The next time someone asks you about electric boat range, ask them if London to Amsterdam and back within 24 hours would do it for them? The hydrofoiling Candela C-8 just covered a distance equivalent to that, breaking the previous world record of the Voltari 260 for the longest distance driven by an electric boat in a day.
To be clear, the Voltari record was done on a single charge with the boat travelling at low speed, while the Candela record was set going close to top speed between Frihamnen (in Stockholm) and the island of Tynningö with charging each loop. One of the reasons for attempting the record was to show the viability of marine DC charging networks for coastal areas.
During the 24 hour run, the C-8 charged for a total of 313 minutes and received a total of 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 118kWh per hour and maintained an average travelling speed of slightly over 17 knots during the race, including charging breaks. While driving, the target speed was 27 knots.
“This feat shows that fast, electric waterborne transport over long distances is viable today, not a distant future” said Gustav Hasselskog, Candela’s CEO and founder, who piloted the C-8 during the record attempt.
Electric boat range achieved using 80% less energy
This is exactly what the Candela hydrofoiling technology was designed to achieve – electric boat range and speed comparable to a similar fossil fuel boat. The C-8 won the 2022 Gustave Trouvé Electric Boat Awards in the Up to 8 Meter/26 Feet category.
The company says that the C-8, running at the target 27 knots most of the time, consumed 685 kWh during its journey, costing about €110-120 (US$ 120-125) in electricity. In contrast, a conventional planing boat powered by gasoline/petrol boat would consume roughly 750 liters of fuel (200 US gallons), at a cost of €1400 / US$ 1500.
Conventional planing boats – fossil fuel or electric – have to use a lot of energy just to fight through water friction and maintain, while the C-8’s hydrofoil technology that enables the boat to ‘fly’ above the water reduces the energy required by 80%.
“Magic carpet ride”
I was able to take a ride in a C-8 earlier this year as a guest of Candela’s French dealer Sud Plaisance, and I can say that the feeling and experience is extraordinary. The boat rides through the water like a traditional craft, except much quieter, because of the electric motors. You can feel the waves and then, at 17 knots or so, it starts to rise out of the water. The feeling is very similar to a plane taking off from the runway, except that with a plane, after you leave the runway, there is still the turbulence of rising through the air at high speed.
With the Candela, it seems that…you just start floating above the water. What a feeling. I had read it compared to ‘a magic carpet ride’, and once you feel it, that description is accurate (although I have never been on a flying carpet!)
I have been in a hot air balloon, though, and I would compare it to that. We were flying above the water at 25 knots (46 kmh / 28 mph) with almost no sound of any motor…the hydrofoils keep you above any wave effect…it actually feels like you are going slower than before liftoff…it is silent and serene. Incredible.
High speed charging station fed by onshore battery
Polestar, the electric car company, is a Candela partner and supplies both the batteries and onboard charging technology for the C-8. For the record run the onshore charging system was a Voltpack mobile battery storage system from Northvolt coupled with a DC charging station from Norway’s Plug. The idea was to showcase how DC charging networks for boats could look in archipelagos and remote coastal areas.
On the dock in Frihamnen there was a 281 kWh Voltpack system and Plug DC charger. The boat was charged after each loop to Tynningö and back, about 40 Nm (≈ 45 mi/ 75km). In the photo below the white blocks behind the charging station are the Voltpacks.
The Voltpack is used because one of the challenges in remote or difficult-to-get-to areas like those in the Stockholm archipelago is the expense of installing electric infrastructure for high speed charging.
Instead of making heavy investments in upgrading the local grid, islands can deploy battery systems like Voltpack to ensure that there’s enough power available for fast charging. The grid charges the Voltpack over a number of hours at regular speed, and when a boat arrives, the Plug station charges the boat at high speed.
Setting the stage for coastal charging networks
The record distance run offered several insights about what can be achieved with Candela’s electric foiling vessels and a network of DC charging stations:
- The 483 mile distance traveled is roughly equivalent to driving from Amsterdam to London and back, Barcelona to Monaco (425 mi), Boston to Washington (440 mi) or San Francisco to San Diego (500 mi).
- The C-8 could have shuttled across the English Channel between Dover and Calais 20 times in 24 hours.
- Traveling 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 3 hours.
“With a relatively modest investment, charging stations could be built to fully electrify marine transport in the Stockholm archipelago” said Hasselskog “For a few hundred million euros, a charging network covering Europe’s coastal passenger transports would become a reality.”
This fall, Candela introduces its 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-fueled waterborne traffic, which accounts for 3% of global GHG emissions.
”We don’t have to wait for tomorrow” Hasselskog continues, “we have the technology to shift towards sustainable marine transport now.”