Life Cycle Energy and GHG Emissions Analyses Results

2 Life Cycle Energy and GHG Emissions Analyses Results 

The life cycle energy and GHG emissions findings are presented in Table 8. The total primary energy embodied in the life cycle of the H2 production and distribution system is 35.8 MJprim/kg of delivered H2. Of the total life cycle energy, the PV power plant accounts for 50%, filling stations account for 22%, the pipeline system accounts for 19%, the electrolysis plant accounts for 5%, and the city gate distribution centers account for 4%. 

The primary energy payback time is 3.1 years, and the GHG emissions payback time is 3.1 years. With a thirty year life cycle for all system components and the replacement of gasoline ICE vehicles with H2 FCVs, the payback time estimates translate into vehicle operation with 27 years of fossil fuel free energy use and zero GHG emissions. The sensitivity results indicate that a + 25% change in all life cycle estimation parameters change the primary energy payback time by + 0.80 years and the GHG emissions payback time by + 0.81 years. 

7 System Energy Flow/Mass/Balance Analysis 

System components Primary energy (MJprin/kg H2) CO2 eq emissions (kg C02/kg H2) Payback sensitivity of energy to +/- 25% (Years) Payback sensitivity of GHG emissions +/- 25% (Years) 

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