The number of “electrified” boats sold worldwide in 2022 is still very low (it accounts for probably less than 2% of an estimated fleet of 2,000 multihulls). Compare this figure with those from the automotive market: worldwide, the proportion of electric vehicles in overall sales (not counting hybrids) was 7.8% in 2021, rising to 12.9% in 2022, and even reaching as high as 16.1% in the first quarter of this year.
Up until now, electric drivetrains have been offered by smaller, pioneering shipyards, but they are now beginning to be a major feature among the big boatbuilders. As recently as last year, few customers opted for this new type of propulsion. Supposed complexity, low power, battery recharging, range, cost, reliability and after-sales service are all issues that raised many questions. A year seems to be all it has taken to the tide to turn for good: the realization that boating can be greener and more virtuous is now in the minds of almost all sailors. At the beginning of 2022, two out of ten prospective customers were asking about these alternative, environmentally-friendly motors. Since the boat shows of late last year, these figures have reversed: according to many manufacturers, eight out of ten boaters now systematically raise the subject with their dealer or agent. The choice of a less polluting engine is therefore gaining ground in our minds - both among buyers and those wishing to charter a multihull. Of course, there are still a few obstacles in the way, and many boaters, just like customers in the automotive industry, are still skeptical about the merits of the approach at the current stage of development of these new technologies, fearing a lack of performance and reliability from hybrid and/or electric drivetrains. Some prefer to wait and see, while a growing number of others are anticipating the call: for the latter, taking an active part in this evolution of our modes of boating is an eco-responsible step.
Variable-geometry legislation
Bans on CO2 emissions have long been in place on many inland waterways in countries including Germany, Austria and Switzerland. More recently, Switzerland, and also France and Italy, have adopted restrictions targeting internal combustion engines. Many sections of Europe’s inland waterway network are also affected, and boats operating there are encouraged - sometimes with subsidies for professional operators - to switch to electric motors. Marine waters such as Marseille’s calanques and certain Norwegian fjords are now reserved for clean propulsion. No doubt many countries around the world will follow suit. The message is clear enough to encourage boating industry professionals to go electric in the first place. In fact, e-motor manufacturers are reporting (for the time being) far more installations and replacements for professional boats than for private craft. For Jeremy Benichou of Torqeedo France, changes in legislation in favor of electric power have had a triggering effect. No fewer than 1,500 small workboats have switched to this type of propulsion in the last two years. As far as we’re aware, there isn’t anywhere where leisure vessels benefit from subsidies.
Biofuels: an intermediate step?
However, the bans on greenhouse gas emissions do not apply to offshore boating. It’s reasonable to assume that the areas where CO2 emissions are regulated will extend to many coastal areas in the longer or shorter term. This could mean an intermediate stage, with the possibility of releasing exhaust gases that are less harmful to the atmosphere. Biofuels represent the future of this hypothesis, as they enable an evolutionary change of technology, using the current achievements of internal combustion engines. That being said, we must be careful not to fight the wrong battle: palm- or soy-based biodiesel emits up to three times more CO2 than crude-oil based fuels! Bioethanol fuels emit on average half as much, with the exception of barley, which is still higher than diesel. The most advanced, based on short-cycle plants (perennials or forestry residues) have a very low balance, even negative in some cases. These fuels could therefore represent a solution for reducing emissions.
Betting on hydrogen
Hydrogen is undoubtedly the least polluting solution, and - in theory – will make it possible to switch to all-electric technology. In practice, however, a generator and a tankful of diesel are still the safest option. In this zero-emissions niche, Fountaine Pajot have taken the lead, designing with EODev the first leisure catamaran to run on electric hydrogen. Their Samana 59 prototype has been fitted with two tanks containing 7.5 kg (16.5 lb) of hydrogen pressurized to 350 bar (5,076 psi), which feed the famous REXH2 fuel cell, producing 70 kW to recharge the 63-kWh battery. This set-up allows the yacht to remain at anchor for forty hours, and to “motor” at 5 knots for 10 hours without making any noise and with the only emission being water. Initial trials are underway (see our article They’re innovating!). Sunreef Yachts, who launched their 80 Eco model fitted with photovoltaic cells last year, has just announced a hydrogen version of this particular model. We can only hope that other manufacturers will be following in the wake of these two trailblazers. There remains the problem of hydrogen refilling stations, obviously non-existent in ports. Is rapid development like that of electric car recharging stations conceivable?
Engine and equipment manufacturers facing the challenge of clean boating
All over the world, manufacturers are making tangible efforts to offer Forever Green solutions. Most boat shows now offer dedicated areas for these players, but electric power now extends far beyond the boat show booths and is now available on most Fountaine Pajot models. In addition to the hydrogen fuel cell developed by EODev mentioned earlier, there is also INOCEL’s hydrogen fuel cell, which promises 300 kW. EFOY, meanwhile, offers a battery powered by methanol. As for e-motor manufacturers, Oceanvolt, EVO and Bellmarine are now backing the frontrunner in the race, Torqeedo. Historic generator manufacturers, such as Fischer Panda, have also embarked on the electric adventure. For their part, traditional engine manufacturers could be accused of being “late to the party...”. In reality, they are faced with very significant challenges in the land transport sector, which justifies the fact that the marine industry is treated as a secondary concern. Their strategy is logically geared towards electric hybridization and/or the use of new fuels. One of the heavyweights in the sector, Yanmar, is focusing its energy transition on electric hybridization and energy optimization with low-carbon fuels such as HVO (hydro- treated vegetable oil) and synthetic fuels. Cummins are also interested in new, less polluting fuels. Volvo are following the same approach and have already fitted an electric motor to their D4 and D6 DPI Aquamatic gensets, as well as to the larger IPS 500 to 1200 motors. A number of accessory manufacturers, such as E-motion and Transfluid, offer to adapt existing engines by coupling an electric motor to them, with the aim of electrifying second-hand multihulls or one-offs. This “parallel” hybrid assembly technology enables a vessel to operate emissions- free in harbor situations and protected coastal areas at boatspeeds of between 5 and 10 knots. Once offshore, the multihull switches back to its internal combustion engines to achieve higher speeds and, more importantly, greater range. This differs from the “production” configuration, in which the purely electric motor is hybridized with the internal combustion engine-based generator (or other solution such as fuel cells), which supplies the energy required by the batteries to propel the multihull - see Multihulls Match in this issue. In the example of a dayboat that returns to port in the evening and is able to recharge the batteries overnight, or a vessel equipped with a very large surface area of solar panels and/or a hydrogen fuel cell, we’re talking about 100% electric installations. Multihulls equipped in this way emit no (or almost no) greenhouse gases.
What electrical installation method should you choose?
The question of size and type of multihull, and of course its intended program, is at the heart of these technological choices. A lightweight dayboat that doesn’t stray far from shore, such as the Bagou 8.0 (see test in MW171) or the Orphie 29 (tested in MW183), will be quite content with a series installation (outboard, pod or inboard). The large battery bank attached to a powerful motor can be recharged overnight. Bigger models such as the Pinball (tested in MW181) are less sensitive to load weight but require high power and a comfortable range. These multihulls are more likely to opt for “parallel” mounting. The Bénéteau Group is banking on this technology for its long-range powerboats, but with caution due to the large production volumes that become rapidly involved. The precedent set by the Lagoon 420 is still fresh in everyone’s mind. A hundred or so catamarans built in 2008 with electric motors fitted as standard were repowered with internal combustion engines in 2010 at the manufacturer’s expense. A test campaign has been launched in partnership with Volvo, based on a Jeanneau NC37 monohull equipped with a Volvo Penta D4-320 DPI Aquamatic. This hybrid powertrain will offer three hours of electric running at 8-9 knots. Once validated, this technology could well suit a Prestige M48 using the same power (times two, of course) with an adapted transmission. Volvo claims that a 40% reduction in emissions is possible over a season’s use.
This could be an interesting argument for multiyachts, which are already more fuel-efficient than their single-hulled colleagues. On sailing multihulls, on the other hand, “series” installation seems unavoidable, unless the engines are fitted in the center of the hulls, as is the case on the Gunboat 68 or HH66. Aboard the Aura 51 Smart Electric (tested in MW186), the Excess 15 prototype, the ITA 14.99 and the Outremer 4.Zero (tested in MW175), “series” installation was chosen, as it offers the possibility of distributing the weight in a fore-and-aft direction. The electric motor doesn’t weigh much in the aft compartment, and the batteries can be installed further forward, under a berth or central passageway. Motor speed does not need to be high. Moreover, engines are not the only means of propulsion, and under sail there is the possibility, thanks to hydrogeneration, of producing your own electricity.
Unprecedented collaborations
In a state of constant technological evolution, the “green” drivetrain requires extensive testing before it can be safely offered to customers. These development phases give rise to unprecedented industrial and commercial synergies. Because electric motors need a lot of electricity, energy production and storage are of prime importance. Management interfaces, meanwhile, are complex to develop – and it’s a chain that needs to be mastered from start to finish. Cummins has bought out Meritor and partnered with Editron, a division of Danfoss Power Solutions, to develop marine hybrid solutions. Torqeedo is working with Proton Motor on the Ma-Hy-Hy (marine-hydrogen-hybrid) project, an integrated electric motor and fuel cell power system with outputs ranging from 30 to 120 kW. Equally important is the delivery of energy to the multihulls. Silent Yachts is launching its second eco-marina project in Fiji, giving a means of recharging batteries with solar panels installed ashore.
In the same spirit, Fountaine Pajot, who point out that 80% of the carbon footprint is linked to boat use according to a study conducted by the GHG Protocol (a standard for accounting for greenhouse gases), is studying with charter company TradeWinds the possibility of producing green hydrogen from home ports also using solar panels. Other major charter companies such as Dream Yacht Worldwide have just ordered ten Aura 51 and Elba 45 Smart Electric yachts. The Click & Boat booking platform is also offering its users a range of electric multihulls (Fountaine Pajot and Orphie 29 catamarans).
Brands that are 100% Forever Green
The challenge of clean boating is now attracting a great deal of interest. Builders including Silent Yachts, Windelo and VAAN Yachts all offer electric motors. More recently, the German brand Alva Yachts presented a range of electric motor catamarans over 70 feet long. The very young French company Whisper Yachts has just unveiled plans for an electric-solar motoryacht based on a 50-foot luxury catamaran. Three orders have already been received for this powercat driven by a pair of 100-kW Torqeedo Deep Blue motors. The Whisper 50, with 240 kWh of batteries and 320 square feet (30 m²) of solar panels, boasts unlimited range at 5-6 knots.
These smaller companies, presenting products at the cutting edge of tomorrow’s green boating industry, have very different constraints from those of brands that have been established for decades. For the time being, with the notable exception of Fountaine Pajot, the former serve as hares for the latter to chase, and who must offer a consumer product that is technologically more affordable - and perfectly mature.
What if a player were to emerge from nowhere, like Tesla in the automotive market?
