A method and device to optimize the cumulative beneficial effect of harvesting all available forms of lost energy, including energy that is lost while a vehicle is in motion (e.g., kinetic, inertia, friction, thermodynamic, and aerodynamic losses). The cumulative energy that is recovered is converted to electrical energy which powers the on-board electrolyzer to produce more hydrogen and oxygen while the system is in operation and stationary. Stationary, passive means of energy, solar, wind, hydro, etc. will also be available to power the electrolyzer. The system also contemplates utilizing passive means of energy to power a non-mobile system which incorporates an internal or external combustion engine in place of a fuel cell.