Thermal Efficiency
The percentage of fuel energy that a thermal power plant converts into electricity. The rest is waste heat. Typical values: coal 33-37%, gas CCGT 55-63%, nuclear 32-34%, gas simple cycle 30-40%.
Why It Matters
Higher thermal efficiency means more electricity from less fuel — reducing both cost and emissions. This is why CCGT plants displaced less efficient coal plants when gas prices dropped.
Related Topics
Related Terms
Heat Rate
A measure of power plant efficiency — the amount of fuel energy (in BTU) needed to produce one kilowatt-hour of electricity. Lower heat rates mean higher efficiency. A typical CCGT has a heat rate of about 6,400 BTU/kWh.
Combined Cycle Gas Turbine (CCGT)
A power plant that uses natural gas in two stages: first burning it in a gas turbine, then using the waste heat to produce steam for a steam turbine. This two-stage process achieves 55-63% thermal efficiency — the highest of any thermal power plant.