Combined Cycle Gas Turbines (CCGT).

Currently, burning gases in a boiler is the only option in the game, which works well for the early to mid-game. However, there is a much more interesting alternative to boilers. Gases and certain liquid fuels can be combusted directly inside a turbine system.

The concept is simple: a Gas Turbine operates similarly to a Steam Turbine, but its working fluid is the hot exhaust gas from burning gaseous fuel rather than steam. This turbine directly drives a generator. Crucially, the exhaust from this gas turbine is hot enough to boil water for a secondary steam turbine cycle.

Ideally, this machine should be a single, compact module. It would take in Gas and Water, and output Electricity, Exhaust Gases, and Depleted (Low-Pressure) Steam. Generally, this combined-cycle approach boasts an efficiency of 60–65%, compared to just 40% for a standard steam-only cycle.

Proposed balancing metrics:

• A base recipe of 72 Gas + 48 Water should output 23–25 MW of power, along with 48 Exhaust Steam and standard emissions depending on the fuel type.
• For the final end-game variant, a consumption of 96 Hydrogen/Gas per 60 seconds would yield 36 MW of mechanical shaft power. After conversion losses, this nets exactly 30 MW of electrical power, representing a highly realistic 60% total plant efficiency.