Tranquility has an electric heart

Our boat comes with an electric engine. It is an Electric Yacht system that was installed by one of the previous owners of the boat. It was a total surprise for me as the most common mean of auxiliary propulsion on sailboats, and the one I was used to, is marine diesel engine. This is what I expected to find and what I was looking for. A small good old diesel engine.

Diesel has a couple of good features: a high flash point that allows a relatively safe handling and a good energy density that provides satisfying motoring range with limited storage required. It’s not uncommon on a sailboat to turn on the engine if the wind shift to an undesired angle, if the batteries go down or to fight against tides and currents. And of course wind is not always blowing. These days, with the decreased costs and new tiny engines that fits everywhere, nearly all modern sailboats would qualify as motorsailers.

Every sailor has a story about a capricious diesel engine that needed some cajoling and improvised repairs. Oil and filters change, belts, starters, alternators, electric connections, water pumps are some of the most common maintenance issues that force crew to kneel and assume awkward postures to reach remote corners. Even assuming and registering that a little dose of fuzzy logic is always present diesel engine is far the most used and realiable marine propulsion. Service and parts are available worldwide and experienced cruisers know and share a lot of tricks.

But what about electric drive? After the initial surprise curiosity started to peep in. I remember Kate asking me that her desired boat would have an electric engine. That time was even before we met Tranquility and the answer from me it was “of course not! This is Sci-fi”. My experience so far has always been on diesel engines (including an overhaul and an installation of a brand new one) so my limited mindset suggested me that her idea was a profanity. Well it happened that we purchased a boat with an electric drive.

Electric propulsion has its pros and cons, like anything in this world. One of the pros is that you get rid of fuel and oil, fumes, noise and vibrations. That is extremely good if your engine sits in your living room, as it happens on our tiny boat. Electric propulsion is clean, and helps fighting seasickness that is amplified down below by fumes and miasmas.

The cons are its limited range and having to deal with a bit more complicated electric system. While the system is no rocket science if you are familiar with DC current, the range is the big limit, as batteries are still not the most efficient way to store energy. You need a big and heavy bank of batteries to get a 20nm range, that is nothing compared to what diesel engine and even an outboard can give you. Or you can resort to LiFePo4  (Lithium iron phosphate) batteries if you have the dough to pay its exorbitant price, but even with that budget your range will still be inferior compare to an internal combustion one. A cost wise installation of the “old technology” lead acid batteries, will give a 30ft boat around 15 nm range. The Electric propulsion adds new components to your electric system, and if any of these components fail, the whole system is useless.

The average sailor (assuming that such a thing exists) would find these cons very hard to overcome. There are two things that are keeping Internal Combustion Engines the favorable option for sailboat. One is that the technology for electric drive is not fully developed. This is true especially for batteries. All lead acid batteries provide about the same capacity/weight.  You need to go to LiFePO4 batteries to go lighter and have extended range due to a higher tolerance to discharge.  They are roughly 5x the cost of good AGM, (so likely well out of my budget!), but prices are coming down and renewable energy is quickly developing.

Another thing is the average sailor mentality. It is strictly related to our car driver mentality, so if I have to get there I will and when I want. It’s the reason why people get mad at traffic, it’s between them and their goal! It’s not a favourable day for sailing, well let’s go out anyway bobbing around with the engine. Would tacking upwind take too long to get there? Let’s pack the headsail and motor into the wind. Is the current too strong? No way I am giving up, let’s use any single HP why would I carry around this heavy and smelly piece of iron otherwise?

I am an average sailor myself. So why did I decide to keep the Electric Yacht?

I think that an Electric propulsion will make me a better sailor. Having a small range doesn’t mean to have no range at all. I would keep mooring and anchoring under power and will do it under sail just for fun or to impress friends. My first sail in my life was offshore and engineless and since then I had more than one diesel engine failure that forced me to do everything under sail. That made me a little bit skeptical about any propulsion system. Electric propulsion will make me plan my sailing better, considering currents and piloting hazards. If I am in trouble for some reason 10 nm is plenty of range to find refuge. Liveaboard will prevent the hurry of going out no matter the sea and wind conditions because that’s the only day I can go sailing.

There are so many reasons to chose an electric propulsion as auxiliary power on a sailboat, and one of my favourite is that Electric Drive is truly the present and the future of propulsion!