Full Charge Ahead - The Candela C-8

An e-powered craft has just established a new 24-hour long-distance operating record. Gustav Hasselskog, Candela’s CEO and founder, tells PBR about the challenge and the technology that enabled it.

Swedish electric boat manufacturer Candela’s latest version of their C-8 foiling craft has set, according to its makers, a new e-boat distance record after having covered 420 nautical miles within a 24-hour period in the Stockholm archipelago (the previous record stood at 79 nautical miles). ‘The feat shows that fast electric waterborne transport over long distances is viable today, not in the distant future,’ said Gustav Hasselskog, Candela’s CEO and founder, who piloted the C-8 during the record attempt.

The vital elements

While conventional planing electric boats face challenges due to water friction, leading to shorter ranges, the C-8 uses hydrofoil technology, with wings slung under the hull, which Candela state reduces energy usage by as much as 80%. This results in a range two to three times greater than that of traditional electric boats. Moreover, the C-8 can be DC-charged thanks to Candela’s partnership with electric car company Polestar, who supply both batteries and charging for the C-8. Together, this makes extended journeys using battery power more feasible.

The Plug charger provided 135 kW continuous DC charging for Candela C-8, which is the first hydrofoiling powerboat that can be fast charged

The recent record run, which comprised a loop between Stockholm and the island of Tynningö, included DC charging after each lap and was enabled by Northvolt’s mobile battery storage system, Voltpack. Waiting on the dock stood a 281kWh Voltpack system and a Plug DC charger, which enabled rapid charging of the C-8’s battery. Taking into consideration the necessary charging breaks, the average speed during the 24-hour run was 17 knots.

He continued: ‘With a relatively modest investment, charging stations could be built to fully electrify marine transport in the Stockholm archipelago. For a few hundred million euros, a charging network covering Europe’s coastal passenger transports would become a reality.’

The route from Stavanger to Trondheim.

Lessons Learned

The record distance run offered several insights into what can be achieved with Candela’s electric foiling vessels and a network of DC charging stations:

The distance travelled in 24 hours equates to driving from Amsterdam to London and back – or between Trondheim and Stavanger.
The C-8 could have shuttled across the English Channel between Dover and Calais 20 times in 24 hours.
Travelling at an average speed of 17 knots including charging breaks, the C-8 could journey from Stockholm to Finland in 13 hours, outpacing the Finland ferry by three hours.
The C-8 running at full speed, i.e. 27 knots, most of the time consumed 685kWh during its journey. According to Candela, ‘the cost of the power amounted to approximately €110–120 worth of electricity. In contrast, a conventional petrol-powered boat would consume roughly 750 litres of gasoline, costing approximately €1400’.Candela conducted the record run in collaboration with both Northvolt and the charging station supplier Plug to showcase what future DC charging networks for boats could look like in archipelagos and remote coastal areas. ‘Instead of making heavy investments in upgrading the local grid, islands could deploy battery systems like Voltpack to ensure that there’s enough power available for fast charging,’ Hasselskog told PBR.

The Voltpack mobile battery storage system by Northvolt provided onshore power for the Plug DC charger.

Looking ahead

This autumn, Candela introduce their new passenger vessel, the 30-person Candela P-12 Shuttle. ‘This vessel can operate most of the world’s coastal waterways while offering a sustainable and much more cost-effective alternative to today’s fossil-fuelled waterborne traffic, which accounts for 3% of global GHG emissions. We don’t have to wait for tomorrow. We have the technology to shift towards sustainable marine transport now,’ Hasselskog stated boldly.

Electric Endurance Challenge

The circuit consisted of a 20-nautical mile loop between Frihamnen and the island of Tynningö. During the 24 hours, the C-8 charged for a total of 313 minutes and received 615kWh of electrical energy. Each charge took about 18 minutes, and the battery was charged from about 13% to 66% state of charge (SOC). The Candela C-8 had an average charging speed of about 118kW. The vessel maintained an average speed of slightly over 17 knots during the race, including charging breaks. While driving, the target speed was 27 knots.

About Candela

Candela are a Swedish boat and ship manufacturer that develops sustainable, high-performance electric boats. Through cutting-edge hydrofoil technology, Candela have pioneered electric boats with an impressive range and speed. For additional details, visit the company’s website at candela.com.