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Genny vs engine vs solar?


Jak

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I’ve been wondering about this. With little experience we have probably missed a trick or two.   I have 300w solar which is great in the summer and is still bringing in some power now in deepest winter. I fitted  an uprated alternator with my new batteries (Only 55amp as it’s an easy replacement on the 1500bmc diesel) to replace the original. Running the engine for a couple of hours a day when needed uses little diesel and provides our hot water. Boat is off grid. I fitted 3 new cheapo leisure batteries 5 years ago and they are still performing well so not managed to knacker them yet.  Why would someone need a genny?  The noise, security and petrol issues seem to rule them out. 
 

thanks. Jak. 

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10 hours ago, Jak said:

I’ve been wondering about this. With little experience we have probably missed a trick or two.   I have 300w solar which is great in the summer and is still bringing in some power now in deepest winter. I fitted  an uprated alternator with my new batteries (Only 55amp as it’s an easy replacement on the 1500bmc diesel) to replace the original. Running the engine for a couple of hours a day when needed uses little diesel and provides our hot water. Boat is off grid. I fitted 3 new cheapo leisure batteries 5 years ago and they are still performing well so not managed to knacker them yet.  Why would someone need a genny?  The noise, security and petrol issues seem to rule them out. 
 

thanks. Jak. 

Beyond me too. Must be the most expensive way of generating electricity.

But then some people cannot accept that they are not living in a power station that will run all the gismos that the land lubbers seem to want.

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Further, if you look at other boats you'll notice a good proportion still don't have ANY solar at all. Some boaters simply don't grasp the value of it and persist in running noisy generators for hours every day. Like the boat moored opposite me a few months back. 

 

I also think some boaters use a genny because inside the boat, it is quieter than with a big 'ol air cooled Lister revving away. And they are too tight-fisted or poor to get a solar installation done. Some redundancy is always a Good Thing too when it comes to having ways to get the leccy. 

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I have a BMC engine and a genny. 

 

Reason 1: Believe me, a halfway decent genny is far, far quieter than the boat engine, and creates no annoying vibration.  The experience inside the boat is so much better.  The sounds actually carries less outside too, as the genny runs on the bank, whereas the boat engine sends sound through the water which can annoy other boaters a surprising distance away. 

 

Reason 2:  It's cheaper to run than a boat diesel.  My genny uses a fraction of the fuel per hour that my boat engine does.

 

Reason 3:  Less wear and tear on the boat engine.  The engine is the single most valuable thing on the boat, costing thousands to replace when it wears out.  A good genny can be had for a few hundred quid when you need a new one.

 

Reason 4:  Redundancy.  What do you do for power when it's winter and your engine won't start?  At some point, this will definitely happen, so be prepared.

 

Reason 5:  Rather than adding strain to your batteries by making them drive an inverter while you run high powered appliances (eg washing machine), a genny will put no load on your batteries at all, and will actually be charging while you are doing your washing.

 

I spent around £500 for a decent new genny.  But a basic second hand one can be had for less than £100 and kept as a back up.  Basically, running an engine to power an alternator to charge batteries to create 12v power to run an inverter to make it 240v is a horribly complicated and inefficient way to get electricity.  Your engine was not designed to do this, but a genny was.

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15 minutes ago, MtB said:

Further, if you look at other boats you'll notice a good proportion still don't have ANY solar at all. Some boaters simply don't grasp the value of it and persist in running noisy generators for hours every day. Like the boat moored opposite me a few months back. 

 

I also think some boaters use a genny because inside the boat, it is quieter than with a big 'ol air cooled Lister revving away. And they are too tight-fisted or poor to get a solar installation done. Some redundancy is always a Good Thing too when it comes to having ways to get the leccy. 

I don't have solar panels and am neither tight fisted nor poor. Why do I not have panels ? Because I need safe access to the roof when single handing through locks. I DO have a generator! It's a cocooned water cooled 4 Kva in a soundproofed cockpit locker and makes about as much noise (or less) than my BMC 1.8  on tickover

Edited by Slim
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18 minutes ago, Slim said:

I don't have solar panels and am neither tight fisted nor poor. Why do I not have panels ? Because I need safe access to the roof when single handing through locks. I DO have a generator! It's a cocooned water cooled 4 Kva in a soundproofed cockpit locker and makes about as much noise (or less) than my BMC 1.8  on tickover

 

Fair comment.

 

There may be thousands of boaters out there like you with silent cocooned gennys who run them willy nilly at all times of day and night, and neighbouring boaters and householders would never know! 

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Thanks for your advice.  Solar was the best upgrade ever but, like everyone says, it’s not great at this time of year. We survived the last few winters so let’s see. 
 

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23 minutes ago, sueb said:

We survived for 25 years with no solar or generator. The engine didn't need running daily either.


Where did you get your leccy from?  Our boat was 12v only to start with, but I still wanted to watch my 12v telly and charge my phone….

 

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1 hour ago, LadyG said:

In summer

Wrong! I have for many weeks been on solar only, yes I have a lot of solar but I also have a dishwasher and washing machine on board. I have a 6Kw genny as well but have not needed it as its been sunny this January and February isn't looking bad either. 

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35 minutes ago, magnetman said:

To be fair you do have a LOT of solar rather than just a lot of solar and as I understand it also rather nice batteries ;)

 

 

Widebeam boat and wheelhouse would be a shame to waste that roof space Andrew 😊

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57 minutes ago, Jak said:


Where did you get your leccy from?  Our boat was 12v only to start with, but I still wanted to watch my 12v telly and charge my phone….

 

Many people on boats didnt have tvs, Sue lived aboard when most people didnt have mobile fones and certainly not smart fones/computers. We have all over the years got used to far more lectrical stuff than we realy need. 12 volt only is no problem for basic living. I myself had moocho lectric available on my last few boats but it isnt realy necessary.

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I have a generator for two reasons - redundancy and the washing machine. Zanussis simply don’t play nice with Victron inverters, so once a week I fire up the genny for the wash. 
 

It’s also handy for power tools, as a 1600w chop saw inrush current will trip my 2kva inverter. Oh and one final use…with a 240v pump, it’s very useful to save a boat from sinking. Used it a couple of times to help neighbours like this. 

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23 hours ago, Jak said:


Where did you get your leccy from?  Our boat was 12v only to start with, but I still wanted to watch my 12v telly and charge my phone….

 

Leisure batteries. No TV although I used laptop every evening on 12v. Gas fridge. Phone charged on 12v.

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22 hours ago, mrsmelly said:

Many people on boats didnt have tvs, Sue lived aboard when most people didnt have mobile fones and certainly not smart fones/computers. We have all over the years got used to far more lectrical stuff than we realy need. 12 volt only is no problem for basic living. I myself had moocho lectric available on my last few boats but it isnt realy necessary.

I did have a smart phone (I phone) and laptop both worked well on 12v. We used an inverter very infrequently if we needed 240v. 

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On 03/02/2022 at 09:56, doratheexplorer said:

I have a BMC engine and a genny. 

 

Reason 1: Believe me, a halfway decent genny is far, far quieter than the boat engine, and creates no annoying vibration.  The experience inside the boat is so much better.  The sounds actually carries less outside too, as the genny runs on the bank, whereas the boat engine sends sound through the water which can annoy other boaters a surprising distance away. 

 

Reason 2:  It's cheaper to run than a boat diesel.  My genny uses a fraction of the fuel per hour that my boat engine does.

 

Reason 3:  Less wear and tear on the boat engine.  The engine is the single most valuable thing on the boat, costing thousands to replace when it wears out.  A good genny can be had for a few hundred quid when you need a new one.

 

Reason 4:  Redundancy.  What do you do for power when it's winter and your engine won't start?  At some point, this will definitely happen, so be prepared.

 

Reason 5:  Rather than adding strain to your batteries by making them drive an inverter while you run high powered appliances (eg washing machine), a genny will put no load on your batteries at all, and will actually be charging while you are doing your washing.

 

I spent around £500 for a decent new genny.  But a basic second hand one can be had for less than £100 and kept as a back up.  Basically, running an engine to power an alternator to charge batteries to create 12v power to run an inverter to make it 240v is a horribly complicated and inefficient way to get electricity.  Your engine was not designed to do this, but a genny was.

 

You make some very good points here, and whilst I agree with most, it might be worth adding in a slightly different perspective to some of them. 

My initial mistake was to buy a £200 suitcase genny from Amazon, which was advertised as silent.

I knew that for £200 it wasn't really going to be silent, but I was dismayed at how 'not silent' it was. I think it was about 90db at 5 metres away, which is a lot.

I did consider making a box to house it, and lining it with some noise-reducing panels, but in the end I gave it away to someone who could put it to good use. 

I'm concerned that I have no contingency plan for the engine failing in winter, but on the other hand I dont really want to have a genny sat in the cratch for the next few years unused, until the dreaded day of engine failure comes. 

My boat is now about 6 years old, so fingers crossed I'm not expecting any major failures in the next couple of years (and I have RCR to fix minor things)- so at the moment I'm rather uneasily gambling that I wont need a genny. 

The solar panels mean that my period of being 'at risk' is reduced a lot. 

I have almost 1400 watts of solar, which generates the electricity I need for about 75% of the year. Even today, in early Feb, because there was a bit of sun this afternoon I got 1800 watt hours of charge into the batteries, and I havent had to run the engine for the last 2 days. 

The other mitigation I have is that I can charge the batteries at 90amps or more, so even in winter I can get a days charge in about an hour. Some days, if there is a bit of sun, its half an hour. 

I have a sort of fall-back plan that if I do have a major engine failure, I can order a new genny from a local supplier, and hire a small van to get it to the boat. 

But being honest, I'm not convinced that plan would go as smoothly as I've made it sound, and it is a bit of a nagging doubt.

 

 

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I wish I was allowed a gas fridge. We had one on our caravan and it worked well. The previous owner “upgraded” the boat fridge to 12v. I don’t see that as any sort of upgrade as without a leccy fridge we would need very little power.  Again did I miss something?  Gas fridge on the face of it is a better solution?  Why not??

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6 minutes ago, Jak said:

I wish I was allowed a gas fridge. We had one on our caravan and it worked well. The previous owner “upgraded” the boat fridge to 12v. I don’t see that as any sort of upgrade as without a leccy fridge we would need very little power.  Again did I miss something?  Gas fridge on the face of it is a better solution?  Why not??

Again, you are correct. Gas fridges are brilliant for boats. Our first boat had an old gas fridge. Of course as we got newer " Better " boats over our 30 plus years of living aboard the old gas fridges dissapeared.  Our last 3 boats had all mod cons and mains everything which is great. However, there is a lot to be said for a gas fridge and instant gas water heater. Much less leccy needed.

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28 minutes ago, Jak said:

I wish I was allowed a gas fridge. We had one on our caravan and it worked well. The previous owner “upgraded” the boat fridge to 12v. I don’t see that as any sort of upgrade as without a leccy fridge we would need very little power.  Again did I miss something?  Gas fridge on the face of it is a better solution?  Why not??

 

What have you been told that makes you think you not allowed a 'gas fridge' ?

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On 03/02/2022 at 10:02, Slim said:

I don't have solar panels and am neither tight fisted nor poor. Why do I not have panels ? Because I need safe access to the roof when single handing through locks. 

I had the same concern before having my panels fitted, but ended up with some slimline ones (150w each) which left a comfortable walkway on either side. 

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