A drilling system comprises a tubular member disposed in a wellbore having a downhole assembly disposed therein. At least one electrical device is disposed in the downhole assembly. A fuel cell is disposed in the downhole assembly and operatively coupled to the electrical device for providing electrical power thereto. The fuel cell extracts at least a portion of its fuel supply from the flowing drilling fluid downhole. In another aspect, a pipeline system comprises a pipeline having a fluid flowing therein. An electrically powered device is disposed in the pipeline. A fuel cell is operatively coupled to the electrically powered device for providing electrical power thereto. The fuel cell extracts at least a portion of a fuel supply from a fluid flowing in the pipeline.