Life cycle environmental and economic analyses of a hydrogen station with wind energy

摘要

This study aimed to identify the environmental and economic aspects of the wind-hydrogen system using life cycle assessment (LCA) and life cycle costing (LCC) methodologies. The target H_2 pathways are the H_2 pathway of water electrolysis (WE) with wind power (WE[Wind]) and the H_2 pathway of WE by Korean electricity mix (WE[KEM]). Conventional fuels (gasoline and diesel) are also included as target fuel pathways to identify the fuel pathways with economic and environmental advantages over conventional fuels. The key environmental issues in the transportation sector are analyzed in terms of fossil fuel consumption (FFC), regulated air pollutants (RAPs), abiotic resource depletion (ARD), and global warming (GW). The life cycle costs of the target fuel pathways consist of the well-to-tank (WTT) costs and the tank-to-wheel (TTW) costs. Moreover, two scenarios are analyzed to predict potential economic and environmental improvements offered by wind energy-powered hydrogen stations. In LCA results, WE[Wind] is superior to the other pathways in all environmental categories. The LCC results show that the projected WTT cost savings of WE[Wind] and WE[KEM] compared to gasoline are US $ 0.050 and US $ 0.036 per MJ, respectively, because hydrogen will not be subjected to any fuel tax according to the Korean Energy Policy in 2015. Although WE[KEM] and WE [Wind] incur high capital costs owing to the required capital investment in fuel cell vehicles (FCVs), they have lower well-to-wheel (WTW) costs than those of conventional fuels due to the high FCV efficiency in fuel utilization stage. WTW costs for gasoline are higher than those of WE[KEM] and WE[Wind] by US $ 12,600 and US $ 10,200, respectively. This study demonstrated the future competitiveness of the WEfWind] pathway in both environmental and economic aspects. In the WTT stage, the point-of-sale of the electricity produced by the wind power plant (WPP) cannot be controlled because the wind-powered electricity production fluctuates considerably depending on the wind. However, the use of a wind-powered H_2 station in the future enables stable wind power plant management and provides greater economic profit than the present system since the wind-powered electricity can be used for the hydrogen production in the H_2 station and any residual electricity is sold to Korea electric power corporation (KEPCO). If 5% of conventional vehicles in Korea are substituted with FCVs using H_2 via WEfWind] in 2015, CO_2 emission will be reduced by 2,876,000 tons/year and annual LCC costs by US $ 8559 million. Thus, the operation of wind-powered hydrogen stations will encourage the introduction of hydrogen into the transportation fuel market.