July 13, 2022
X-Yachts of Denmark is the latest shipyard to offer electric propulsion on its sailing yachts with the introduction of the X4⁹E, an adapted version of their existing X4⁹ model.
X-Yachts joins builders like Arcona, Beneteau, Excess Catamarans, Elan, Salona, Fantail, Viator and others who either have electric propulsion as standard or now make it available as an option on some models.
“We didn’t want to be first movers on this area, but preferred to wait until technology and knowledge had matured properly”, says Kræn Nielsen, CEO of X-Yachts. “And I’m really happy to say that the time finally is right to present the first X-Yacht with electric propulsion.”
X-Yachts was founded in 1979 to design and build yachts for world class international offshore (IOR) racing. Success in that arena attracted the attention of the cruising market, where sailors were looking for some speed to go along with their cruising comfort.
In the past four decades the company has built nearly 60 designs, winning dozens of awards, and races along the way. It how has a range of nine performance cruisers.
“Finding the right project for our first boat with electric propulsion was crucial,” says X-Yachts Technical Manager John Morsing. “We worked in close cooperation with the owner of build number one, who knows our boats well and has a strong passion for green, silent boating.”
The client’s plans are “primarily to use it for long-distance cruising, but it has also been specified with performance sailing in mind and I intend to participate in challenges like Around Denmark Race and eventually, also the ARC Cross Atlantic.”
The propulsion system in the new X4⁹E is delivered by Finnish Oceanvolt, one of the world leaders in electric propulsion systems for yachts and a pioneer in regenerative systems, where the battery can be recharged when the boat is sailing under wind power.
“The boat is fairly big, 49 feet and weighs 12 tons” Morsing says, “so we have installed two Oceanvolt ServoProp SD10 engine pods, each 10 kW.” The twin motor solution serves two purposes: more power and higher safety through redundancy. Together they have the same torque as a 60hp diesel engine and in terms of top speed are equal to 30-40hp.
The Oceanvolt system runs on 48V, with the motors mounted on each side of the traditional engine compartment, below the aft cabin bunks. The former engine compartment has become a dedicated technical space, housing the battery bank, charger/inverter, BMS (Battery Management System) and controllers.
The LiFePo4 battery bank (Lithium Iron Phosphate, also known as LFP) has a capacity of 28,8 kWh. Range with pure electric power depends a lot on boat speed, wind and sea state, but Oceanvolt’s conservative estimate in calm conditions is 22,7 nautical miles at 5 knots.
The regeneration capabilities are a major benefit of the Oceanvolt system. The X4⁹E can produce up to 3,5 kW under sail (when sailing + 8 knots). This means that sailing for about eight hours will charge the batteries from empty to full.
While the regenerative system is ideally suited to most sailing uses, the X4⁹E can also be ordered with an 11 kW Fischer Panda diesel generator capable of running the boat for as long as there is diesel on board. The X-Yachts website has an outline of different use cases outlining range and speed with different combinations of battery and diesel.
While there are still significant challenges in using electric propulsion for large planing boats, many sailing boats requiring mechanical power only occasionally are perfect candidates for an electric or hybrid system.
Most companies now offering the electric options say there is great interest from clients. In fact, Fantail reports that the great majority of Tartan Fantail buyers specify their new electric drive package. As oil prices go up and battery prices go down, expect more companies to provide electric motors as an option, and perhaps even the standard.
Jeff Butler is based in Toronto and is the Editor/Publisher of plugboats.com, the international website covering everything electric boats and boating. He is also President of the Electric Boat Association of Canada and is busy preparing to bring electric motor boat racing and exhibitions to Toronto Harbour in 2023 for the first Toronto Solar Boat Races.