Generation Station

Thermal Power Plant. The fuel is pulverized coal or natural gas. Older plants may use oil. The fuel is
mixed with air and burned in a boiler that generates steam. The high-pressure and high-temperature
steam drives the turbine, which turns the generator that converts the mechanical energy to
electric energy.
Nuclear Power Plant. Enriched uranium produces atomic fission that heats water and produces steam.
The steam drives the turbine and generator.
Hydro Power Plants. A dam increases the water level on a river, which produces fast water flow to drive
a hydro-turbine. The hydro-turbine drives a generator that produces electric energy.
Gas Turbine. Natural gas is mixed with air and burned. This generates a high-speed gas flow that drives
the turbine, which turns the generator.
Combined Cycle Power Plant. This plant contains a gas turbine that generates electricity. The exhaust
from the gas turbine is high-temperature gas. The gas supplies a heat exchanger to preheat the
combustion air to the boiler of a thermal power plant. This process increases the efficiency of the
combined cycle power plant. The steam drives a second turbine, which drives the second generator.
This two-stage operation increases the efficiency of the plant.

Source:
Karady, George G. “Transmission System”
The Electric Power Engineering Handbook