A Fuel Plant is a Base Module that can convert Hydrogen Gas, Coal, Petroleum, and Methane into Energy. A Fuel Plant consumes Oxygen Gas when burning these fuels.
Burning Hydrogen Gas creates Water and Water Vapor as a by-product. Burning the other three fuels, all Fossil Fuels, produces Carbon Dioxide.
You can configure when a Fuel Plant starts or stops the production of Energy based on the stores of fuel, Oxygen, and Energy you have.
A Fuel Plant can be connected to another Fuel Plant or an Engineering Hallway.