The two main power sources for powered industrial trucks are internal combustion, which uses a traditional engine that runs on liquid petroleum gas (LPG), compressed natural gas (CNG), gasoline, diesel, or other fuel, and electric, which uses an on-board battery. This section provides information on these power sources, including some of the potential hazards and possible solutions associated with their use and with refueling and battery charging/changing operations.

Other power sources that may become more widespread in the future include fuel cells and hybrid systems. Hydrogen fuel cells will have zero emissions and quiet operation plus the ability to be refueled as quickly as gasoline engines. Hybrid systems will use a combination of fuel cells and batteries.