Poor man's genset (is this a crazy thing to do?)

[patrickstickler]

I've been wanting a genset for awhile. Solar doesn't do much for me this far north (Finland) and I tend to prefer to anchor where there isn't alot of wind, so wind generators aren't optimal.

But dedicated marine gensets are rather pricey.

There are more and more inexpensive air-cooled portable diesel generators on the market. E.g. the following can be had for around 600 euros:



What I'm thinking is to get one of these and install it in one of the lazarettes, with the intension of running it with the lazarette hatches open, and with the exhaust vented out in similar fashion to a Wallas heater (probably using Wallas parts), with fuel taken directly from the main tank, and with the shore power cord plugged in to its AC output. It's electric start, so should be fairly user-friendly.

It would be a tad bit noisier than a dedicated marine genset, but tolerable (about 70db).

(And before anyone suggests it, no I won't have either gasoline or propane on my boat, so the typical small Honda generator is out)

My only concern is heat. Not sure just how much air cooling is needed for one of these, and whether it would be enough to just have the hatches open or whether a bilge blower would be needed.

Comments?

[norsearayder]

iam up north 43 degrees[maine usa] i have two 85 watt solar panels and they really provide a lot of elctritcy [only 12 hrs of light now] if you sail mostly in the summer solar will work for you.

[patrickstickler]

Originally Posted by norsearayder

iam up north 43 degrees[maine usa] i have two 85 watt solar panels and they really provide a lot of elctritcy [only 12 hrs of light now] if you sail mostly in the summer solar will work for you.

I'm above 60 degrees, so a bit more sun-challenged.

Between heating (Wallas 40D), fridge, and general lighting and electronics, my power draw is around 3-4A which is more than I am expecting from solar except in the middle of the summer (unless I cover the whole deck in panels).

From a 400AH house bank, I want to be able to manage around 3 days before having to run the genset (currently have 200AH in the bank, need to add more).

Early and late in the season, it's usually overcast, and the days are short, so I'm not trusting solar to do the job except during the middle of summer.

The attraction of the genset is that it will just plain work. True, it's not "green", and is noisy, but it will do the job no matter the weather or time of year.

[JimsCAL]

A diesel is less than 50% efficient, so for example a 5kW generator is going to put out more heat than a 5kW heater. I suspect you are going to need some sort of a blower.

[tommays]

There is no air cooled unit i know of that meets CE or USCG or any saftey standard

[75R20]

Sorry for my english, but I haven't spoken/written finnish since my grandfather died many years ago.
I say "go for it" You are aware of the cooling concerns, and the noise output. At worst,. you will need to "Powervent" the cabinet. If it doesn't work the generator has other purposes, and could come in handy.
Good to hear from the "old country" I want to sail there sometime.
Best of luck
Kary
S/V Mariah
#49080

[JohnRPollard]

Patrick,

That is an interesting option. I am not a fan of the gasoline generators either, so I find this diesel intriguing.

But when I look at these separate generator options, I find them very difficult to justify. I can see where they make sense for folks that are running air-conditioning or other high loads on a continuous basis, but beyond that? They sure take up a lot of valuable storage space.

You already have a diesel generator on board -- the auxiliary. Since you plan to have a house bank that can go upwards of 3 days before recharging, why not just charge it from the auxiliary engine? You could invest your money in a high output alternator, and reduce charging times. You might even consider adding a PTO and a second alternator.

Very few of us will wear out our auxiliary engines from hours. Most are designed to go 3-4k hours before rebuild. The key is to have them loaded while running, as much as possible. A second high-output alternator (switched for use on-demand), can help with that. Higher-output alternators also help to maximize charging while motoring underway, which reduces or extends the interval for charging times at anchor.

Anyway, that's just my take on the generator idea. I would personally avoid adding the complexity of maintaining a second engine and losing the storage space, unless I absolutely needed it.

[Westlake2]

Patrick:

Please take great care with this choice. At best, this little diesel genset could be used on a back deck or on top of a house, but NOT inside your boat anywhere. It is an air cooled device and should not be limited in terms of air flow in any way. A small portable like this can be stored inside or below, but never run there.

Contrary to some popular belief, diesel engines produce carbon monoxide in a significant quantity. They also shake pretty hard and will damage most attempts at flexible exhaust systems connected in any kind of casual fashion. Most certainly, Wallas flexible stainless hose/pipe is not up to the task, nor is it intended for it. My guess is the generator engine does not have a hard flange for attaching a pipe anyway.

The exhaust from a naturally aspirated diesel engine will probably exceed 900 degrees F (480 C), the exhaust system should not be something that is built in any kind of ad hoc fashion. This is a very serious consideration.

My background includes 20 years in marine power generation and I will contend that there are very good reasons for the way marine diesel generators are built. I now distribute Wallas in North America, which is part of my reason for clarifying our position on your proposed application of our exhaust component(s).

Thank you.

[patrickstickler]

Thanks. I've basically nixed the idea, and will look around for a used marine genset.

Cheers.