From the Introduction: "This report is focused on the current and potential sources of hydrogen, and several of the various technologies and processes for its economic production and use. Replacing fossil fuels with hydrogen for the generation of electricity may provide one potential avenue for reducing GHG [greenhouse gas] emissions. However, hydrogen production and technologies to use hydrogen as a fuel for power generation currently present higher cost options, if the potential negative externalities of carbon dioxide emissions are not considered."
CRS Report for Congress, R46436
Congressional Research Service: https://crsreports.congress.gov/