Candela P-12 achieves longest sea voyage by electric passenger ship

Candela P-12 on the Oslofjord, racing one of the traditional electric vessels already in operation in Oslo’s capital. Source | Candela

To demonstrate how hydrofoil technology has overcome short, fixed routes and dependence on costly, purpose-built charging infrastructure, Candela (Stockholm, Sweden) has completed a record-breaking voyage from Sweden’s west coast to Norway’s capital, Oslo, via the Candela P-12 Shuttle.

The 160-nautical-mile journey was the the longest ever by an electric passenger ship, Candela reports. Already proven in Stockholm’s public transport system, Candela P-12 holds the record as the fastest electric passenger vessel in operation, with a service speed of 25 knots, and has exceeded 30 knots during trials, with a range of up to 40 nautical miles at cruising speed on a single charge.

The P-12 Shuttle features carbon fiber/epoxy wings, hull, deck, inner structures, foil struts and rudder built via resin infusion (read “...composite hydrofoils to enable “world’s fastest” electric ferry”). Beneath its hull, computer-controlled submerged wings lift the vessel above the water at speeds exceeding 20 knots, reducing energy consumption by around 80% compared to conventional vessels and enabling long-distance travel at high speed.

This latest mission was to reach Oslo, where several electric high-speed ferries are already in service. The contrast between these conventional electric vessels and Candela P-12 is striking. Oslo’s fastest electric passenger ferry, m/s Baronen, operates a fixed 10-nautical-mile route and relies on swapping a deck-mounted battery container with several megawatt-hours of capacity at the end of each trip. The automated battery-swapping system alone has cost hundreds of millions of Norwegian kroner. While several swap stations have been completed, the system has faced delays and cost overruns, and deployment of additional stations has been delayed, limiting route flexibility.

By contrast, Candela P-12’s efficiency allows it to charge from standard, easily deployable automotive DC fast chargers. During the journey to Oslo, the vessel charged using a portable 360-kilowatt Skagerak Energi Move DC charger connected to a mobile battery system, towed behind a Ford F-150 Lightning electric pickup.

“Charging infrastructure is the hidden cost of electrifying conventional vessels,” says Gabriele De Mattia, project engineer at Candela and lead engineer for the voyage. “In many cases, building megawatt-scale chargers — especially where the grid is weak or undeveloped — can cost as much as the vessels themselves.”

The 160-nautical-mile journey was completed over 3 days, with demonstration and charging stops along the route. The Candela crew charged along Sweden’s existing DC fast-charging network using Aqua SuperPower stations, and where fixed chargers were unavailable, relied on the towable battery system provided by Skagerak Energi. The total electricity cost for the electric sea journey? Just over €200 (~$240).