HELIUMPOWER ENERGY
Technology

CCGT
Thermal.

Combined-Cycle Gas Turbine (CCGT) technology represents the pinnacle of thermal power efficiency. By capturing and reusing waste heat from a gas turbine in a secondary steam cycle, CCGT plants achieve net electrical efficiencies of up to 64% — roughly double that of older open-cycle plants — while operating with the fast-start flexibility that modern grids demand.

64%
Peak thermal efficiency (CCGT)
< 30 min
Cold-start to full load
99.5%
Plant availability target
40+ yrs
Typical asset design life
How It Works

The Combined
Cycle Process.

01

Gas Turbine Combustion

Natural gas (or hydrogen blend) combusts in a gas turbine, spinning the primary generator. Exhaust temperatures reach 600°C.

02

Heat Recovery Steam Generator (HRSG)

The hot exhaust gases pass through the HRSG, producing high-pressure steam — capturing energy that a simple-cycle plant would waste to atmosphere.

03

Steam Turbine Generation

The recovered steam drives a secondary steam turbine, typically adding 30–40% of primary output. This two-stage process is what achieves the 60–64% overall efficiency.

04

Combined Output to Grid

Both generators synchronise to grid frequency. The plant operators can ramp output from minimum stable generation (MSG) to full-load in under 30 minutes.

Applications

Flexible.
Dispatchable. Efficient.

Peaker Plants

Fast-start CCGT plants filling the gap between baseload and peak demand. Critical for grid stability as renewable penetration grows.

Baseload Capacity

Highly efficient combined-cycle baseload plants operating at high capacity factors in markets with low gas prices and carbon pricing.

Hydrogen-Ready Design

Our CCGT designs incorporate hydrogen co-firing capability, positioning assets for the energy transition to green hydrogen.

Grid Balancing

Fast-ramping CCGT plants provide frequency response and spinning reserve — revenue streams increasingly valued by grid operators.

Key Advantages

Why CCGT?

CCGT plants bridge the gap between the need for reliable dispatchable power and a net-zero future. Their inherent flexibility and declining carbon intensity through hydrogen co-firing make them the thermal technology of choice for the energy transition.

Highest efficiency of any fossil-fuelled generation technology at 60–64%
Fast start and ramp: from cold to full load in under 30 minutes
Significantly lower CO₂ per MWh than coal (approx. 50% less)
Hydrogen co-firing capability as decarbonisation pathway
Modular, scalable plant sizes from 50 MW to 2,000+ MW
Low water consumption compared with conventional steam plant

Developing a thermal generation project?

Talk to our CCGT engineering and development team.