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I don't see any glaring issues. You seem to be reasonable about expected range and capability which is normally the major problem with these threads.

I would suggest getting a small 2kw honda generator for those times when you need to deliver the boat somewhere, but otherwise it looks reasonable.

 

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Point taken in regards to the dead air months. We'll just have to see how that works out after our first season in a pure electric.

I have a fair bit of experience with ICEs in general, less with diesels, but it could be a small crack in the fuel line somewhere that's leaking just enough to let it smell. $5 says I'll find it when I pull the engine out and it will be somewhere obscure and/or damn near impossible to get to.

In short, other than fuel supply, an electric system is superior in every single way. It's cheaper, easier to diagnose, more powerful pound for pound, the fuel is cheaper no matter what the source, there's no maintenance, etc. Once battery capacity or a small, portable high energy power source is developed, diesels are toast, save for "vintage" folks. I'd prefer to be on the leading edge than the trailing edge.

The major problem with electric conversions is the range. Make no mistake about it, there is no technology we have or is even in the pipeline that will make electric vessels capable of storing more than a few percent of the usable power available in fossil fuels.

The useful energy density of batteries just isn't anywhere close to that of fossil fuels. To get the same range under power, for every pound of diesel fuel you remove you need to add back fifty pounds of batteries. This very quickly hits a practical limit of just 1-2 gallons of diesel fuel.

The reason I said you seemed to be reasonable is that your plan assumes just motoring in and out of the harbor. Much more than just this is a very different question.

 

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Canuck,

You need to redo your consumption numbers. The correct comparison between a diesel burning .4gallons/hr is about 6.7kw, not 2 (the actual number is 18hp/gallon). This is why renewables for propulsion power just don't work. Moving a multi ton vessel around just burns more power than any reasonable renewable setup can produce.

This is why it's critical when considering an electric setup that usage patterns change. You have to accept that you will go slower, with less range, and have almost no reserve power. So long as you are realistic about this it is fine, but fudge these numbers and you will be greatly disappointed.


As an addendum, there is no battery technology on the market, or even in laboratories today that come close to resolving this dilemma. The best laboratory battery I know of has an energy density of about 5% that of diesel fuel. This would still only provide a fraction of the power available most boats consider minimal. At the rate battery technology is going a realistic timeframe is probably more like 50 years (absent a real breakthrough).