Electrofuels or hydrogen as marine fuel: a cost comparison

Other conference contribution, 2017

Electrofuels (elsewhere also called e.g., power-to-gas/liquids/fuels), are fuels produced from hydrogen and carbon dioxide (CO2), using electricity as the major source of energy. Electrofuels is one potential group of fuels that could contribute to reduce the climate impact from shipping depending on type of CO2 and electricity mix (preferable non-fossil). Hydrogen, if used as a fuel itself and not as feed-stock for an electrofuel, obviously has a lower production cost compared to electrofuels (since electrofuels are produced from hydrogen). Hydrogen is preferably used in fuel cells (FCs), which have a higher conversion efficiency but also a higher cost compared to combustion engines. Electrofuels, in this study electro-diesel, has the advantage that it can be used in conventional combustion engines (ICEs). On annual basis the share “fuel cost” would be higher compared to the share “ship cost” the more the ship is used per year. The aim of this study is to analyze the following two questions (1) would the lower cost for ICEs, compared to FCc compensate for the higher fuel production cost of electrofuels? and (2) is there a breaking point where the total cost would shift between the two concepts electro-diesel in ICE vs hydrogen in FC? The cost comparisons are made for generalized types of vessels (i.e., short sea, deep sea and container). Results show that electro-diesel in ICEs can be competitive, over hydrogen in FCs, when vessels operate less than 150 days per year, whereas hydrogen has advantages when vessels are used more days per year. Container seems to be the category showing the most positive results on electro-diesel.