Comparing diesel vrs electric propulsion(DIY/Production) in terms of resell value

[ranchero76]

It seems that many people misunderstand the idea. It's not just electric motor(s) and batteries. It MUST be complete system, only then it will make sense.
At current state of technology it CAN NOT be strictly electrical (considering it should be somewhat affordable). So genset is a must. However, correct setup will work in most situations without turning genset on.
For correct setup all you need - adequate solar, wind and battery power.
I would say - at least 2kW of solar power (6-8 panels 325W each), couple good wind generators, and big bank of hi capacity batteries. Yes, this setup most likely fits catamaran, not monohull. But than you can have TOTALLY FREE power for everything on boat, including stove, watermaker etc.etc., and STILL have excess power to use it when there's not enough wind for sailing. Also free! Everyday. No, you can't run electric motors for 24 hrs off batteries. But if you WILL need power for extended period of time (to get out of wrong places), just start genset, which is still by far more efficient than diesel drives. Yes, electric motors less powerful than diesel drives, but many videos show, that electric motors easily can drive boat at hull speed. How much faster you can do on diesel drive, and how much fuel you will burn?

[valhalla360]

Originally Posted by ranchero76

It seems that many people misunderstand the idea. It's not just electric motor(s) and batteries. It MUST be complete system, only then it will make sense.
At current state of technology it CAN NOT be strictly electrical (considering it should be somewhat affordable). So genset is a must. However, correct setup will work in most situations without turning genset on.
For correct setup all you need - adequate solar, wind and battery power.
I would say - at least 2kW of solar power (6-8 panels 325W each), couple good wind generators, and big bank of hi capacity batteries. Yes, this setup most likely fits catamaran, not monohull. But than you can have TOTALLY FREE power for everything on boat, including stove, watermaker etc.etc., and STILL have excess power to use it when there's not enough wind for sailing. Also free! Everyday. No, you can't run electric motors for 24 hrs off batteries. But if you WILL need power for extended period of time (to get out of wrong places), just start genset, which is still by far more efficient than diesel drives. Yes, electric motors less powerful than diesel drives, but many videos show, that electric motors easily can drive boat at hull speed. How much faster you can do on diesel drive, and how much fuel you will burn?

The problem is 2000watts is going to put the equivalent of about 2.6hp for maybe 5hrs per day (assuming nice sunny days...less on overcast days). After taking into account conversion losses putting it into the batteries and taking it out, you are probably down around 2hp for 5hrs. A small cat might have a pair of 20hp engines but you don't typically run at full throttle. Let's be generous and say they are running at half power (10hp each, 20 total)...

You now have enough power for a 1/2hr at cruise speed. The end result is anything more than just getting in and out of the harbor will require the generator to kick in at which point it is simpler and more efficient to just go with a conventional diesel drivetrain.

You need the same HP to maintain full cruise speed. There is nothing magical about electric HP vs diesel HP. Electric torque is generally greater from a standstill compared to equivilent diesel HP but unless you are doing drag races, it's not of much value.

[ranchero76]

You'd better check some videos. Here man says 4.5kW is more than enough in real life for Lagoon 410.

https://www.youtube.com/watch?v=1u267wy-d5A

So if there will be 20kWh battery bank (initially full), plus let say at 75% of 2kW solar 6-7 hours that's 1.5x6=9kWh, plus 2 wind generators will bring something. It looks like there's at least 30+ kWh of energy available. Few hours of cruising at 4.5kW, plus free energy for boat needs. O, yes, there's some wind energy from wind generators at night too, to charge the batteries. If there's wind, batteries will be charging from wind generators and regeneration mode of electric motors. And tomorrow will be free energy again. And if extended cruising needed, there's genset at 1L/hr. O, yes, and motors don't have to be 4.5kW. They should be at least 20-30kW. Use 4.5 kW for regular cruising. Or use all power (genset on) for these special situations (hopefully weather reports will help avoid them!).

[w1651]

Ranchero great post and I saw that video as I considered electric. There are a lot of videos on electric drives of all makes and models. Some noisey some not so much.
I went DIY electric motor and kit. It was much less then 7000 USD for the entire install. It's a high efficiency motor with high efficiency controller and systems.
The only regret I have is the electric is lighter then the original engine and transmission and that is with the batteries close to it. So I am going to change the old stainless tank to water and add a water tank to compensate.

[Terra Nova]

Unsubscribed.

[valhalla360]

Originally Posted by ranchero76

You'd better check some videos. Here man says 4.5kW is more than enough in real life for Lagoon 410.

So if there will be 20kWh battery bank (initially full), plus let say at 75% of 2kW solar 6-7 hours that's 1.5x6=9kWh, plus 2 wind generators will bring something. It looks like there's at least 30+ kWh of energy available. Few hours of cruising at 4.5kW, plus free energy for boat needs. O, yes, there's some wind energy from wind generators at night too, to charge the batteries. If there's wind, batteries will be charging from wind generators and regeneration mode of electric motors. And tomorrow will be free energy again. And if extended cruising needed, there's genset at 1L/hr. O, yes, and motors don't have to be 4.5kW. They should be at least 20-30kW. Use 4.5 kW for regular cruising. Or use all power (genset on) for these special situations (hopefully weather reports will help avoid them!).

Sure if you have boat with a normal cruise speed of say 7.5kts under power and limit yourself to say 4kts, you can extend your range. You can do the same thing with the conventional diesel an see huge increases in range.

Wind generators while on the move are at best of minimal benefit. If you are going into the wind, you will spend extra power dragging the wind generator thru the headwind. If you are running with the wind, there is minimal apparent wind, so you don't get much of any boost. If the wind is in that rare ideal situation...it's probably perfect sailing conditions.

That huge and expensive 20kwh battery bank is only really 10kwh usable unless you want to replace it frequently. Even at 4.5kw, that's only a little over 2hrs run time. Yeah the 2kw of solar panels can extend that a bit but bump that up to a more desirable cruising speed and you are at least doubling the draw.

By the time you add a huge solar array, a huge battery bank, a couple wind generators, a backup diesel generator and all the pieces and parts to make it work...you could have repowered with conventional diesel, purchased 20yrs worth of fuel and maintenance and still pocket some coin.

If your motoring is limited to in and out of port, electric is very viable. If you actually need to cover distance under power, it's easily more expensive than diesel.

[ranchero76]

Wind generators not THAT powerful to create huge drag while sailing windward. And there are blades with variable pitch, or removable blades, if needed. When sailing downwind. most boats will go much slower then wind, so there's some wind left for wind generator. And at anchor wind generators will take all wind which out there. So the point is - wind generators are not useless.
Regarding "that huge battery bank" (and "these expensive hi-efficient solar panels" for that matter) Smart sailor already has most of needed power on the boat, even without electric motors!

This is taken from other thread:

"We have 1400Ah LiFePo battery and 1800W solar.

We do like to do dumb things:
- Like running the water heater (every day staring in March, less often before) as the batteries are full in early afternoon.
-At least once a week we run the water maker for 5 hours straight (Spectra 400).
- Our $90 table top ice maker from Walmart runs every day for a few hours. But what do you care if the watermaker is on and the ice maker is running and there are still 30A+ going into the batteries.

We replace about 600Ah into our batteries every sunnay day. If the forecast is cloudy for a few days we use a little less, probably about 400Ah per day. We still easily get 200Ah in on a very bad rainy day so with over 1000Ah usable we can go 5 very gray conseccutive days without giving up any comfort.

We have been at anchor for the last 6 weeks, and at the same spot for six days now. So no charge at all from the engines lately. Anyway, you are lucky to get 30A going from the alternator into the batteries when under motor. And most of the time we sail."

(From here - http://www.cruisersforum.com/forums/...-156335-2.html
)
So all that smart sailor needs - just ADD few batteries to battery bank, few solar panels, wind generators and related electronics. Not to buy complete system!
But even the way it's set now, guy has excess FREE power everyday which he could burn, if he would have electric motors.

Regarding "That huge and expensive 20kwh battery bank is only really 10kwh usable unless you want to replace it frequently."

This myth also was busted many times already - modern batteries will allow much-much deeper discharge without any harm to them.

And I'd like to repeat - this setup will not turn sailing boat into power boat with free power. But sailors do sail most of the time, am I correct? And it's not uncommon that if there's no wind, people just wait few days, not motoring - to save fuel, which is not cheap nowadays. So even moving few hours per day on 4.5kW of power would be beneficial.

Also, when you guys calculating cost of having diesel motors, please calculate ALL associated costs. Diesel fuel, repairs, maintenance (oil, filters, belts...Don't forget - you still need solar panels and good battery bank to run boat devices and appliances, otherwise you'll burn way more fuel in genset.

[ranchero76]

Originally Posted by w1651

Ranchero great post and I saw that video as I considered electric. There are a lot of videos on electric drives of all makes and models. Some noisey some not so much.
I went DIY electric motor and kit. It was much less then 7000 USD for the entire install. It's a high efficiency motor with high efficiency controller and systems.
The only regret I have is the electric is lighter then the original engine and transmission and that is with the batteries close to it. So I am going to change the old stainless tank to water and add a water tank to compensate.

I think we should start thread, where all information about successful electric conversions will be collected. With prices, numbers, equipment used and result achieved.

[uncle stinkybob]

OceanPlanet Energy-Marine Energy Storage, Solar Power, Management

Interesting stuff here.

[ranchero76]

There are few places selling parts, complete setup or offering conversion. But only company which will offer affordable and smart solution, will win. So far most offered complete solutions are ridiculously overpriced. 1/2 (or more!!!) price of Tesla for two elerctric motors and electronic module for them? Looks like these companies just enjoy ripping people off, not making business. Therefore for now it's mostly for talented do-it-yourselfers (or for these with very deep pockets). It would be great if do-it-yourselfers would share their experience with others.

[skipmac]

Originally Posted by ranchero76

There are few places selling parts, complete setup or offering conversion. But only company which will offer affordable and smart solution, will win. So far most offered complete solutions are ridiculously overpriced. 1/2 (or more!!!) price of Tesla for two elerctric motors and electronic module for them? Looks like these companies just enjoy ripping people off, not making business. Therefore for now it's mostly for talented do-it-yourselfers (or for these with very deep pockets). It would be great if do-it-yourselfers would share their experience with others.

I'll second this. The prices charged by all the marine electric motor suppliers I've seen are completely outrageous.

[ranchero76]

And for these who interested in hybride - best of both worlds - it can be done too.
Here's guy connected 1.2L VW TDI engine to Honda Insight Hybrid system and made it work as factory:
1.2L TDI Honda Insight Build Completed - Insight Central: Honda Insight Forum

Here's video:

https://www.youtube.com/watch?v=4gQRbuZoVzM

It can be reprogrammed for boat needs (always use electric motor when is enough power, and run diesel otherwise). And yes, marinising stuff for TDI engine also exist (at least for 1.9L TDI ALH motor - one of the best engines in terms of possible tuning to any desired power (up to 200hp and even more), cheap parts, etc.). So for bigger cat (let say, 50ft+) this is probably the best solution.
And here's some more in case someone interested:
https://forums.tdiclub.com/showthread.php?t=253045