Gas Turbine Ambient Temperature Lapse Rate Calculator
Calculate gas turbine electrical output derating (MW) and heat rate change as ambient air temperature rises above ISO standard baseline (15°C / 59°F).
Turbine ISO Rating & Site Weather
Hot-Weather Derate & Recovery
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Tested hardware and components for high reliability
Frequently Asked Questions
Why does hot ambient temperature reduce gas turbine power output?
Warm air has lower density. Because the axial compressor moves a constant volumetric displacement, warmer air reduces the mass flow of air entering the turbine combustor, directly decreasing generated shaft power.
Why are aeroderivative turbines more sensitive to ambient temperature than heavy industrial frames?
Aeroderivative engines operate at much higher compression pressure ratios (30:1 to 40:1 vs 16:1 to 20:1 for heavy frames), making compressor discharge temperature limits more constraining in hot weather.
How much power can inlet evaporative cooling or chilling recover?
Evaporative cooling typically recovers 60% to 80% of the hot-weather power loss in arid climates, while mechanical inlet air chilling can lock compressor inlet temperature at 10°C year-round regardless of ambient heat.