Life Cycle Global Warming Impact of Long-Distance Liquid Hydrogen Transport from Africa to Germany

Abstract

The global interest in hydrogen as an energy carrier is steadily increasing. In this study, multiple scenarios of liquid hydrogen exports from Africa to Germany are analyzed by life cycle assessment (LCA) to quantify the global warming potential (GWP) of 1 kg hydrogen. The investigation is driven by the promise that hydrogen can be sustainably and economically produced by photovoltaic (PV)-powered electrolysis in Africa, benefiting from the geographical location near the equator and, consequently, higher solar irradiation levels. Given the absence of a pipeline network, shipping hydrogen emerges as the most efficient short-term transportation option to Germany. In this paper, supply locations—Morocco, Senegal, and Nigeria—are evaluated by means of an LCA and compared to hydrogen supply from Germany. Results show that emissions from hydrogen production and transportation by ship from Morocco range from 3.32 to 3.41 kgCO2-eq/kgH2. From Senegal, the range is 3.88 to 3.99 kgCO2eq/kgH2, and from Nigeria, it falls between 4.38 and 4.27 kgCO2-eq/kgH2. These emission levels are influenced by factors such as the GWP of PV electricity, the efficiency of the electrolyzer, and the transportation distance. Interestingly, the analysis reveals that PV-powered electrolysis of hydrogen in Germany, including 300 km distribution, causes, in most scenarios, a lower GWP in the range of 3.48 to 3.61 kgCO2-eq/kgH2 than hydrogen from the analyzed African regions. Opting for grid electricity instead of PV (with a value of 0.420 kgCO2-eq/kWh) for hydrogen production in Germany yields a GWP ranging from 24.35 to 25.42 kgCO2-eq/kgH2. Hence, we can conclude that in any event, PV-powered hydrogen electrolysis has a low environmental impact not only within Africa but also in Germany. However, it is crucial to carefully consider the balance of the GWP of production versus transportation given the distance between a hydrogen production site and the location of consumption.