THE BIG SWITCH
GOING ELECTRIC
The 2023 introduction of the Contest 50CS and Contest 49CS marks a genuinely significant step into optional electric propulsion. Very much more than a nod to sustainability and silent operation, this system simultaneously uniquely brings massively extended range for true long-distance voyaging.
With eyes on reducing life-cycle emissions and impact on Planet Earth, it’s no secret that electric propulsion is part of the future brief for any and every yacht builder and owner. It has to be so; such moves toward sustainability are legislated. The issue, though, has been how and when to make the switch. Most constructors going electric follow the original and inherently limiting hybrid principle. The approach Contest has taken, partnering with Torqeedo, is a different and technically very much more advanced solution. Contest’s Senior Technical Engineer Robert Vijselaar explains, “With the early, original hybrid approach, the diesel main engine remains as primary drive unit but with an additional, parallel electric motor. Propulsion can be drawn from the diesel engine alone, the electric motor alone, or from both together in parallel.
But the diesel engine remains the drive train’s main power source; the electric drive is secondary and generally has limited power. It’s only a partial solution. The Torqeedo system is a very different hybrid.” INCREASED EFFICIENCY In this, a single electric motor alone drives the propeller. There is no conventional main engine, just a diesel generator, a part of the recharging array. There is much increased efficiency in this. A diesel drive unit operates under varying heavy load and the engine is optimised for that. Generators are optimised for lower loads, lower revolutions, and consistency in electrical output. So, beneficially, with a generator, fuel consumption reduces. And with no ‘engine’, machinery and tankage weights then reduce, as do wear and tear and maintenance, which all leads to better delivery, better longevity, better security.
Also differently, this system’s 20kW DC Fischer Panda generator outputs its 360 volts straight to the high voltage battery – super-efficiently with no chargers between – and/or straight to the electric motor also. Favourably, this means the yacht can be propelled directly via the generator without discharging the batteries, while even simultaneously charging the batteries.
And the battery set packs a mighty 40kWh standard, and optionally 80kWh, for long extended available time in silent all-electric operation, be that on passage or swinging at anchor in a quiet, starlit cove while still running onboard hotel services.
RUNNING THE NUMBERS Contributing also to continual renewal of onboard energy there’s a regenerating propeller, one or two 600W Watt&Sea hydro generators – neatly integrated into the yacht’s structure between keel and rudder – and Solbain photovoltaic solar panels in the superstructure. These all then directly replenish the 24 volt DC lithium service batteries which draw their main charge from the high voltage battery pack to keep powering everything from winches and furlers to lights, air conditioning and coffeemaker. Which means all things electrical on board and potentially enabling real distant bluewater sailing. That last point is really significant, as Robert comments, “Range never gets asked about with conventional diesel drive yachts, just tank size. But mention electric drive and it’s one of the very first questions.
So, looking into this we comprehensively ran the numbers across all conditions taking into consideration resistances of hull and rig, weather, wind, sea state, etc. The results impressed, to the extent that with care and in the right circumstances, our electrically powered cruising can theoretically be endless. It’s a win-win!” So, ocean crossing running electrics in silence and making great cost savings, this is novel. it's true, yes, on the longer voyages in lighter conditions use of the heavier consumers like washing machine and air conditioning may be constrained, but there is no doubting the opening of enormous new opportunity. It’s all about how you to choose to sail, to use your boat, your lifestyle. And for those exploring more local waters, such constraints completely disappear. There’s no need to ask … range easily exceeds requirement!
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