RANGE ANXIETY
Just as with electric cars, whenever anyone whose vessel is equipped with a conventional diesel falls into a conversation about electric propulsion for boats, the first question is almost always, ‘How far will it go on a charge?’
Well, the answer I’m afraid is simply, ‘It depends.’ How far do you want it to go? Are you willing to toddle along at four knots, or do you want to charge around from port to port like a Greek charter yacht?
I get that it’s not for everyone and, being a mature seafarer myself, I dread to think about losing all power whilst halfway through the Portland Race in the dark. But as with pretty much anything to do with navigating a vessel, you just need to plan things out carefully in advance.
There are those that say having a finite source of auxiliary propulsion teaches you to sail better, which in many ways is true. The introduction of the powerful modern marine engine has made us all lazy with our tidal planning, knowing, as we do, that you can always resort to the donk to get you home if the log drops below 4 knots or that extra pint in the pub has made you late for the tidal gate.
So, let’s look at some facts. The typical electric propulsion system for a 10m, 6-tonne cruising yacht will usually be designed to provide around five to six hours of gentle cruising in fairly neutral currents at around 4 knots, or maybe 10 hours of motorsailing, before requiring a charge.
Unlike a car, however, a boat can have solar panels on its deck, coachroof and arch, that can extend this range by another couple of hours, maybe, in the summer.
And then there’s the possibility of regeneration.