The Turbine Talk: One-on-one with Vogt at AMC 2026

Vogt Power International + Hanwha Power: What Low-Load HRSG Operation Is Actually Doing to Your Equipment

The grid has changed, and combined-cycle plants are being asked to do things they weren't originally designed to do. Extended low-load operation is one of them. Vignesh Bala, Director of HRSG Services at Vogt Power International, sits down with Matt Yaquinto, Hanwha Power's Senior Manager of Combustion and Digital Programs, to talk about what happens to an HRSG when it runs at low load for extended periods, and what plant teams can do about it.

Vogt Power has been manufacturing and servicing HRSGs for over 60 years, with more than 600 units operating across 40 countries. Critically, their service work is not limited to Vogt-built equipment; they work on HRSGs from any manufacturer, which gives them a broad view of how different designs respond to operating conditions that have changed significantly from original design intent.

The connection to gas turbine operations is direct. A combustion upgrade or a change in turbine dispatch profile changes the exhaust characteristics entering the HRSG: temperature, flow rate, and emissions profile all shift. That means the thermal and mechanical stresses inside the HRSG shift too, and low-load operation amplifies some of the more damaging effects. This conversation covers:

• Thermal and mechanical challenges at low load: What is actually happening inside the HRSG during extended low-load periods, and which components bear the most stress.
• Reliability and asset life implications: How low-load cycling patterns accelerate degradation mechanisms that are manageable under normal operating profiles but become more serious under sustained flexibility dispatch.
• Design considerations: What to look for in HRSG design and configuration if low-load operation is a regular part of the plant's operating mode, either by current dispatch requirements or anticipated future ones.
• Operational adjustments and maintenance practices: Practical changes in how an HRSG is operated and maintained that can reduce the rate of damage accumulation without requiring capital investment.

The conversation is well-timed. Renewable penetration is not reversing, and the flexibility requirements placed on thermal generation assets are going to continue increasing. For any plant running a combined-cycle unit with significant cycling or low-load operation, this is a practical technical briefing on the risks and the options.