NOVELTY - A portion of a hydrous ethanol and/or primary fuel such as diesel or gasoline is provided to a power source or an internal combustion engine (18) with combustion chamber (30) igniting by compression, spark or homogeneous charge compression ignition. A second portion of the hydrous ethanol is supplied to a fuel cell (46) with fuel processor. Combustion results in formation of an exhaust-gas stream. A third portion of hydrous ethanol is provided to the exhaust-gas stream exposed to a selective catalytic reduction system catalyst.    USE - For reducing pollutant emissions of a power system such as an internal combustion engine of earth moving machine such as an excavator, a dozer, a loader, a backhoe, a motor grader, a dump truck, highway vehicles such as tractors, passenger cars, heavy and light trucks, and other similar vehicles, fixed machines and furnaces.    ADVANTAGE - Since hydrous ethanol is less reactive than pure fuel-grade ethanol and hydrous ethanol additives may be stored at equilibrium, requirements for storage and transportation of a hydrous ethanol additive is lower than for storage and transportation of pure fuel-grade ethanol. This leads to significant cost savings over pure fuel-grade ethanol and other benefits such as, cooler combustion chamber temperatures and reduced combustion chamber production of nitrous oxide. Also, by using parts designed specifically designed for ethanol e.g. plastics, damage to parts can be reduced or eliminated. Injection of an ethanol additive into an intake port prior to combustion may allow for greater mixing of any remaining ethanol within an exhaust-gas stream. Complete mixing of ethanol within the exhaust-gas stream may be beneficial to increasing the reduction efficiency of an SCR system catalyst. By combining an SCR system catalyst with intake port injection of ethanol, results in increased efficiency of the reaction between NOx and ethanol contained in the exhaust-gas stream, as the stream contacts the SCR system catalyst. Also, by allowing a portion of the ethanol to be combusted in combustion chambers may further result in benefits to brake specific fuel consumption, while leaving an amount of unburned ethanol in the exhaust-gas stream. This remaining amount may be sufficient to facilitate catalytic reduction reactions and may improve the efficiency of an SCR system catalyst. By using the ethanol additive enables reduction in petroleum based fuel use and little or no pollutant emissions. By determining which power source is better suited to provide power for a particular request, power needs may be met while also minimizing overall pollutant output.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for    (1) system for reducing emissions;    (2) machine    DESCRIPTION OF DRAWING(S) - The drawing schematically illustrates first and second power sources.    Internal combustion engine (18)    Intake passage (24)    Intake manifold (26)    Combustion chamber (30)    Fuel cell (46)