Diesel vs Electric Engine

[Dockhead]

Originally Posted by valhalla360

. . The problem is the weekend racers who just use the motor to get in and out of the harbor, use hardly any fuel, so the benefits are negligible.. . .

I don't think fuel saving is the main issue.


A simple plug-in electric propulsion system for a light day sailer or racing boat is surely cheaper than an inboard diesel. And lighter. I think that actually does sound like a good use case.


Another good use case might be an ultra minimalist long distance cruiser on a really small boat, who really doesn't motor except to get in and out of harbor. Now that's a case where solar can actually do something useful for propulsion. Like Pardeys plus a harbor engine.





But for normal cruising, I certainly agree with you. As for myself, I just motored three days and nights (three days and nights straight! I certainly owe my Yanmar a beer) from Greenland to Iceland during a dead calm -- a really dead dead calm, or very light contrary breezes, which is often the only weather window between shrieking gales you get up in these latitudes. A big tank of diesel fuel is really the only feasible way to do that at this stage of development of the technology.

[valhalla360]

Originally Posted by Marcin2000

If u ask me. Electric motors are much better than diesel engines. Why? Run only on diesel engines and for example ur diesel tank is empty over 200NM but electric engine need eletricity so u need to have a generator. If u run your generator to provide power for the electric engine u can sail for example 500NM before u fuel tank run out of diesel. And u can charge u batteries with solar panels wind generator hydrogenerator of panel on the sails itself

Run the numbers for us on how burning diesel in the generator results in 500nm range compared to 200nm range just using the diesel to directly power the prop.

[Adelie]

Originally Posted by valhalla360

Run the numbers for us on how burning diesel in the generator results in 500nm range compared to 200nm range just using the diesel to directly power the prop.

Hey if the generator pushes the boat at 2kt vs a dedicated engine pushing the boat at hull speed (6.5 kt) I could see that disparity in range.

But then you’re comparing apples to oranges.

[skipmac]

Originally Posted by hamburking

And don't forget that electric engines are not only almost silent, but need almost zero maintenance. All good arguments for electric.

Almost zero maintenance? Over the years I have repaired or replaced dozens of electric motors. Starter motors, bilge pump motors, autopilot motors, dive scooter motors, and a few more that I don't even recall. Then there's the HV controller and charging system. Maybe low maintenance but certainly some plus potential for repairs.

[Marcin2000]

I sold the 2 diesel Volvo Penta engines from my Privilege 5 Catamaran and bought Onan Diesel Generator 65KW to provide enought power for all stuff on the boat and for the electric propulsion. I have instaled 10 solar panels 150KW / Electic Energy D400 wind turbine and ny main sail have 8 flexible panels from Solar Cloth System. I bought 2 OceanVolt Servoprop electric propulsion motor (but need to install this on my boat - no time yet) which can make electricity when sailing (hydrogeneration). With all this and with fully recharged batteries i will need to run my generator only once a i dont know :-). I hope that all this stuff will keep the balance between input and output on the good side. That means I make 10KW and use maybe 8kw with cruise speed 5-7knots. That mean my batteries will always be fully charged.

[a64pilot]

I’d say it’s safe to assume with a 65,000 W generator, your batteries will be fully charged

It would appear that if it’s not loaded very hard that a 65 KW generator will burn (only) about 4 gls and hour. I would assume though that your use will have it at 3 gls an hour or maybe a little less?
https://www.dieselserviceandsupply.c...nsumption.aspx

[Chotu]

That is also about a 3500lb generator. Where, on a privilege Catamaran was this installed to keep the trim?