Advanced Gas Turbine Exhaust Systems – Delivering Hydrogen-Ready Infrastructure for Southeast Asia

Case Study

July 2025

Client Location:

Singapore

Project Duration:

Fabrication/Delivery Aug 2023 – Oct 2024

Installation support:

February – April 2025

Divisional Lead:

EGL Baltec – A Division of The Environmental Group Limited

Project Scope:

Design, engineering, fabrication, and delivery of two Gas Turbine Exhaust Stack Systems for dual 340 MW M701F-series turbines

Project Overview

In pursuit of a net-zero future, Singapore is investing in cutting-edge power generation infrastructure that can support flexible fuel operations, including hydrogen co-firing. In alignment with this national energy strategy, EGL Baltec was commissioned to design and deliver two complete Gas Turbine Exhaust Stack Systems for new 340 MW Open Cycle Gas Turbine (OCGT) units, each with the capability to co-fire with up to 30% hydrogen—and upgradeable to 100% hydrogen in the near future.

EGL Baltec, backed by The Environmental Group, led this highly specialised project from conceptual design through to fabrication, shipping, installation and commissioning and will support the project with ongoing maintenance services and spare parts. As a result, the systems are now undergoing installation and commissioning, marking a milestone in the region’s transition to sustainable, reliable energy.

Engineering World-Class Gas Turbine Exhaust Systems

Each exhaust stack system stands 34.3 metres tall, positioned 10.89 metres from the gas turbine interface. At the core of the design is an advanced acoustic and structural enclosure engineered to manage extreme thermal, acoustic, and aerodynamic loads:

Silencer Design: Each system features industry-leading Gas Turbine Silencers with a 9.35 metre square internal gas path—the largest ever supplied by EGL Baltec, with gas pressure drop levels under 175mmWC. The Silencers are designed specifically for peaking units where daily starts are common. As a result, these silencers will operate reliably for many years.

Noise Control: The silencer and enclosure are engineered to comply with strict near-field and far-field noise limits—85 dB(A) at 1 metre and 65 dB(A) at 56 metres A fully integrated 23-metre-high structural housing with roof was designed in-house to meet performance and site-specific acoustic attenuation requirements

Thermal Safety: Surfaces are thermally managed to maintain external temperatures below 55 °C, ensuring operational safety and compliance.

Scope of Supply

End-to-end engineering design including CFD and acoustic modelling
Custom silencer R&D, incorporating innovative splitter technology
Project management and detailed structural design
Fabrication of complete stack systems totalling 1,308 tonnes
International shipping logistics and site installation support
Integration of emissions monitoring systems, with access platforms and electric hoists

Project Impact and Community Benefit

Why These Gas Turbine Exhaust Systems Matter for Southeast Asia

Beyond its technical achievements, this project is helping to shift the regional energy narrative. Hydrogen-capable power infrastructure offers nations like Singapore a critical bridge between existing generation technologies and a low-emissions future. By investing in infrastructure that can scale with emerging fuel sources, this project reduces dependency on carbon-intensive generation and enables a more resilient energy mix for the region.

Importantly, the design ensures that this transition does not come at the cost of local amenity. The noise and heat mitigation measures built into our stacks meet the regulatory and contractual requirements.

In doing so, EGL Baltec has demonstrated how environmental engineering—done well—not only reduces emissions but supports the kind of energy evolution that keeps cities liveable, industries productive, and grids secure.

Notable Achievements

Engineering Milestone: Development and delivery of the largest gas path silencers in EGL Baltec history.

R&D Innovation: Acoustic splitter R&D resulted in optimal silencer configuration, meeting all noise guarantees. Thermal and structural design is optimized for peaker applications and thermal cycling ensuring reliable operation over many starts.

Structural Integration: Fully integrated acoustic enclosure—designed and engineered by EGL Baltec—meets the highest global standards.

Client Satisfaction: Feedback confirms precision-fit components and ease of site installation

Future-Proofed: Designed for 100% hydrogen adaptability to meet evolving decarbonisation mandates

Driving A Sustainable Energy Future

This project exemplifies The Environmental Group’s mission to engineer a more sustainable future. Through EGL Baltec’s world-class engineering capabilities, we continue to support the global transition to cleaner energy while maintaining the reliability and safety standards critical to industrial-scale power generation.

By partnering with governments, communities, and forward-thinking clients, we are proud to play an integral role in building the infrastructure needed for tomorrow’s energy landscape—today.