Hot Ambient Solution for IGT25 Gas Turbine

What it offers

IGT25-HAS or Hot Ambient Solution is an upgrade of IGT25 aiming to improve performance at high ambient temperature. It will increase the power up to 2 MW and thermodynamic cycle efficiency up to 1.3% (relative) or 0.4% (absolute) at target ambient temperature of 50°C. The main target here is to have the minimum cost. So, the major upgrade is based on compressor improvement. New IGV tuning and stator blades re-staggering are the solutions to increase the compressor mass flow rate and maintain the compressor efficiency respectively.

Other modifications include control logics (control system) re-adjustment and new stagger angle setting for the first vane of the power turbine. The most important advantage of HAS upgrade is producing the required power at high ambient temperature with no life reduction.

The upgrade has been designed to be performed during level B or level C maintenance plan of the IGT25 with the same downtime as before.

Make the most out of the engine!

Increase in Production
Higher Efficiency
Environmentally Friendly
Reliability and Availability
Life Extension

What You Gain

IGT25-HAS Up to 2 MW power & 1% efficiency at 50 ⁰C

Air Compressor

  • New IGV control logic
  • New stagger angle for the   compressor stators

PT Turbine

  • New Stagger angle
  • New power turbine adjustment

A glimpse into the new design

These modifications need low, yet highly reasonable expenditure to be made to the gas turbine during the maintenance intervals. The main concept of IGT25-HAS is to increase the compressor mass flow rate while maintaining its efficiency to produce more output power at 50 ⁰C ambient temperature. It is accomplished by opening the IGV in hot ambient temperature and compressor stators re-staggering to modify the component efficiency. The power turbine stator angle is adjusted to meet the swallowing capacity. A comparison of HAS version to IGT25 is shown in the below figures. The product has been designed to maintain the IGT25 reliability, availability and maintenance plan. The same emission will be expected and Surge margin is generally kept the same as IGT25.


This upgrade offers higher cycle efficiency and output power at high ambient temperatures (which is common for IGT25 gas turbines to experience an ambient temperature above 35°C). The upgrade is also recommended for the sites which cannot produce the minimum required power at high ambient temperature. The variation of gas turbine output power and efficiency with ambient temperature are shown in figures below.