Installing a Generator

[Irish Rover]

I had been hoping to change my boat this year for something bigger with a generator, deep freeze and water-maker. Unfortunately that's not happening now (covid, business, shit happens) and so I'm looking at the possibility of fitting a generator and a deep freeze (will be another thread if we sort the genny). My boat is a power cat and space is not really a problem. There's plenty of space in both engine compartments so I'd prefer a fixed installation rather than the suitcase type. So I want something smallish and as quiet as possible. It's main job would be to power a deep freeze and the existing fridge and maybe an electric hotplate instead of the gas bbq. So please tell me what meets my requirements. Will I need a thru hull for sea water cooling or will the space in the engine bay be enough for air cooling - it was 41C here yesterday but cooler today TG.

 

[jwfrary]

Well first of all you need to add up all your power requirements,

If space and weight aren't too critical then I would go for an acoustically housed 1500 rpm unit. A beta gen 7 is a good unit which is simple and competitively priced.

1500 rpm generators are longer lasting too!

 

[harvey38]

Definitely need a through hull if you go for a permanently installed genset but if you are only using it for a deep freeze/fridge and depending on size of hot plate and usage, I'd consider upgrading the battery bank and a decent capacity inverter.

Just a thought.

 

[jwfrary]

Oh and dont be fooled by the number the manufactur puts on the label.

For instance a beta gen 7 has a prime output of 5.7 kva

Output is usually around 80% of the labels output is a good rule of thumb!

 

[jwfrary]

Theres also integrel which might be worth a look

https://integrelsolutions.com/

Depends on the type of cruising you do

 

[Simi]

if it’s only for a deep freeze there are plenty of very good compressor fridge freezer large cool box type fridges they work on 12 or 240v
we had a 140litre Polarbox last year 2 compartments it was excellent but was to big for our boat so sold it and got a smaller one

 

[Simi]

if you are fitting a gen Onan or Fisher Panda are very good

 

[Bouba]

For a start, with a power cat and 41degrees of sunshine, you may have room for an entire array of solar panels. The other possibility is a propane freezer, I had a gas fridge on my motorhome, and it worked great. It would automatically switch between shore power (campsite), 12v (as soon as you started the engine) and bottled gas (as soon as you parked). All seamlessly. Bottled gas is a great energy store, easy to refill in any town in the world and long lasting.
Because, if you get a genny, you might as well get one that doesn’t pop the tripswitch everytime you put the kettle on, it gets boring plugging and unplugging. But you are looking at €17k

 

[jwfrary]

if you are fitting a gen Onan or Fisher Panda are very good

I would contest the Fisher pandas are good, I find them prone to electrical gremlins and the pumps on the smaller units rather under spec. Also the price is pretty crazy!

Onans are great units. But again quite pricey. A beta is based on the same engines as the onan and to be honest the acoustic housing is better on the beta.

 

[jwfrary]

I priced a 12 kva 1500 rpm set by perkins for a commercial vessel the other day it was 8 k plus vat.

If you have a nice flat place to install it already it won't cost a bomb, water in, battery and exhaust is all it needs other than hooking up to your electrics.

I expect a beta would be a similar price unfortunately the beta won't fit in the gap I have (the 12 kvas to long and the 14 is too tall hence the perkins which is a short 3 cylinder)

Visa energy was the dealer for that. Haven't bought it yet so I can't endorse that one!

 

[William_H]

You can't escape the fact that more cylinders ie 3 cyl has least vibration and noise. ol'will

 

[Pete7]

Seems you are adding a third engine and a lot of weight. Have you thought of adding a big alternator to one or both engines? There are some interesting YT videos by Sterling Power on the subject of charging, aimed at the caravaners, but equally suitable for yachties. Its based on modern cars having quite big alternators and how to use this potential to the best advantage. However, even a smaller yacht engine could have an alternator upgrade or second one fitted.

That and lots of solar would be good and save the £7000 price tag for eve the smallest Fischer Panda genny.

Pete

 

[vas]

I'd do my calcs carefully, and fit 800W panels on the "roof" of the powercat. A decent MPPT Victron charger and/or a combo charger/mppt/inverter is what you need. Of course that lot should be matched with decent sized battery bank.
After all where you are sunshine is free and lots of it.
just to compare, my 43ft mobo has two 300W panels on the f/b hardtop (panel size is 1X2m each) a victron inverter and I can run two 80lt fridges, all my electronics, laptops, etc for free everyday.
I do have a 8kva generator for watermaker/aircon (that I v.rarely use) and other big tools.

In your case, it's a matter of what skillfull and reliable ppl you have in your area more than anything else.

V.

 

[jwfrary]

I'd do my calcs carefully, and fit 800W panels on the "roof" of the powercat. A decent MPPT Victron charger and/or a combo charger/mppt/inverter is what you need. Of course that lot should be matched with decent sized battery bank.
After all where you are sunshine is free and lots of it.
just to compare, my 43ft mobo has two 300W panels on the f/b hardtop (panel size is 1X2m each) a victron inverter and I can run two 80lt fridges, all my electronics, laptops, etc for free everyday.
I do have a 8kva generator for watermaker/aircon (that I v.rarely use) and other big tools.

In your case, it's a matter of what skillfull and reliable ppl you have in your area more than anything else.

V.

I agree this is a workable solution for lots of people, it's all down to how you use your boat.

Decent batteries/inverter and panels could add up to nearly the same as a generator.

Its going to be down to your cruising patterns and behaviours.

The great joy of the inverter charger systems is that they are silent overnight! Of course you have to put some charge into them afterwards some how, if you can do it with enough solar your cooking! But not on gas....

 

[Irish Rover]

I'd do my calcs carefully, and fit 800W panels on the "roof" of the powercat. A decent MPPT Victron charger and/or a combo charger/mppt/inverter is what you need. Of course that lot should be matched with decent sized battery bank.
After all where you are sunshine is free and lots of it.
just to compare, my 43ft mobo has two 300W panels on the f/b hardtop (panel size is 1X2m each) a victron inverter and I can run two 80lt fridges, all my electronics, laptops, etc for free everyday.
I do have a 8kva generator for watermaker/aircon (that I v.rarely use) and other big tools.

In your case, it's a matter of what skillfull and reliable ppl you have in your area more than anything else.

V.

Thanks all for the replies and suggestions.
@vas I'm going to look seriously at meeting my requirements with solar panels. At the moment I have 2 solar panels mounted on a frame aft of the flybridge. These are old Shell panels dating from around 2006 and are rated 85W each. I didn't measure them but I think they're around 120 x 60. They are connected to the batteries via 2 x Stecca controllers. I have 2 battery banks with 3 house batteries in each all operating in parallel with a total output of 540AH. I also have 2 separate starter batteries. I note you think i'd need 800W of solar. What total AH house battery capacity do you think I'd need? Thanks, as always, for your expert advice.

 

[jwfrary]

Well enough you can service all your loads for 48hrs with no sun would be about right.

Add your loads up first!

Dont forget to de rate your inverter for the higher ambient temps in the med