An improved apparatus supplies gaseous fuel from a liquid state to an internal combustion engine comprising an electrical energy generating apparatus for generating electrical energy from a store of chemical energy. A liquid pumping apparatus for pumping the gaseous fuel in the liquid state includes an energy converter for converting the electrical energy to mechanical energy which drives the liquid pumping apparatus. The liquid pumping apparatus also includes a first heat exchanger for vaporizing the gaseous fuel received from the pumping apparatus and a controller programmed to operate the liquid pumping apparatus to maintain a pressure of the gaseous fuel supplied to the internal combustion engine within a predetermined range.