How does a CCGT work?

03/07/2025

Find out how combined-cycle gas turbine (CCGT) power plants generate electricity and contribute to the transition to ever more affordable, available and sustainable energy.

Infographics "How does a CCGT work?" - see detailed description hereafter
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How does a CCGT* work?

  1. Ambient air is compressed and headed to the combustion chamber.
  2. Natural gas is injected. At combustion chamber exit, the temperature of the gases is around 1,300°C.
  3. The expansion of the hot gases triggers the rotation of the gas turbine’s shaft.
  4. Hot Flue Gases (550°C) are headed to the inlet of a head recovery steam generator.
  5. The expansion of steam triggers the rotation of the steam turbine’s shaft.
  6. Low pressure steam condenses through a cooling system and is pumped back to the steam generator at low pressure level.
  7. The generator produces electricity, 2/3 of which comes from the gas turbine and the remaining third from the steam turbine.
  8. The electricity generated is fed into the high-voltage grid.

* CCGT: Combined Cycle Gas Turbine.