Genny's

[Cafnod]

Hi B/R

LPG is roughly 2/3 - 3/4 of petrol running costs, halfway between petrol and diesel. Engines definitely run hotter, and as you may know if an engine runs hotter, ie in adverse conditions, then oil changes have to be more frequent. I would imagine if Honda UK are reluctant to comment then they have not done the relevant research and development, which suggests to me that they are not interested in that area of the market.

As R & D is a MINIMUM of 2 years ahead of market availability it suggests they may have something else in the pipeline.

I am not going to comment on the cost of our genset, but I will say that it was very very cheap, it came out of a dutch barge on the Thames that was having a superstructure refurbishment and they needed it gone NOW. It was not outputting due to a wire having vibrated loose in the outlet socket, so it had to be sold as not working.

So I sang them a song, took it home and fixed it and then fitted it myself, cost in steel and welding rods about £25.

Edited April 22, 2007 by Cafnod

[anhar]

On the Hondas, it costs a bit for the LPG conversion. For example on the EU20i, it adds £170 to the cost of a new one whose basic price is £889 from Just Generators. Don't know about Mike's EU30is or what Edge Technology charge, they don't show prices on their site. Thus taking Cafnod's figure of the lower running costs of LPG against petrol, it would probably take some time to cover the conversion cost with the money saved in running.

 

In figures, the EU20i consumes 4.1 litres in 10.5 hours at 1/4 load according to the spec. from JG. Taking petrol at say £1 per litre that then costs 410/10.5 = 39p per hour. If LPG would cost say 25-33% less according to Cafnod, this saves about 10-13p per hour. Call it 11.5p average. At an additional £170 for the conversion on this model, it would therefore take 1,478 hours to break even. That is quite a long time depending how many hours a day and days a year it is run.

 

In Mike's case for two months a year, at say 4 hours per day, that is about 240 hours per year and it would take six years to break even on fuel. However that is the EU20i, the EU30is consumes more, 13 litres per 25 hours equal to 52p per hour of petrol. I don't know what the gas conversion costs for the latter model so can't do any calculations for potential time to break even.

 

Whatever though, it appears that money saving should not really be the reason to go gas because break even takes too long unless it is used very heavily and throughout the year, which could be the case for liveaboards without shore lines. Other benefits ought perhaps to be the primary reason such as gas being more readily available on the canals than petrol for example.

 

regards

Steve

[Cafnod]

Gas is more readily available as you say steve, it also gives a cleaner emission. Added to that all of us with enough room to carry a reasonably sized generator have a safe storage locker for at least two 13kg gas bottles.

However there is the long term economic factor and the warranty issues of using gas.

I have thought about it when I ran big petrol gensets but I am in the happy position where that is no longer an issue.

[blackrose]

Yes, it's the other benefits like not having to bring petrol on board which would be my motivation for buying a conversion kit. Since I have a locker big enough for 3 gas bottles I can have a dedicated bottle for the generator. I think the conversion kits are about £135 + vat from Edge.

 

Thanks for doing those sums for us Steve I will bear in mind that the cost savings are not a good reason for me to convert to LPG

 

I didn't realise the EU30i had a higher fuel consumption figure than the EU20i. Are you sure about this? As you say, the EU20i has a 4.1 litre fuel tank and runs for 10.5 hours (0.39 l/h), and the EU30i has a 13 litre tank and runs for 25 hours (0.52 l/h), but these figures are at 1/4 load which for the EU20i is 400w and for the EU30i is 700w (I'm using the rated watts figures). I think if we run both generators on the same load the EU30i might have a lower fuel consumption?

[Cafnod]

The 3kw genset will have the higher fuel consumption, load for load because the bigger engine is less fuel efficient and the bigger alternator will be heavier increasing fuel consumption too.

In all honesty I would be surprised if anyone ran a genset at 1/4 load for any length of time, most of the time I use gensets at half to three quarters rated load, otherwise it is just not worthwhile running that size set. If I were going to only draw 400 - 700w I would run an 850w suitcase genset, no point putting the wear and tear on a big set to run it that light.

So I would look at the sums at higher loads to see what consumption figures that gives.

[NB Alnwick]

The 3kw genset will have the higher fuel consumption, load for load because the bigger engine is less fuel efficient and the bigger alternator will be heavier increasing fuel consumption too.

In all honesty I would be surprised if anyone ran a genset at 1/4 load for any length of time, most of the time I use gensets at half to three quarters rated load, otherwise it is just not worthwhile running that size set. If I were going to only draw 400 - 700w I would run an 850w suitcase genset, no point putting the wear and tear on a big set to run it that light.

So I would look at the sums at higher loads to see what consumption figures that gives.

 

This is an interesting point - particularly since we received advice that appears to be to the contrary.

Our existing Chinese built, 230 volt, 3000 rpm generator is rated at 900 Watts continuous. When charging batteries via the Sterling 15 Amp 24 volt charger which draws (according to my meter) between 275 and 350 Watts for eight hours a day this is reckoned by the distributers as probably too high and they have advised that I should use a higher rated genset?

 

Am I missing something?

[John Orentas]

In all honesty I would be surprised if anyone ran a genset at 1/4 load for any length of time, most of the time I use gensets at half to three quarters rated load, otherwise it is just not worthwhile running that size set. If I were going to only draw 400 - 700w I would run an 850w suitcase genset, no point putting the wear and tear on a big set to run it that light.

 

 

I would say 1/4 load would be quite acceptable. Compare that with the normal output of your drive engine, it is normally accepted that to push a narrowboat along at 4 mph needs only 5 bhp. So most of the time assuming your engine is rated at 40 bhp for most of it's life it is only delivering one eighth of it's rated output.

Edited April 22, 2007 by John Orentas

[Cafnod]

Comparing the type of propulsion engine fitted to the type of generator in use is not a fair comparison. That same propulsion engine on rivers, against current will work much harder,and it is designed to be able to cope with these condtitions continuously. The fact that canal boats are often run for long periods under very low power output conditions does not make this either the accepted norm or even a particularly good thing for the engine. Most canal boats are fitted with modern Japanese plant engines, marinised by third parties, these engines are designed to work with a comfortable reserve, half to one third being the norm.

If a set is rated at 900 watts continuous and it is being used at a third of this why should you need to use a bigger set?

What size set are they suggesting you should use? I would have thought the one you were using was just about perfect.

What I would wonder about was whether or not the cheaper two stroke sets were up to the rigours of day to day use.

I cannot comment on that, all my petrol gensets for both AC and DC use have been Hondas, one of mine, 1600 watt is late 60's and still goes well, I ran it for most of my smaller power tool use in fitting out our boat.

Anything over 4kw I have ran on diesel, usually much bigger sets, most were attached to a Gardner 6LX or a big Cummmins or similar, however the same equations applied, we certainly never kept a 75% reserve on our sets for continuous use and I have not on smaller domestic sets.

[blackrose]

I didn't think petrol engines suffered from low loads like diesels? So what's the problem with 1/4 load on a Honda EU?

[anhar]

...I didn't realise the EU30i had a higher fuel consumption figure than the EU20i. Are you sure about this? As you say, the EU20i has a 4.1 litre fuel tank and runs for 10.5 hours (0.39 l/h), and the EU30i has a 13 litre tank and runs for 25 hours (0.52 l/h), but these figures are at 1/4 load which for the EU20i is 400w and for the EU30i is 700w (I'm using the rated watts figures). I think if we run both generators on the same load the EU30i might have a lower fuel consumption?

Hello Mike

 

My purpose with those calculations wasn't to compare the relative consumptions of the EU20i and EU30is but to see how long it would take to break even on a gas conversion with the lower fuel costs of gas against petrol that Cafnod indicated. I did it for the 20 simply because I didn't have the gas conversion cost for the 30 you have. Whether the 30 uses more or less fuel than the 20 for a given output I wouldn't know but according to Cafnod the bigger generator would use more. But as I say that wasn't my point.

 

As you have now given the Edge gas conversion cost at £135 + VAT = £159 the break even can be calculated for the 30 you have.

 

At 0.52 l/h the cost of running the 30 on petrol at say £1 a litre at 1/4 load is £0.52. The gas cost on Cafnod's estimate is 25-33% less, ie. 13-17p less, call it an average of 15p cheaper. Thus at a cost of £159 it would take 159/0.15 = 1,060 hours to break even on fuel alone. Using your two months a year at say four hours per day as per my previous estimate, it will be 4-5 years to break even, much less for a heavy user. Though as I suggested earlier and with which you and others seem to agree, cost isn't really the decisive factor in going for gas.

 

Incidentally how are you going to store a heavy beast like the EU30is on your boat, compared with the smaller model you have now?

 

regards

Steve

Edited April 23, 2007 by anhar

[NB Alnwick]

If a set is rated at 900 watts continuous and it is being used at a third of this why should you need to use a bigger set?

What size set are they suggesting you should use? I would have thought the one you were using was just about perfect.

What I would wonder about was whether or not the cheaper two stroke sets were up to the rigours of day to day use.

 

Our genny has a four stroke engine (Chinese 'Honda copy') and the engine appears to be coping with the load - I suspect the problem is with the alternator. After several hours of continuous battery charging the voltage starts to drop - 215v down to 125v then 62v then 31v which is quite useless. If I switch it off, wait a while and start it up again with no load I get 230v at 55 Hz. The latter is slightly worrying but the plate says that it delivers 230v at 50/60 Hz.

 

A call to the importer (SIP of Loughborough) yielded the suggestion that it wasn't really designed for the this type of application - i.e. continuous load charging batteries - and they would expect that after two years of this kind of treatment it is almost ready to 'cough and die'!!! Their suggestion was that I upgrade to an 1800 watt industrial version.

 

Even so - as the unit cost us less than £100 we have probably enjoyed the service we paid for - the engine is still fine after about 700 hours of use and it still starts first pull with the original oil and spark plug - both still clean and serviceable. In fact, the only servicing that has been necessary is checking these items and topping up the oil. And it has given excellent faultless service until the last couple of weeks.

 

It may be that there is a minor problem with the alternator that can be fixed - but the attitude of the importer was that these are cheap consumable units - when one breaks you bin it and get another. That is what they would do if it was still under the 12 month guarantee . . .

[Theo]

That's what I want to avoid, annoying anyone (and me). I really do like the quiet life, so having something that won't be a bother for a couple of hours is what we need.

 

Just wondering how other towpath dwellers achieve battery charging for the day? We have the solar panel which is going to be great in summer and means not having to run the engine for too long or too often.

 

Would rather try and do what other do, so we don't clash and certainly don't want to cause any bad feelings.

 

The solar panel will cerainly help and can be made much more effective if you angle it to be at right angles to the dirtection of the sun. that could meen continually adjusting it though the day but tilting it up to 55 degrees or so and pointing it south will make a big difference.

 

Nick

[anhar]

Our genny has a four stroke engine (Chinese 'Honda copy') and the engine appears to be coping with the load - I suspect the problem is with the alternator. After several hours of continuous battery charging the voltage starts to drop - 215v down to 125v then 62v then 31v which is quite useless. If I switch it off, wait a while and start it up again with no load I get 230v at 55 Hz. The latter is slightly worrying but the plate says that it delivers 230v at 50/60 Hz.

 

A call to the importer (SIP of Loughborough) yielded the suggestion that it wasn't really designed for the this type of application - i.e. continuous load charging batteries - and they would expect that after two years of this kind of treatment it is almost ready to 'cough and die'!!! Their suggestion was that I upgrade to an 1800 watt industrial version.

 

Even so - as the unit cost us less than £100 we have probably enjoyed the service we paid for - the engine is still fine after about 700 hours of use and it still starts first pull with the original oil and spark plug - both still clean and serviceable. In fact, the only servicing that has been necessary is checking these items and topping up the oil. And it has given excellent faultless service until the last couple of weeks.

 

It may be that there is a minor problem with the alternator that can be fixed - but the attitude of the importer was that these are cheap consumable units - when one breaks you bin it and get another. That is what they would do if it was still under the 12 month guarantee . . .

There's one answer Graham. Honda. But you probably know that already. These cheap copies are clearly unfit for the purpose of battery charging. Moreover unlike Honda they don't work with Victron inverter/chargers either so it seems the quality of their output just doesn't compare with Honda, quite apart from their poor general reliability that you report.

 

regards

Steve

Edited April 23, 2007 by anhar

[NB Alnwick]

There's one answer Graham. Honda. But you probably know that already. These cheap copies are clearly unfit for the purpose of battery charging. Moreover unlike Honda they don't work with Victron inverter/chargers either so it seems the quality of their output just doesn't compare with Honda, quite apart from their poor general reliability that you report.

 

Yes, that is certainly the conclusion that we are working round to!

[John Orentas]

Yes, that is certainly the conclusion that we are working round to!

 

 

These things are produced in the millions, if particular inverters or whatever won't work with them I would say it was more logical to say the problem was with the inverter.

[blackrose]

Incidentally how are you going to store a heavy beast like the EU30is on your boat, compared with the smaller model you have now?

 

That is certainly an issue. I had the EU10i securely locked and out of sight in an external locker. The EU30i will have to stay on the bow deck and I'm going to chain it to the boat. I was thinking about a short (2ft) section of heat resistant concertina type rectangular section vent hose (if such a thing exists) to vent the exhaust over the side of the front deck well. Also I'm thinking about some sort of fold down locker arrangement to keep the evil-doers at bay.

 

This is all a slight headache, but probably not as much as the installation of the Northern Lights diesel generator I was going to buy. I spent quite a long time talking to the distributors about how to cool it - dedicated skin tank vs mud box. It all involved a lot of work and I'd be interested to hear what other inboard deisel owners did.

Edited April 23, 2007 by blackrose

[Cafnod]

I was not suggesting that a petrol engine suffered from running at light loads, it just seems pointless running a larger set if you do not need anywhere near its output, that is why, until recently I owned several gensets. A 4kw set that happily ran a 9 inch grinder, Hitachi 9 1/4 inch circular saw, 1800 watt router and similar large industrial power tools. A lot of the time I was using these I was running lighting as well.

However if I were just going to be running a 600 - 900 watt electric drill or a jigsaw plus some lighting then I would take along my old 1600 watt unit that really belongs ing the science museum.

Both of these are Hondas and both have run faultlessly for many years. The 4kw set was recently sold on this forum and I demonstrated it on delivery and have not heard back from th buyer.

I have always used gensets sized to my needs. I cannot see the point in incurring the expense of running a large set for small loads.

For 12vdc battery charging I used to use a dedicated DC Honda unit that switched between 6/12/24 vdc. It ran for hours on a litre of petrol and did an admirable job. I have recently sold this too, pending collection.

What we now have is a 10hp Ruggerini single cylinder diesel which is raw water cooled. This drives a good quality 3.8kw 240vac alternator and a large 12vdc alternator.

I will use this genset for both charging batteries and running mains equipment when we will be moored somewhere for a few days and our domestic batteries may become depleted.

Installation of our dedicated genset. Channel section steel bolted to the longitudinal engine members and bolted to welded brackets on the swim plate. then two longitudinal members between these inverted L's with spacers and drillings to take the genset mounts (4 off, rubber).

I used a filtered bronze fitting with a sea cock. A skin tank would have been far too much hassle and a mud box not necessary for the volume of water. There is a exhaust alarm on the engine if water stops flowing. On the outlet side the cooling water is injected into the exhaust manifold at the genset engine end and the resultant mix goes down a 50mm exhaust hose to a Vetus waterlock, then to a Vetus silencer and out to the world via a 5omm hose tail skin fitting.

As the old loom had been cut I made one up using 8 way multiblock connecters and 2.5mm tri rated cable. That goes to the control panel inside the boat.

Apart from plumbing the beast for diesel, for which we acquired an 18 gallon s/s tank the only other thing was to fit a stop cable on the outside control binnacle.

All inall about 2 1/2 days work.

[blackrose]

The Honda EU range all have an Eco function which is meant to economise on fuel when running lighter loads and I want the flexibility to run whatever I want within the rated load of the generator. I have a 1.6kw washing machine, which could have been run off a EU20i, but then that would probably be all I could have run. With my EU30i I will be able to run the battery charger and some other appliances like the TV at the same time which makes sense to me.

[John Orentas]

What we now have is a 10hp Ruggerini single cylinder diesel which is raw water cooled. This drives a good quality 3.8kw 240vac alternator and a large 12vdc alternator.

I will use this genset for both charging batteries and running mains equipment when we will be moored somewhere for a few days and our domestic batteries may become depleted.

I used a filtered bronze fitting with a sea cock. A skin tank would have been far too much hassle and a mud box not necessary for the volume of water.

 

 

 

If your main engine is keel cooled why don't you use the same tank for both engines, shouldn't be a problem.

[Cafnod]

Because the water cooled exhaust is quieter than a baffled or absorption silencing system. If I need to run the genset near other boats I want it to be as quiet as possible. It was much less hassle to keep the raw water cooling than to modify the genset.

[blackrose]

If your main engine is keel cooled why don't you use the same tank for both engines, shouldn't be a problem.

 

That is a possibility I discussed with two suppliers when I was thinking about an inboard deisel generator. The first (Paguro - Advance Yacht) recommended this 'closed loop' system rather than bringing in raw water through a mud box, but the second supplier (Northern Lights) said that because one engine would always be higher than the other, sharing the same skin tank meant that there would always be problems with getting air out of the system. I didn't really understand why you couldn't have a header tank above the lot, but he seemed to think it wouldn't work.

Edited April 26, 2007 by blackrose

[StoneHenge]

The solar panel will cerainly help and can be made much more effective if you angle it to be at right angles to the dirtection of the sun. that could meen continually adjusting it though the day but tilting it up to 55 degrees or so and pointing it south will make a big difference.

 

Nick

 

Thanks. We built a stand for it. Not worth paying a tracking device, but I am not bothered about shifting it round a bit every couple of hours. It rests at about 45/50 degrees and at best output for a 60w panel we were getting around 53 so not bad really. It will certainly help with some of the charging anyway, regardless of where we end up mooring.

 

Interesting discussions about the genny's and LPG conversions. The honda is sounding like the 'one' at the moment. Will look more into it when we come to start needing one.