This work presents a technical and economic analysis of a power supply system based on a 5 kW Proton Exchange Membrane Fuel Cell (PEMFC) fed with hydrogen produced by the auto-thermal reforming of ethanol. The technical analysis is based on unpublished experimental data obtained from the prototype of an ethanol reformer developed by the Hydrogen Laboratory at Unicamp and by Hytron, which represents the state-of-the-art of this technology in Brazil. The results point out that the cost of the hydrogen produced by the ethanol reformer prototype is lower than the hydrogen prices in the Brazilian market, and that the cost of the electricity produced by that hydrogen in a PEMFC is lower than other alternative sources of energy, except when compared to the electricity available in grid-connected power system in Brazil.