Sticker shock on marine generators

[Rohan]

I never needed a generator before, but now will likely need one for some upcoming plans.

I thought I had a pretty good idea of pricing based on what I know of portable generators, but OMG I was wrong. The difference is staggering. Compare these two generators, which are roughly the same kw of power - the marine one costs TEN TIMES more than the portable generator. The difference is not always that extreme, but at a minimum, it looks like a marine generator costs at least four times what a comparable portable one costs.

But why?? Even if that price of the marine generator includes a sound shield, installation, and additional corrosion protection, it still doesn't justify a price tag 4-10x higher. Quality doesn't justify the difference either, since I could have replace the cheaper unit several times before it would reach the cost of the expensive one.

Related question. Marine generators use water cooling. It is necessary to create yet another thru hull? Can I instead piggyback off an existing one? I would rather not add another hole to the boat if it can be avoided.

[alex_sauvage]

Marine generators are normally diesel when portable one are gasoline. Diesel engines are generally more expensive and less common, at least in small sizes. So you cannot use economy of scale....But I agree 4-10 times is an overkill. Some people get away with using small generators like Honda 2000..depending how much power you need it might be an option.

[Tillsbury]

Small diesel engines are rare, small petrol engines are common and disposable.

Wait until you find out how much installation costs...

[rslifkin]

A good marine generator is also typically a much higher quality unit than a cheap portable one. More in line with a good fixed-mount land based generator. So beefier, more durable, lower RPM engine, better generator head, better voltage regulation, etc. Plus the marine components for cooling and exhaust.

[Cheechako]

It does seem out of line. Even thinking about the cost of a small diesel... I guess injection pumps and injectors are more expensive than gas injection schemes and spark plugs, but THAT much more? Pistons, valves, blocks have to be similar cost, ignition systems with black boxes are not part of the diesel.... hmmmm
The big thing I suppose is the water cooling system that marine units have.
But you know, I bought a popular brand Chinese home generator, electric start 4500 watts. I think it was $350 delivered by truck. It's lasted years and never misses a lick.

I do use non alcohol gas in it. They should make a water cooled version for marine. The only reason you cant use a Honda 2000 in a locker is the air cooling.

[alex_sauvage]

Google search shows that small diesel generator 6-8kW will run you about 4k. Interestingly some are aircooled that can drastically decrease installation cost. I am wondering if anyone tried to install those on a boat?..Noise might be an issue however...

[Cheechako]

Originally Posted by Rohan

I never needed a generator before, but now will likely need one for some upcoming plans.

Related question. Marine generators use water cooling. It is necessary to create yet another thru hull? Can I instead piggyback off an existing one? I would rather not add another hole to the boat if it can be avoided.

You can, depends on what that seacock delivers to. Some situations it will suck bubbles in the cooling water and you'll hear a gurgling noise. (dont ask how I know!)
If a cockpit drain is well under waterline, I would think teeing off something like that would be fine.
I once tee'd off the main engine inlet, it worked fine because I never used the main engine and generator at the same time.

[Cheechako]

Originally Posted by alex_sauvage

Google search shows that small diesel generator 6-8kW will run you about 4k. Interestingly some are aircooled that can drastically decrease installation cost. I am wondering if anyone tried to install those on a boat?..Noise might be an issue however...

Well, even if the engine is air cooled, you'll still need water cooling for the exhaust for safety. Unless you have an arrangement for a insulated dry stack somehow.

I have wondered before if a wet exhaust just using an electric water pump could be employed on an air cooled generator. Seems feasible with a heat sensor T stat for if the pump fails. You'd need forced air cooling in a locker maybe though...
I built a few small diesel gen's that were 12V. Thought about trying it with an electric pump, but a belt water pump is so easy to do...
Watermaker Gen combo, but I built smaller ones too...

[Bill Seal]

He's comparing air cooled gasoline powered generators, marine vs RV.
If you're looking at water cooled marine diesels, they'll cost about the same as a small sailboat diesel, only difference being transmission or generator head.

[Cheechako]

There are also Yanmar and Kubota small air cooled diesels.

[Dsanduril]

In fact, the Generac Portable Diesel Generator uses a Yanmar engine. And starts at about half the price of the OP's linked marine one and 5x Generac's price for the same size generator in gasoline.

[DanCan]

Originally Posted by Dsanduril

In fact, the Generac Portable Diesel Generator uses a Yanmar engine. And starts at about half the price of the OP's linked marine one and 5x Generac's price for the same size generator in gasoline.

Ok, I’ll chime in. This is exactly what my sister and brother in-law bought for their house in an area prone to power outages (in the USA). They are amazing, but you don’t want this in a boat, I’m telling you!

[Dsanduril]

Yeah, I certainly don't think I'd want one, be pretty hard to get a sound enclosure that would keep that noise down. More to point out the difference between gasoline and diesel power from the same supplier.

[DanCan]

Originally Posted by Dsanduril

Yeah, I certainly don't think I'd want one, be pretty hard to get a sound enclosure that would keep that noise down. More to point out the difference between gasoline and diesel power from the same supplier.

Noisy (although not unbearable like the old one, but yeah, noisy), expels lots of heat, it is bulky (around the size of a dishwasher) and it is gasoline! For the house, they can run the fridge/freezer and turn the Ac at times to keep the house cool enough. It muscles a lot of power!

[S/V Illusion]

An ‘apples to apples’ comparison. Our home standby generator costs about the same as does our marine generator. Conversely, my little portable Honda 2000 costs very little by comparison. Frame of reference issue.