Introduction
Tuas Power’s Tembusu Multi‑Utilities Complex (TMUC), located on Jurong Island, is currently Singapore’s sole coal-fired power and steam cogeneration plant. According to government figures, coal makes up around 1% of Singapore’s power-generation capacity and is used only at TMUC.
In a significant move for the city-state’s decarbonisation agenda, TMUC is now planning to convert its coal-biomass co-fired boilers to run on 100% biomass feedstock by around 2027-28.
This transition marks a major step in Singapore’s climate strategy and reflects broader regional trends in energy transition, feedstock sourcing, corporate responsibility and regulatory oversight.
Background: TMUC and Singapore’s Coal Position
Historically, unlike many major economies, Singapore has operated with a minimal share of coal. According to the Energy Market Authority (EMA), the only plant in the country using coal is TMUC.
Opening in 2013, TMUC was designed as a multi-utility complex providing both electricity and high-pressure steam (for industrial use) and utilising a mix of low-ash/low-sulphur coal and biomass fuel.
Importantly, Singapore has pledged to phase out “unabated” coal by 2050 under its membership of the Powering Past Coal Alliance (PPCA).
In parliamentary replies, the government emphasises that the timeline for TMUC’s transition will depend on the remaining asset life of the plant and the availability of viable alternatives for the industrial steam customers.
Thus, while coal only accounts for a sliver of Singapore’s generation mix, TMUC plays a strategic role because it supplies both power and steam to heavy industrial users on Jurong Island.
The Conversion Plan to 100% Biomass
According to recent market reports, Tuas Power intends to convert TMUC’s cogeneration boilers—currently co-firing coal and biomass—into a fully biomass-fired operation by about 2027-28.
Key details of the plan include:
- Switch from coal-biomass mix (currently around 70% coal / 30% biomass) to 100% biomass feedstock.
- Annual biomass consumption post-conversion projected at more than 1.3 million tonnes per year for about 135 MW electrical capacity plus steam output.
- Feedstock sourcing comprising two main channels: imported palm kernel shells (PKS) from Malaysia and Indonesia (≈ 1 million t/yr) and domestic wood waste/horticultural residues (≈ 300,000 t/yr) from Singapore.
- The conversion deadline: operations expected to begin around 2027-28 with a feedstock swap.
Because TMUC is the only facility of its kind in Singapore still burning coal, this conversion would effectively end coal use in Singapore’s power sector (barring waste-to-energy/incineration, etc.), aligning with the national decarbonisation strategy.
Implications for Singapore’s Energy Transition
Decarbonisation & Strategy
Switching TMUC to biomass helps Singapore move closer to its goal of phasing out unabated coal by 2050. While coal currently contributes little to its overall generation mix, eliminating that final 1% is symbolically and substantively important.
Moreover, analysts note that biomass conversion of TMUC is technically feasible but challenging due to feedstock availability and cost.
Industrial Utility and Reliability
The plant’s dual role—supplying steam and power to chemical/industrial users on Jurong Island—makes the conversion technically more complex than a standard power plant. The business model must be maintained during transition, meaning reliability, fuel logistics, thermal output must all be safeguarded.
Feedstock & Supply-chain Considerations
Moving to biomass at this scale raises significant logistical questions:
- Securing certified, sustainable biomass imports (PKS) in large quantities.
- Ensuring domestic waste/horticultural feedstock collection and processing.
- Mitigating risks of feedstock price volatility, supply chain disruptions, certification/traceability issues.
Regulatory & Financial Aspects
The Singapore financial sector is increasingly focusing on coal-phaseout standards. For instance, the Monetary Authority of Singapore (MAS) is consulting on early phase-out criteria for coal plants in the Singapore-Asia taxonomy.
Thus, TMUC’s transition will likely also play into broader “transition finance” debates: how legacy thermal assets can shift to low-carbon operations, how to account for stranded-asset risks, and how to ensure emissions reductions have integrity.
Challenges & Risks
Despite the positive direction, the transition faces several practical challenges:
- Feedstock scarcity: Singapore lacks large agricultural residues; it must rely heavily on imports. That raises sustainability, cost and logistics concerns.
- Technology and conversion risk: Converting boilers to run 100% biomass may require retrofit, operational changes, and assurance of performance.
- Cost and competitiveness: Biomass fuel has lower calorific value relative to coal and sometimes higher cost; that may impact economics or pricing for industrial customers.
- Operational disruption: Ensuring the supply of steam and power during conversion is critical given industrial dependency.
- Environmental trade-offs: Importing biomass raises questions about sourcing, forest impact, certification, and cross-border supply chain sustainability.
What It Means for Singapore’s Energy Mix & Emissions
Singapore’s energy mix is overwhelmingly gas-based (more than ~90%), with coal contributing around 0.9–1% of electricity generation according to the Economic Development Board.
By converting TMUC, the country can practically eliminate coal from the mix domestically, focusing future efforts on solar deployment, electricity imports, hydrogen, and other low-carbon technologies.
Given that TMUC is also an industrial-utility plant (steam + power), its shift to biomass sends a strong industrial decarbonisation signal beyond just the power sector.
Wider Regional and Global Context
Singapore is part of a broader Southeast Asia effort to transition from coal, retrofit existing plants, or convert to biomass/co-firing. For example, regional studies show the average age of Southeast Asian coal plants will allow profitable retirement by 2030-35.
In this context, TMUC’s conversion can serve as a case study: showing how a high-value industrial cogeneration plant can shift feedstock rather than just decommission.
Financial frameworks such as transition credits (developed by MAS) also aim to incentivise coal-to-clean transitions.
What to Watch Next
- Announcement of official plan by Tuas Power: While market reports exist, company confirmation of timing, feedstock contracts, and investment will be key.
- Signing of biomass-feedstock supply agreements: Secure sourcing from Indonesia/Malaysia + domestic waste streams.
- Retrofitting timeline and boiler conversion details: How the conversion will be staged, whether coal is gradually phased out, what technical modifications occur.
- Impact on steam/offtake contracts on Jurong Island: Any changes to industrial steam delivery, pricing implications, business continuity.
- Monitoring of emissions outcomes: Will the shift deliver measurable CO₂ reductions and improve operational carbon intensity?
- Policy/regulatory support: Government incentives, potential feed-in tariffs, biomass certification standards, industrial decarbonisation support.
Conclusion
In summary, Singapore is taking a compelling step in its energy transition by converting its only active coal-based utility plant—TMUC on Jurong Island—from coal-biomass co-firing to 100% biomass feedstock by around 2027-28. This move aligns with national decarbonisation commitments, addresses industrial cogeneration needs, and places Singapore within regional coal-to-clean transition momentum.
Still, the journey is not without risk: feedstock supply chains, retrofit investment, business continuity and cost competitiveness remain challenging. If all goes well, however, TMUC’s transformation could provide a blueprint for how industrial-grade utility plants can evolve in a low-carbon future.
