Harnessing the Power of the Sun and Water to Secure a Cleaner Energy Future

Carbon emissions reduction and climate resilience are firmly on Singapore’s change agenda. Currently relying on imported natural gas to fulfil 95% of its electricity needs, the city-state is taking the ambitious step of diversifying its energy mix and shifting toward renewable alternatives for a cleaner, more affordable and more resilient energy future.

Averaging around 5.5 hours of sunshine every day, solar is shaping up to be the preferred technology to deliver its vision for a better energy future. Singapore plans to scale-up its solar capacity to 2 gigawatt-peak by 2030 and has already announced plans to install solar panels on available surfaces across land and rooftops. But how does a country with a severe shortage of available land and a high-density, urbanized population find enough space to generate all that capacity? National Water Agency PUB is looking to its reservoirs for answers.

Powering energy-intensive waterworks with ‘green’ power

Turning challenges into opportunities for innovative developments has long been part of PUB’s DNA. In Singapore, raw water undergoes a stringent, robust and complex treatment process to emerge from our taps as clean and wholesome, safe for consumption without the need for filtering or boiling. This makes water treatment an energy-intensive process. One of PUB’s ambitious goals is to tap on solar power to reduce its carbon footprint and improve environmental sustainability of its operations. But not just any solar, floating solar photovoltaic systems.

With a shortage of available land and an abundance of water surfaces, floating solar PV is a viable alternative to traditional rooftop or ground solar photovoltaics applications in Singapore. We’ve been working with PUB since 2018 to develop the option of installing floating solar photovoltaic (PV) panels on the water surface of its reservoirs to harness energy from the sun. Earlier this year, we were commissioned to put the concept to the test.

Our team provided engineering services, including financial assessment, PV system simulation, conceptual and detailed design, construction supervision and commissioning services, for the installation of two 1.5 megawatt-peak (MWp) floating solar PV systems on Bedok Reservoir and Lower Seletar Reservoir, covering a total of 2.5 hectares of water surface. The floating solar PVs will produce enough green power to satisfy 30% of the energy requirements of adjacent PUB installations - Bedok Waterworks, Bedok and Lower Seletar raw water pumping stations.

Developing a safe and reliable system for a drinking water reservoir

Installing solar arrays on water has some unique challenges. Bedok and Lower Seletar Reservoirs play host to a variety of water activities such as canoeing, kayaking and dragon boating. Our design team worked closely with PUB to ensure that recreational activities are not affected. The floating solar PVs occupy less than 2% of the reservoir’s surface area. Physical barriers have also been installed around the perimeter of the floating solar panels.

The deployment of solar PV panels in drinking water reservoirs could potentially raise concerns about possible contamination from pollutants leaching out of the PV materials. Hence, we have stipulated stringent material qualities for all components of the floating solar PVs to preserve the quality of the reservoir water. The standards set for the assessment were to exceed international benchmarks to ensure no compromise to water quality and safety.

Integrating the new PV system with existing PUB installations

With the installation of a new electrical source, it was critical to ensure proper integration of the floating solar PV with the electrical system of PUB’s existing installations. Leveraging our intimate understanding of PUB’s installations and operations, our team developed electrical system studies, equipment specification and new operating procedures with PUB to ensure the integration was seamless and posed no risks to existing operations.

A lookahead toward a cleaner energy future

Together, the two floating solar PV systems will have a total potential capacity of 3MWp of clean, green energy every day. That’s equivalent to the electrical consumption of about 800 four-room flats per year and will reduce PUB's annual carbon emissions by around 1.5 kilotonnes – equivalent to removing 300 cars from Singapore’s roads.

The project is expected to complete in 2021.

“We’ve leveraged our global expertise in renewable energy and our regional and local expertise in marine, structural and electrical systems to develop an innovative solution that helps PUB overcome multiple challenges in this first-of-its-kind project,” says Jacobs People & Places Solutions Technical Director Water in Asia Colin Newbery.

The floating solar PV project is part of PUB’s solar deployment plan to install solar panels across its facilities (on rooftop and reservoirs), including one of the world’s largest single floating solar PV installation on Tengeh Reservoir. With the completion of the Tengeh floating solar PV system in 2021, PUB will be able to generate sufficient power to meet the energy needs of all five local waterworks (i.e. water treatment plants), making water treatment in Singapore 100% green.

Looking ahead, Singapore’s solar future is looking bright and PUB is on track to ensuring the nation’s water and energy security, and contributing to climate change mitigation efforts through the adoption of cleaner energy.