Sembcorp Tengeh Floating Solar Farm


Modeling and simulations to assess the microclimate surrounding floating solar arrays  

The floating solar arrays on the Tengeh Reservoir in Singapore comprise one of the world’s largest inland floating solar farms at 60 MWp. The arrays occupy approximately one third of the surface of the reservoir (45 hectares), with over 122,000 solar panels across 10 floating PV “islands”. The energy it produces offsets about 32,000 tons of carbon emissions each year, equivalent to taking 7,000 cars off the road.


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  • The Challenge

    The floating nature of these solar PV panels posed several challenges:

    • The shading effect of the panels could reduce the solar radiation absorbed by the water, resulting in a lower overall water temperature
    • The solar energy not converted into electricity and the energy landing on the floats will heat the solar arrays, potentially increasing heat transfer to the water surface and evaporation rate
    • Changes in air temperature and humidity around the PV islands could impact the flora and fauna in the reservoir and the surrounding forest
  • Our Approach

    As part of this project, RWDI’s team of experts:

    • Reviewed on-site climate data and conducted parametric simulations of an analytic model of a PV island to understand the range of conditions the arrays will be exposed to and the sensitivity of the islands’ air , heat, and moisture transport to various climatological parameters. This allowed for the identification of the most important climate scenarios from the perspective of heat exchange between the islands and their surrounds. These scenarios were then simulated in greater detail in the flowing phases of work.
    • Conducted detailed CFD simulations of an isolated array under select environmental conditions (determined in the step above) to estimate key performance parameters (wind drag, amount of heat transferred to water vs air, etc.)
    • Leveraging the above analyses, large scale CFD simulations of the solar arrays, reservoir and the surrounding forest were then undertaken. They predicted the impact of the arrays on the microclimate of the reservoir and forest, including water and air temperature changes as well as changes to evaporation rates and humidity.
  • The Outcome

    RWDI’s expert contributions to this project helped determine the impacts of deploying this large-scale floating solar PV system on the Tengeh Reservoir. Similar experimental studies were conducted at a smaller installation planned for the Upper Peirce Reservoir. Since the project’s official opening in July of 2021, the floating panels at Tengeh have been found to perform up to 15% better than the typical rooftop PV system in Singapore, without a significant impact on surrounding wildlife or any observable change in water quality to date.