Aurora Botnia battery retrofit countdown

Wasaline is undertaking the largest battery retrofit project to date on its hybrid electric ropax ferry Aurora Botnia.

The project will see the marine battery specialist AYK Energy install a 10.4-MWh battery on Aurora Botnia, which operates a daily service between Finland and Sweden.

Built in 2021, Aurora Botnia presently operates on dual-fuel engines and 2.2-MWh batteries. The upgrade – to a combined battery system nearly six times more powerful – is expected to slash fossil energy use by around 10,000 MWh annually, cutting emissions by nearly a quarter each year.

Wasaline managing director Peter Ståhlberg explains the background to the project. “We started to investigate a retrofit of one engine with e-methanol. But it was impossible today to get a business case for it because we don’t know the price or availability. Production of methanol that was planned in the area [Sweden] is postponed. Therefore, the wake-to-well journey would be so big that the methanol would not be so green once we got it to the tank.”

It was through this study Wasaline found deploying batteries would provide the best payback – and it was a sidetrack to focus on e-methanol.

“We have a steady price for electricity, so we looked at technical studies and the business case for the batteries,” Mr Ståhlberg says.

The study found emissions would be cut by 23% by retrofitting larger batteries, leading to 23% less use of fossil energy.

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