Sembcorp and PUB open the Sembcorp Tengeh Floating Solar Farm

Sembcorp Floating Solar Singapore, a wholly-owned subsidiary of Sembcorp Industries, and Singapore’s national water agency PUB, have officially opened the Sembcorp Tengeh Floating Solar Farm at the Tengeh Reservoir. With 122,000 solar panels spanning across 45 hectares, the 60MWp solar photovoltaic (PV) farm is dubbed one of the world’s largest inland floating solar PV systems.

The commencement of the solar farm’s operations marks a significant step towards enduring energy sustainability in water treatment, making Singapore one of the few countries in the world to have a 100% green waterworks system while contributing to the national goal of quadrupling solar energy deployment by 2025.

The electricity generated from the solar farm will be sufficient to power Singapore’s five local water treatment plants, offsetting about 7% of PUB’s annual energy needs and reducing PUB’s carbon footprint.

Ng Joo Hee, chief executive of PUB, said: “With this floating solar power plant, which we believe to be one of the largest in the world, PUB takes a big step towards enduring energy sustainability in water treatment. Solar energy is plentiful, clean and green, and is key to reducing PUB’s and also Singapore’s carbon footprint.”

A new logo created based on PUB’s iconic “Make Every Drop Count” water droplet was also unveiled at the event to mark this achievement of a fully green water treatment system. The droplet features an iconic sun and rays of sunlight to highlight how clean water is now produced from clean energy. It signifies PUB’s commitment to combat climate change by ensuring end-to-end sustainability in its operations, contributing towards the sustainability goals under the Singapore Green Plan 2030.

Construction of the floating solar PV system commenced last August. Designed, built, owned and operated by Sembcorp, the project was completed on time will safe management measures in place, despite manpower and supply chain constraints due to the unprecedented COVID-19 pandemic.

New and innovative ways of working were needed to mitigate the impact, and one such way was conceptualising and implementing a new engineering and construction technique to design a custom-built jig that increased the rate of solar panel assembly by up to 50%.

Partnering with Quantified Energy Labs, a technology spinoff from the National University of Singapore, this project also deploys advanced drone electroluminescence imaging technology on a utility-scale PV system. Drone electroluminescence imaging captures X-ray-like signals emitted by PV modules to accurately and rapidly pinpoint defects that could be caused by a variety of factors from the manufacturing to installation stage. Identifying and replacing defective modules from the start has ensured that the PV system us running in optimal condition.

PUB’s main concern with deploying solar panels on reservoirs was the potential impact on surrounding environment, biodiversity and water quality. A comprehensive Environmental Impact Study, which included biodiversity surveys, water quality monitoring and modelling, along with consultations with nature groups was carried out between 2015 and 2018. Results from PUB’s testbed deployed at Tengeh Reservoir in 2016 showed “no observable change” in water quality nor significant impact on surrounding wildlife.

Referencing the study, the Sembcorp Tengeh Floating Solar Farm was designed to minimise impact on the reservoir’s water quality, flora and fauna. Sufficient gaps between solar panels were incorporated to improve the airflow and allow sufficient sunlight to reach aquatic life. Additional aerators were also put in place to maintain oxygen levels in the reservoir.

Floats deployed are made using high-density polyethylene (HDPE). In addition to having a comprehensive environmental management and mitigation plan, PUB and Sembcorp will continue to monitor the reservoir closely, and take necessary measures to maintain biodiversity and water quality.