Abstract
This is a conceptual study, for MW to GW scale, comparing production, transmission, and storage costs for gaseous hydrogen (GH2) and anhydrous ammonia (NH3) fuels made from wind-generated electricity, with and without the low-cost, annual-scale, firming storage which would add great market and strategic value. Both fuels are suitable for vehicles and for distributed generation (DG) in stationary combined-heat-and-power (CHP), via fuel cells or internal combustion engines (ICE's). NH3 is also a valuable fertilizer, and this study briefly examines the economics of renewable-source versus fossil-source production of NH3 fertilizer. No pilot plant exists for confirming the system capital costs and conversion efficiencies we estimate in this study, although both GH2 and NH3 have been proposed for wind energy transmission and storage [1–6]. Hydrogen is promising as a clean-burning energy carrier, and modern electrolyzers can produce large volumes of high-pressure hydrogen, ready for direct pipeline transmission and/or for ammonia synthesis, from renewable energy sources. Renewable-source hydrogen can alternatively be stored and transported as NH3, which can be readily synthesized, following electrolysis, using atmospheric nitrogen, and be used at the delivery end-point as a fertilizer or a fuel. Both GH2 and NH3 transmission and firming storage will accelerate our conversion from fossil to diverse renewable resources, via major new markets including, and beyond, the electricity sector.