Semakau Landfill beyond 2035

Semakau Landfill is home to the Renewable Energy Integration Demonstrator-Singapore (REIDS), the largest micro-grid testbed in Southeast Asia. Initiated by Nanyang Technological University’s Energy Research Institute, the microgrid connects various forms of renewable energy technologies developed by the Research and Development Labs of over 30 local and international companies into an intelligent renewable energy system.

These technologies include the 42.5 metre tall wind turbine developed by French low-carbon solutions company ENGIE Lab and 9500 square metres of solar panels. Independent and detachable from central power grids, the micro-grid is regarded as a technology that would function as a self-sufficient local energy infrastructure and is being tested at REIDS for its applicability in other more isolated parts of Southeast Asia. The micro-grid will eventually occupy 64000 square metres of land and include a hydrogen-based energy storage system.  

Supported by the Singapore Economic Development Board, REIDS is one example amongst others of Singapore's "tech business experimentalism." REIDS exemplifies how Semakau is presented as an exceptional space for global technology firms to develop various cutting edge technologies on the landfill island's premises due to its geographical and business conditions.

Semakau Landfill serves as a testbed location due to its offshore tropical island status that has similar conditions of heat and humidity to the target Southeast Asian communities. This small developmental testbed of prototypes seeds hopes of exportable solutions that will develop the economies of these more distant communities. Meanwhile, the island itself serves as a functional showcase of the capacity of these technologies. Its experimental energy infrastructure has provided electrical power to the Barramundi Asia fish farm on the island, thus giving Semakau Landfill the reputation of a ‘clean’ trash island -- as in ‘clean technology.’ 

Operational since 2008, Barramundi Asia’s 7.5-hectare fish farm cultivates barramundi (otherwise known as Asian Sea Bass or Giant Perch) which is sold in Australia, Singapore, Hong Kong and the United States under the Kühlbarra brand. The fish are first bred as fingerlings in nurseries that employ the Recirculating Aquacultural System (RAS), which re-filters water in automated closed indoor tanks. They are then reared and monitored in large floating sensor-monitored High Density Polyethene (HDPE) cages in the sea before they are harvested and packaged. In 2019, Barramundi Asia commissioned an offgrid solar PV and battery system, adding to Semakau’s ‘clean’ reputation, and expanded its fish farm nursery, which demonstrated a commitment to supporting the Singapore government’s efforts in boosting food security.

Food security is a critical challenge as Singapore imports over 90% of its food from a range of countries as less than 1% of the city-state’s land area is allocated to local farming. However, the fish farm experienced an outbreak of “Scale Drop Disease Virus” in late 2021, which has led to an evacuation of the remaining fish from its premises in Semakau and hence a scaling down of its operations. It remains to be seen if the fish farm will weather through and expand again from this development. Nevertheless, this highlights how more diseases emerge as environmental conditions change and raises questions on how Singapore could maintain the stability of its food security strategies.  

Prior to the Landfill construction, Pulau Semakau and Pulau Sakeng had a thriving community of islanders for more than a hundred years. Between 1988 to 1993, benthic community diversity at Pulau Semakau was in rapid decline due to dredge spoil disposal into the sea bed between Pulau Semakau and Pulau Sakeng. Upon completion of the Landfill in 1999, much of the mangrove forests and coral reefs on the eastern side of Pulau Semakau were decimated. Two plots of mangroves were subsequently replanted to replace the 13.6 hectares lost to the construction.

As the artificial land circuit expanded in 2014-2015 into the Landfill’s lagoon, over 700 coral colonies were harvested and relocated to Sisters’ Islands Marine Park, including a Neptune's Cup Sponge which was thought to be extinct since 1908. Thus, in contrast to its environmentally sustainable image, the Landfill has likewise contributed to marine habitat displacement and destruction.

Scaling up from the Landfill’s status as a renewable energy testbed, plans for Semakau’ solar farm will be more ambitious as the remaining landfill cell grows into land that could potentially be used for solar deployment. By 2025, 60-hectare of the Landfill will be transformed into a Solar Park with a capacity of at least 72 megawatt-peak.

The solar-derived electricity will be exported via a submarine transmission cable to the neighbouring Pulau Bukom where Shell’s Energy and Chemicals Park is located, to be used as a renewable energy source. This is following in the mould of previous solar farms such as the 45-hectare floating solar panel farm in Tengah Reservoir, which was, at one point of time, one of the world’s largest floating solar panel farms with 122000 solar panels. The Solar Park will demonstrate Singapore’s and their investors’ commitment towards a low-carbon infrastructure future with the installation of the solar farm on the landfill island, which will be the world’s largest yet. 

This would be a contrast to the neighbouring Pulau Bukom, an island which has long functioned as the site of an oil refinery complex but will be increasingly made obsolete by global market trends that discourage fossil fuel consumption. However, not all crude oil-related infrastructure will be completely dismantled, such as Shell’s Single Buoy Mooring (SBM) pipeline, as fossil fuel use continues beyond 2040 especially with respect to shipping.

From 2030 to 2040, Singapore will be phasing out the use of Internal Combustion Engine vehicles on the road for electric vehicles. This development will build upon the increased general use of solar energy which has been pushed by the government’s commitment towards increasing its renewable energy capacity and energy efficiency since 2025. Beyond 2050, Semakau will see the continuous phasing out of solar panels. Research will be conducted on recycling of solar panels as building construction materials which could be incorporated in land reclamation processes. 

With at least sixteen years passed after the launch of the Zero Waste Masterplan and the institution of the Resource Sustainability Act, Singapore would have seen the implementation of the Circular Economy principles of reducing and reusing waste in the various stages of the product supply chain with respect to its waste streams which include electronic waste, paper and plastic. The target to reduce the waste sent to Semakau Landfill will be partially achieved through public educational campaigns on recycling and on reducing food waste, new uses for the incineration ash, the compliance of companies in declaring and recycling their electronic and packaging waste, and the brief and ultimately unsuccessful waste rationing scheme, in which citizens have to accountable for tracked waste disposed into Smart bins and, in more extreme cases of trash disposal, fined.

But this target of waste reduction will be surpassed by the steady stream of incinerated waste supplied by its population of 6.5 million people, whereby it will become evident to everyone that Semakau Landfill cannot be ‘saved.’ Instead of the tagline of ‘#SaveSemakau,’ Semakau Landfill will be given the moniker of ‘Zero-Waste Island.’ Marketed as an island of cutting-edge green technologies in which every square inch is optimised for maximum yield in energy and production output, the Landfill will be the physical embodiment of the Circular Economy. It will demonstrate the self-sufficiency associated with the concept as well as the profitability of reducing -- within practical means -- and reusing waste.    

By 2035, parts of Semakau Island’s landfill cells will be used for the testing of new reclamation materials. These experiments will be extensions of existing projects which transform Incinerated Bottom Ash into construction material, such as NEWSand.

Semakau Island’s experiments will complement other experiments in petrol substitution in the Southern Islands, such as the pyrolysis plant on Pulau Bukom that will recycle plastic waste to create pyrolysis oil.

In 2045, a new phase for Semakau Landfill will commence as the lagoon becomes visibly negligible as seen from satellite imagery. Tests on the possibility of repurposing incinerated bottom ash and incinerated fly ash as construction material achieve some degree of success. However the toxicity and consistency of these components continue to pose challenges to their extended use, especially on mainland Singapore. Hence, studies are conducted on the existing dumping ground located beyond the bund created in Phase II as the site of possible landfill cell expansion. Since 2001, the Singapore Concept Plans and Land Use Plan have marked the sea space between Pulau Semakau, Pulau Jong and Pulau Sebarok as an area for possible future reclamation for the longer timeline of 2050 and beyond (see Figure 2). The reclamation, if carried out, will have a significant adverse impact on mangrove forests, seagrass meadows and coral reefs that serve as blue carbon sinks as well as refugia for wildlife.

For this reason, the site of possible landfill cell expansion will be on the southwest end of the Landfill, away from the blue carbon ecosystems. A perimeter bund will be constructed to enclose 370-hectare sea space into landfill space. In doing so, a new landfill cell will be created to form Phase III of the landfill to meet Singapore’s future waste disposal needs beyond 2050.