Does a genset still make sense?

[Simi 60]

Originally Posted by NorthCoastJoe

I got a Honda generator that weighs less than 50 pounds, puts out 2200 watts, for $1200. Simple easy to take care of and no stress on my diesel.

Ok on a small battery bank but they only do around 50amps @ 24v - our solar does more at times.

Our charger can put out 120amps @ 24v, so Honda not up for the task.

[Pete7]

Originally Posted by sailingharry

I think it's worse than that Jedi. I have 270A mounted on my 50 horse Yanmar, and I keep trying to ignore the negative vibes from the internet about breaking my crankshaft off. I'm not sure that a 20 horse diesel would be at all happy with a 400a alternator!

Beta do it for 20hp engines upwards, all be it at a price. 5kW at 48v would be nice. However, you could buy a lot of Honda 2200 on a world tour and still be up.

https://betamarine.co.uk/he-hybrid-propulsion/

[sailingharry]

Originally Posted by Pete7

Beta do it for 20hp engines upwards, all be it at a price. 5kW at 48v would be nice. However, you could buy a lot of Honda 2200 on a world tour and still be up.

https://betamarine.co.uk/he-hybrid-propulsion/

That's an interesting find! But it's not an "alternator" in the sense of something mounted on the front of an engine for charging batteries. It's a full-on propulsion system drawing power directly at the flywheel end of the motor and going both ways -- it's either a generator or a propulsion system. And it's certainly not an add-on to an existing engine.


For those that believe in EP, it's a hybrid in a really nice package.

[s/v Jedi]

Originally Posted by Simi 60

Ok on a small battery bank but they only do around 50amps @ 24v - our solar does more at times.

Our charger can put out 120amps @ 24v, so Honda not up for the task.

But that isn’t a valid argument because the next boat will have a 18kW genset and claim your silly small 6kW isn’t up to the task.

[malbert73]

We find the 5.5 KW genset a great setup for us that couldn’t be replaced for our use. First of all we like sailing and the amount of solar on an arch that we would need would be a lot of windage and weight.
Our next gen 5.5 uses about 1/3 gph - and in an hour or two we can bulk up the batteries, make water with our high output AC water maker, and make hot water for showers.
Or when we are on chesapeake bay in the summer we can use the AC unlimited, rarely overnight but we have the option to stay off the dock even when there’s no breeze and it’s 95 and humid. I installed a water/exhaust separator so it’s silent for others if we keep it running.
So for me the use case is that the genset does more than charge batteries. And we don’t have the pressure to use the engine to charge so we sail a lot more. The genset is much quieter and burns much less fuel than our main engine (9 hp Kubota on the genset vs 50hp Kubota on the main)

But full disclosure if AC wasn’t important for our cruising, it would be less clear cut to keep the genset particularly with a Li upgrade. Yes Li can run AC for a short time but replacing the power is the issue

[s/v Jedi]

Originally Posted by malbert73

We find the 5.5 KW genset a great setup for us that couldn’t be replaced for our use. First of all we like sailing and the amount of solar on an arch that we would need would be a lot of windage and weight.
Our next gen 5.5 uses about 1/3 gph - and in an hour or two we can bulk up the batteries, make water with our high output AC water maker, and make hot water for showers.
Or when we are on chesapeake bay in the summer we can use the AC unlimited, rarely overnight but we have the option to stay off the dock even when there’s no breeze and it’s 95 and humid. I installed a water/exhaust separator so it’s silent for others if we keep it running.
So for me the use case is that the genset does more than charge batteries. And we don’t have the pressure to use the engine to charge so we sail a lot more. The genset is much quieter and burns much less fuel than our main engine (9 hp Kubota on the genset vs 50hp Kubota on the main)

But full disclosure if AC wasn’t important for our cruising, it would be less clear cut to keep the genset particularly with a Li upgrade. Yes Li can run AC for a short time but replacing the power is the issue

Check out the solar panel cassette I’m building: you can double the amount of panels while at anchor

[malbert73]

Originally Posted by s/v Jedi

Check out the solar panel cassette I’m building: you can double the amount of panels while at anchor

Is this on a different thread? Definitely want to check it out. But, with only 40 feet LOA don’t think I’m willing to install the kind of solar farm and battery bank to run the AC for 8 hours straight. I’m not disagreeing that it’s possible to get rid of the genset, AC aside.
But, my point is if you do have a genset, using all of the power to do multiple things- like water making, bulk charging, and others- makes sense and is very economical on fuel burn

[Sabado]

Originally Posted by malbert73

Is this on a different thread? Definitely want to check it out. But, with only 40 feet LOA don’t think I’m willing to install the kind of solar farm and battery bank to run the AC for 8 hours straight. I’m not disagreeing that it’s possible to get rid of the genset, AC aside.
But, my point is if you do have a genset, using all of the power to do multiple things- like water making, bulk charging, and others- makes sense and is very economical on fuel burn

I agree. It would be great to never run the generator but we also like the space on the roof for lounging on the “bunny deck” or beanbags.

[s/v Jedi]

Originally Posted by malbert73

Is this on a different thread? Definitely want to check it out. But, with only 40 feet LOA don’t think I’m willing to install the kind of solar farm and battery bank to run the AC for 8 hours straight. I’m not disagreeing that it’s possible to get rid of the genset, AC aside.
But, my point is if you do have a genset, using all of the power to do multiple things- like water making, bulk charging, and others- makes sense and is very economical on fuel burn

Originally Posted by Sabado

I agree. It would be great to never run the generator but we also like the space on the roof for lounging on the “bunny deck” or beanbags.

I guess you guys figure it’ll take your time before they refuse to sell you diesel for pleasure boating but I know I will see that day so I am eliminating the need for any of it. For a 40-footer, you can install 2kW on an arch on the stern, of which half is available at all times and the rest when the array is fully deployed, like while at anchor. (2 + 2 bifacial panels)

For now the thread I am posting on is about making carbon fiber beams to carry it out over top of the hoisted dinghy; I will start a separate thread when I do the first fitting of the cassette assembly.

[Sabado]

Originally Posted by s/v Jedi

I guess you guys figure it’ll take your time before they refuse to sell you diesel for pleasure boating but I know I will see that day so I am eliminating the need for any of it..

We’ll deal with it if that ever happens but I’m not too worried about that happening in the time horizon we’re working on.

I am looking forward to seeing what you’re putting together though. It sounds very cool!

[Sabado]

Originally Posted by s/v Jedi

I guess you guys figure it’ll take your time before they refuse to sell you diesel for pleasure boating but I know I will see that day so I am eliminating the need for any of it. For a 40-footer, you can install 2kW on an arch on the stern, of which half is available at all times and the rest when the array is fully deployed, like while at anchor. (2 + 2 bifacial panels)

For now the thread I am posting on is about making carbon fiber beams to carry it out over top of the hoisted dinghy; I will start a separate thread when I do the first fitting of the cassette assembly.

Just found your FB page. You’ve got some great projects on there!

[s/v Jedi]

Originally Posted by Sabado

Just found your FB page. You’ve got some great projects on there!

Yes I came back here to check if that was you

The Facebook page gets posts as I work on it; I’m currently reinforcing the solar panels and attaching plastic spacers and slides to them for mounting in the cassette

[Sabado]

Originally Posted by s/v Jedi

Yes I came back here to check if that was you

The Facebook page gets posts as I work on it; I’m currently reinforcing the solar panels and attaching plastic spacers and slides to them for mounting in the cassette

Thank you for sharing the progress.

[Kinkircating]

We went without a generator and instead are installing dual Integrel chargers. Also 3.2kW of solar feeding a 29kWh lithium bank at 48V.

[Cheechako]

A gen makes sense if you have AC etc. I removed a good one out of a cat I bought and had 100 amp alternators on each of the engines.
I really wanted the gen weight out of the cat AND this cat already had engine drive refrigeration, so I was going to run an engine anyway.

Having said that, I have mostly opted for a big alternator on all my boats for 40 years and never worried much about running the main engine. I guess maybe if you are the type to keep a boat for decades maybe it would matter, but the reality is a large alternator does load an engine enough to hear it lugging down and it's not like you use the engine only for charging if you are cruising.
Also, if charging, my mode is to put the big amps in and not idle for long. It takes a lot of time to get the last % in a battery and you'll get that next time you move the boat under power anyway.
I always liked the simplicity of main engine charging, no clap trap hanging off the boat, noisy wind devices, trying to charge with other methods. Clean and simple.
I imagine if you dont move around much maybe this is not the best method though.

Starting over today I would have some decent size solar panels but smaller than a Bimini and supplement that with the engine. I never got too much out of two wind power systems.