Are Battery-Electric Vessels a Cost-Effective Maritime Solution?
Updated: Oct 3, 2020
In a nutshell, absolutely.
Apart from the fact that battery-powered engines are a much greener solution than their internal combustion counterparts, it turns out that running costs of electric vessels are significantly more financially viable. But let us talk about perspective for a moment.
We know that, initially, due to the use of more sophisticated technology and consequently higher production costs, battery-powered vessels are a more costly investment. However, if we introduce lifetime running costs to the equation, such as maintenance (including necessary battery replacement after 18 years – a calculation based on the operation profile of the investigated vessel and the life cycle of the chosen battery system) and fuel consumption, things start taking a massive turn.
Here is an instructive case study. A medium-sized river ferry operating on the river Main covers a daily route of 116 m multiple times at the speed of 2.7 kn. Diesel costs alone, for this type of vessel, are around 36.667 €/year. Replacing its diesel motor with an electric one would cut the fuel costs alone by more than 50% per year, leading to a 4 year ROI (return of investment).
If fuel costs were the only parameter by which we could compare these two types of vessels, battery-powered ones would turn out to be much more feasible in the long run. However, the story does not end there. Electric motors, generally, are much easier to live with, in terms of maintenance and servicing costs as well. Fewer moving part means less chance of something going wrong or needing regular replacement. Also, diesel motor vessels need a Particular Matter filter and Catalyst installed (for a 25 m ferry, we are talking between 50.000 and 60.000€ for installation), and, in some areas, they need to get regular exhaust treatment (between 1.500 and 2.000€/year for filters).
Finally, let us sum up the expenses.
An average lifetime of an electric vessel is around 30 years. In Germany, it is possible to get a loan with financing rates as low as 1% and create a comfortable financing situation for retrofitting an electric motor into your vessel. In summary, maintenance costs for diesel ships turn out to be 20 €/kW/year (Source: Manouchehrinia, B; Andersen, K.; Dong, Z; Hybrid and Pure Electric Propulsion Systems for A Short-Crossing Ferry), whereas they are only 13,25 €/kW/year(Source: Manouchehrinia, B; Andersen, K.; Dong, Z; Hybrid and Pure Electric Propulsion Systems for A Short-Crossing Ferry) for electric ones. This means, that over the course of those 30 years, you would be saving 6,75 €/kW/year!