reservoir. A much smaller demonstration unit floats in waters adjacent to the Marina Bay Sands hotel and entertainment complex in the city’s southern harbor.

As Paton explains it, the concept isn’t as straightforward as making solar panels that float.

Even in calm waters, there is constant motion that stresses the racking systems and connectors. SERIS launched 10 pilot projects beginning in 2016, with each system using not only different panels but also different floats, connectors and, in some cases, different converters.

Data collected thus far shows that floating solar requires much more careful monitoring and maintenance than land-based systems.

“It’s only about three years old, so it’s still a little bit young to make long-term conclusions, but what we are certainly seeing is that it’s very important to do a proper … operation and maintenance of the systems; otherwise, there might be fatigue that you can see,” Paton explained. “It’s always moving on the water, so with time, you have the connections between the floats that might get moved a little bit, so that really needs to be properly dealt with … even in a stable environment.”

Paton sees the government’s formal request for proposals for a 50-MW system as a sign that floating solar is about to become mainstream. She predicts many more projects to come as plans proceed throughout the world, pointing to activity in the Netherlands and elsewhere.

“There are more and more countries interested in the technology,” she said. “Europe is also now really developing new projects.”