How are Environmental Impact Assessments (EIAs) conducted for floating photovoltaic (PV) farms in Singapore?
Let’s break down the Environment Study Report for the upcoming nearshore floating photovoltaic (PV) farm at Pulau Sebarok.
Author’s note: The report was previously made available for public view on the EDPR website when public feedback was sought. It has since been removed.
To begin, where is Pulau Sebarok?
Pulau Sebarok is a 46.8-ha island (or 87.5 football fields) off the southern coastline of Singapore, and accessible via a short ferry ride from Singapore mainland. The property features large oil storage tanks with dedicated pipeline systems, pumps, roadways and ancillary buildings.
A floating photovoltaic (PV) farm is set to be deployed approximately 290 m off the southeast tip of Pulau Sebarok to decarbonise energy consumption on Sebarok.
The project is led by Singapore-based company EDP Renewables (EDPR; which has a 91% stake in Sunseap, exploring the use of dead sea space to testbed the potential of near-shore floating solar platforms. Dead sea space refers to maritime waters that are not usable for other purposes or are already unusable due to existing use of the area.
The solar energy produced will be provided to the petrochemical storage terminal on the island, replacing some of its existing diesel-generated energy and reducing the terminal’s carbon emissions.
The system is expected to generate an energy output of 1.2-megawatt peak to support energy demand on the island, which can power ~100 households in Singapore.
What might the PV farm look like?
Sunseap intends to deploy two Ocean Sun Floating Photovoltaics (FPV) farms.
The Ocean Sun system consists of a 75m floating buoyancy ring fitted with a hydro-elastic membrane, with PV modules fitted in. The floaters are then anchored to the seabed through a mooring system that consists of mooring ropes and concrete sinkers. There will be no anchor to the shoreline.
As the development is located near the shoreline of Pulau Sebarok, which is host to local marine wildlife, EDPR has engaged a consultant to conduct an Environmental Impact Assessment (EIA) to assess the potential environmental impact of the floating platforms and reported findings in the published Environment Study Report.
What is the EIA process?
The Environment Study Report outlines:
- Scope and approach of the project
- Environmental baseline i.e. understanding the current state in the study area (presence and conditions of sensitive receptors)
- Impact predictions of the different phases of the project: (i) Construction (2 weeks), (ii) Operation (20 years), (iii) Decommissioning
- Proposed mitigation measures
The flowchart below outlines the impact assessment process.
How is impact measured?
The environmental screening for this project was conducted at the end of 2021. Potential impacts were identified by developing a Scoping Matrix — a way to organise findings from the baseline survey by measuring the potential impact of potential environmental pressures on environmental receptors.
- Environmental pressures = Changes in the environment resulting from the project. These include physical presence/ disturbance, light penetration, water temperature, water quality etc.
- Environmental receptors = Social, economic or ecological features that may be affected by the pressure. These include corals, marine fauna, avifauna, jetties etc.
As outlined in the flow chart (in the previous slide), all identified impacts will be assessed using the Rapid Impact Assessment Matrix (RIAM), recommended by the Biodiversity Impact Assessment Guidelines of Singapore.
Using a formula, RIAM calculates the Environmental Score using five evaluation criteria:
- Importance
- Magnitude
- Permanence
- Recoverability
- Cumulative impact
The scores will then determine the level of impact significance (from no impact to major negative or positive).
Outcomes for Sebarok?
The study has assessed that there is minor to no significant impact within the study area as the platforms and its mooring system will avoid the coral-populated shoreline. The seabed underneath the platforms consists of a mixture of coral rubble and rocks with no coral or seagrass communities.
Should we still be concerned?
We might want to take note of a few potential impacts during the operational period of 20 years:
- Scouring of seabed — Installation and removal of concrete sinkers, cables and other related structures may cause souring of habitats if not done properly i.e. dragged along seabeds instead of being dropped or lifted directly, affecting corals and other benthic organisms.
- Direct habitat loss (7.1.3.1) — Should movement of the cables occur frequently, the cables may drag against coral and cause damage. Additionally, beacons are expected to be installed just off the shoreline of Pulau Sebarok for navigational safety. The exact placement or design of these beacons has not been confirmed, but could potentially be placed in existing coral habitats and result in further habitat losses.
- Reduction in light availability (7.1.3.3) — In the longer term, FPVs may cause some effects on the health and functioning of subtidal, intertidal and macrobenthic habitats due to the shading effect of the physical structure. A reduction of light availability can also reduce surface phytoplankton production, causing knock-on effects for other organisms that depend on them. As there are currently few existing FPVs globally, empirical studies on their impacts are limited.
- Coral study (7.1.4) — A coral mapping exercise is recommended before the deployment of the concrete sinkers but has yet to be conducted. Since anchoring is necessary, instead of relocating the corals, could coral-friendly sinkers or anchors be explored for areas with close to no impact significance?
The good news is that they are considering coral-friendly mooring systems in their mitigation measures, where it is stated that concrete sinkers and cables could be designed to provide new substrate for benthic species to colonise and function as an artificial reef.
For example, by increasing crevices and pits to create topographical complexity, instead of smooth surfaces. But they only stand as proposed considerations for now. It is unclear if these designs will be implemented. (We are unaware of what designs exist for now — if you do, email us and let us know!).
What are some of the proposed mitigation measures in the report?
To highlight a few:
Construction
- Careful placement of concrete sinkers during installation should ensure minimal impact on the seabed e.g. dropping instead of dragging.
- Concrete sinkers are to be shifted as far away from coral habitats as possible to avoid scouring.
Operation
- FPVs are located 8.6m away from the nearest coral habitats, as such, unlikely to have any appreciable impact from the reduction of light.
- Avoid excess slack in the design of mooring lines and ensure the sufficient weight of concrete anchors to minimise the scouring of the seabed.
Decommissioning
- Careful removal of concrete sinkers or leaving concrete sinkers in place for those located within the coral reef crest.
- Removal and transplantation of benthic organisms found to be growing on concrete sinkers. Relocations of nests found on PV panels to other suitable nesting sites.
So, what happens next?
While EIAs are essential tools for identifying and mitigating potential environmental impacts, their effectiveness depends on the engagement and enforcement of project developers to implement mitigation measures. This means some projects may not fully implement the recommended mitigation measures.
Furthermore, with the time lag between the baseline study and actual project implementation, EIAs may not fully account for impacts in the dynamic environment.
What do you think? Are EIAs sufficient to ensure that the proposed mitigation measures will be implemented?
This article is Part Three of a four-part series in collaboration with LepakinSG.
To learn more about Singapore’s Energy Landscape and Solar Development and Floating Photovoltaics (FPVs) in Singapore, check out Part One and Part Two on Instagram!
About Energy CoLab
Energy CoLab is a community of learning. We design and organise meaningful learning and networking opportunities for young people in Singapore to spark curiosity towards sustainable energy transitions, with a focus on the social aspects that are often overlooked.
Our main focus is to work with various stakeholders across disciplines to make energy-related topics more accessible, engaging and inclusive, and to reduce barriers that many youth face in contributing solutions to energy issues.
About LepakinSG
LepakinSG is an informal environmental group — with the keyword being informal!
We work towards a world where Singapore does its fair share to limit global temperature rise to 1.5 degrees, where Singapore limits consumption of resources to what the Earth can regenerate in a year, and where Singapore reduces biodiversity loss to no more than the background extinction rate.
