Thursday, July 2, 2020

Re: [Electric Boats] Electric conversion

 

The problem with making this kind of calculator for recreational boats is they are not typical used all that much.  

Electric cars are generally far superior to gas cars in total life time cost due almost entirely based on fuel cost savings.  Maintenance is also cheaper, but a much smaller part of the total value. 

If you buy an electric car that cost $40,000 (say a Model 3) Versus a $30,000 gas car, and you drive it 50,000 miles in 4 years. Much more then just the $10,000 dollar difference will be saved in fuel costs. It will cost you about 2000 a year in electric charging versus 8000 a year in gas purchase.  You can see the electric car will have massive cost saving over it's life time. Even if only keep 4 years, and the savings compounded every extra year you keep it, or extra mile driven. The Tesla would be a better value in just two years of use, and would have recovered its entire purchase price in 7 years. 

Now if you spend an extra $10,000 going electric for your boat, and only use the motor 52 times a year (once a weekend) how many centuries would it take to break even? 

Now saying all that, I cruise on my boat and have maybe put 2000 nautical miles total on my motor in the last 3 years. So I would say I am at the absolute upper end of miles put on an electric motor installation.  My boat with gas engines would use about 8 gph at 10 knots, so to travel the same 2000 nm It would have cost around $6000 dollars compared to maybe $200 dollars in electric cost for the same amount of travel at a slower speed, I average around 4 knots.  So it will take me over 6 years of full time cruising to recover that extra $10,000.  And again I think I am on the very upper end of the use case curve.

Electric makes tons of sense for a commercial boat that does 40 nm a day, it will break even at some point.  But a boat that is used a few times a year, can never really break even.  So for any hope of breaking even using electric for boating, you would need to put thousands of nautical miles on the boat a year. IE be a full time cruiser or very avid day boater. 

As a side note, from someone that has used the hell out of there electric boat, I don't think battery cost for electric boats are "THE" limiting factor, even if batteries doubled in energy storage for the same price it would not make much difference to there utility. However if solar panels doubled in efficiency to 40% that would be game changing.  A 10 kWh solar arrays is probably the minimum size array you would need to travel at 5 knots all day long. And not feel constrained (IE real people would be happy to boat like that) But the only boat currently capable of having an array that large are 55 foot catamarans In the million dollar price range. Just not an affordable boat for real people.  But if you could get the same size array at half the physical space, you are now talking about a 35 to 40 foot catamaran, a type of boat a large number of people could afford.   Electric recreational boating will take off if that happens.  Battery technology would need to be 5 or 6 times as cost effective to have the same utility.  





On Jul 2, 2020, at 6:11 PM, Colin Davis colin.a.davis@gmail.com [electricboats] <electricboats@yahoogroups.com> wrote:

  

I found this comment by John very intriguing:

"But the bottom line is that you have to do an electric conversion because you want an electric boat - not because it makes financial sense."

Is anyone aware of any 'calculators' or 'worksheets' that help determine the cost of electric conversion vs. a replacement engine? I know it's not a straightforward question, but I'm wondering if anyone has created any sort of 'step by step' tool to help folks make the comparison. Some quick searching shows some 'guides' like this:


But this still requires lots of number crunching by the individual. I'm thinking of something more like this, for boat conversions:


At some point (maybe still years from now, with better batteries, etc?) it seems like it might very much make financial sense (for _some_ situations, when considering Total Cost of Ownership, etc., etc.. Caveats apply). But for someone like James, it should would be nice to have a handy-dandy worksheet to fill out that could get him started.

On Thu, Jul 2, 2020 at 4:26 PM Gene gfusch@hotmail.com [electricboats] <electricboats@yahoogroups.com> wrote:
 

One may also wish to look at Elco's plug and cruise option as they have been making electric boats for over 120 years.  https://www.elcomotoryachts.com or https://www.elcomotoryachts.com/product-category/electric-inboards/
Electric Motor Calculator. Award-Winning Electric Motors. Electric Inboard Motors There is no better way. The award-winning Elco electric inboard motor system uses highly reliable AC induction motors that are powerful and simple to maintain, with a suggested service life of more than 50,000 hours.

© 2020 Elco Motor Yachts. All Rights Reserved. Sitemap. Home; Our Story. Our Story; Elco Classic Launches; Elco Galleries; Shop. Electric Outboard Motors

Gene


From: electricboats@yahoogroups.com <electricboats@yahoogroups.com> on behalf of Jesper Malmberg jesper.malmberg86@gmail.com [electricboats] <electricboats@yahoogroups.com>
Sent: Thursday, July 2, 2020 12:27 PM
To: electricboats@yahoogroups.com <electricboats@yahoogroups.com>
Subject: Re: [Electric Boats] Electric conversion
 
 
I'm in the middle of a conversion and if you have not already, take a look at the following.

Thunderstruck-ev.com, this is the cheapest and most DIY solution that I have found anyways, I believe their system is the cheapest out there, but not specifically built for marine use. I think it's also most suited for smaller boats. This is the route I'm going down on my 30 foot sailboat. 

Electroprop.com, basically the same parts in their system but as far as I can tell is a bit more custom for your boat.

Electric yacht.com, a more professional system intended for maritime use. It seems good but is about twice the price compared to the two above. 

Torqeedo.com, this is probably the most professional option I've seen. But it is very expensive.

Also for inspiration there are numerous YouTube channels out there. Learning the lines, sailing Uma and sailing Saoirse to name a few. 

Anyways, this is all just based on my research, and I agree with John, You do this because you want an electric boat, perhaps only for daysailing, it is not a replacement for a diesel. At lest not with today's batteries.... good luck! 

/Jesper 


On Thu, Jul 2, 2020, 10:37 oak oak_box@yahoo.com [electricboats] <electricboats@yahoogroups.com> wrote:
 
James,
Start by outlining what you want to do with the boat.

Will you only sail it with minimal aux power to get in and out of the marina?   Or do you want to be able to cruise for several hours with the sails down?

What speed are you comfortable with? How long will your trips be?

With that kind of insight, then an expert might be able to make some guesses on the type of motor that would be appropriate.

If you know the motor, and the range / speed you want to be able to go - then you can calculate the size of the battery bank.   Then you can start to get an idea of what the cost of an electric conversion will be.

Be prepared:   For that size boat, if you want any kind of significant range (and I'm only talking 2 hours or so....  plus a 3rd hour for margin) - the cost of a conversion will most likely exceed the cost of having the diesel replaced.

The advantage of going electric is that maintenance can be considerably less.  No oil changes.  Probably no impeller changes unless you go with a water cooled motor. You can get rid of a couple of holes in the boat!

But the bottom line is that you have to do an electric conversion because you want an electric boat - not because it makes financial sense.

Hope that helps some.

John

On Thursday, July 2, 2020, 12:02:40 PM CDT, financial@jamesschmidt.xyz [electricboats] <electricboats@yahoogroups.com> wrote:


 

I have  a 1971 CT 41 sailboat with a frozen 50 hp diesel engine.  My boat displaces 25700 lbs.  Where di I start?

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