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The work, which was financially supported by Swedish electric boat company Candela, was carried out by researchers at the Royal Institute of Technology in Stockholm.
Billed as the fastest and longest-range electric ferry to date, the Candela P-12 Shuttle will start sea trials in the Stockholm region next year.
The P-12's hydrofoils lift the boat’s hull out of the water once it reaches a certain speed, reducing its drag in the water and reducing energy consumption.
The Royal Institute team compared the 30-passenger craft with the city's diesel-powered vessels. In Sweden, domestic shipping emitted roughly 680,000 tonnes of carbon dioxide in 2020, more than trains, buses and domestic flights combined.
The analysis examined the different stages of a ship’s lifecycle – extraction of raw materials, manufacturing, and use, until it must be disposed of or recycled. Over a lifetime of 30 years, the study found that the carbon footprint of a P-12 Shuttle would be 97.5% lower than the compared diesel ships.
According to the authors, the study is the first to demonstrate the difference in environmental impact between electric hydrofoil ferries and traditional ferries.
“The combination of using hydrofoils and being powered by electricity is the main factor in lowering emissions. And since the Swedish electricity grid is almost free of carbon dioxide emissions, this type of ship has a clear advantage,” said Felix Glaunsinger, one of the authors.
The hydrofoils reduce energy consumption by 80% compared to conventional ships, the study found.
When the 30-knot P-12 starts sea trials, it will reportedly be the fastest electric ship in the world and also the fastest passenger vessel in the Stockholm public transport fleet. With a range of 60 nautical miles, it can cover the archipelago's longest routes.
Since the ‘flying ferry’ has less wake, the city has granted it exemption from speed limits, cutting travel times from 55 minutes to 25 minutes on the maiden route from the suburb of Ekerö to central Stockholm.
The study also found that the P-12 has a low carbon footprint from production compared to the diesel ferries examined, despite other electric vehicles such as cars often having a larger carbon footprint from production due to battery manufacture.
“Just like aircraft, our vessels are made to be as light as possible to maximize the number of passengers and performance. A welcome side effect is that we’re able to use smaller batteries and less raw material, which in turn means a lower negative climate impact,” said Erik Eklund, head of Candela's commercial vessels.
Worldwide, ships account for about 3% of global greenhouse gasses, comparable to the global aviation industry’s emissions. Emissions are expected to rise considerably in the coming years, despite the International Maritime Organisation’s ambition to cut ships’ carbon intensity by 40% by 2030.
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