Combined cycle generators use a combination steam turbine/gas turbine configuration to generate electricity. Gas turbine exhaust can be used to generate steam which in turn can be used to make even more power in a steam turbine. This combined cycle process achieves a very high efficiency in the conversion fuel energy to power.

When a dependable and reasonably priced supply of natural gas and/or good quality fuel oil is available, combined cycle can be used for base-load power generation, especially where some or all of the steam leaving the steam turbine can be used by an industrial process.