Choosing a good generator

softdown · October 2019

garynappi said:

Having gone through many hurricanes and long term power outages and living in south Florida I couldn't imaging being reliant exclusively on solar. Being on my fourth genset (once upgraded from small one, second (fairly cheap 4kw model) burned out on long term power loss, third lost in divorce) My current one has taken me through three long power outages running TV, refrigerator, well pump, clothes washer / dryer (all 220v stuff was resource balanced not run all at once), and two 6000 BTU window shaker AC units. I stayed comfortable and sacrificed nothing but a bit of load balancing and fuel runs to fill my five 5 gallon jerry cans every 4 or 5 days.

Disadvantages of a Genset are;

1.Fuel, 2. Noise, 3. Reliability

Fuel availability has been mostly been negated by Florida statutes (526.143) requiring fuel stations to have backup power.
Noise? tough nuts, the noise is worth it.
Reliability? Get a genset with a Honda motor, start it regularly, store with gas conditioner no problems.

Advantages of a genset:

No worries about code and regulations and grid tie issues.
Ability to power most anything in your home (depending on genset size) and not worry whether / or when it can be done
Works at the same efficiency post storm in sunny or cloudy and rainy conditions
No issues with batteries.
Many "kits" are available for gas gensets to run on propane or natural gas too.

My experiences with gensets are... those ~4.5kw are not very happy running (serially) clothes dryers, pool pumps, and hot water heaters. 4.5kw will do it but they complain loudly :-) So, my last 2 were 8.5kw. I can run all day on mine with a bit over 5 gallons of gasoline, and sleep with it off. Solar / batteries can run my fans and exterior DC lighting at night.

Larger than 8.5kw or so, fuel is a bigger issue.Getting to the fuel and bringing enough of it back home is a pain. I'm not saying a genset over 4kw is some sort of de facto standard, just what I find that works for me. My dad who lived upstate New York always had a 4kw genset and never had an issue with enough power. His refrigerator, well pump, 8k btu window shaker, TV, and satellite were all he needed for his little farm house to be comfortable.

Oh, I keep my genset running cooler (and fumes away from the house) by plugging a small table or squirrel cage work fan into the genset. and blowing on it and placing it under the shade of a tree. I'm fairly certain the reliability and lifetime of the genset is improved under these conditions.

Worth it to procure ethanol free gas for genset usage. The years fly by. I've posted a link to national sources of ethanol free gasoline. I'd link it but trying to get some errands run.

Dave Angelini · October 2019

Lorrenzo did form off Africa, is not in the north atlantic, and the water in the central Atlantic is warmer than usual this year. No conspiracy just fact. How much do you want to bet and do you have a Paypal?

https://earther.gizmodo.com/hurricane-lorenzo-sets-record-as-strongest-storm-on-rec-1838604479

Estragon · October 2019

Looking at the pic, my guess is it was birthed normally, but is getting sucked off the normal east/west path by the intense looking low off Labrador.

softdown · October 2019

I had the impression they were telling us the Atlantic was now so warm that it developed in between Europe and the US. Which I thought - BS. The first picture didn't show where it had originated and traveled from.

Its a make hurricane anyway - aka: himmicane. Give it a couple beers and a cigar.

mike95490 · October 2019

here's the link for gas stations I have: https://www.pure-gas.org/index.jsp?stateprov=CA I use aviation gas from the airport, has 1 year stable life, no ethanol.

softdown · October 2019

mike95490 said:

here's the link for gas stations I have: https://www.pure-gas.org/index.jsp?stateprov=CA I use aviation gas from the airport, has 1 year stable life, no ethanol.

Interesting that they use lead in aviation gas - they are reportedly trying to get away from that. It would be cheaper and more effective, I think, to use ethanol free gas with PRI-G. That combo might last 10 years under proper storage. For me - the years simply fly by.

BB. · October 2019

For older aviation (and other motors) the lead in fuel was a lubricant. Would have problems with low lead and lead free fuel.

Friend of mine nearly did not get to the nearest airport over the Rockies when a valve seized in his old Moonie during the switch over to low lead aviation fuel.

Bill

softdown · October 2019

Never said the switch would be easy. Or that they didn't have good reasons. Mooney's are cool planes. I did a Mooney transaction during my very short career of buying/selling airplanes. It didn't look like the airplanes at www.mooney.com either. Wondering what happened.

mike95490 · October 2019

Aviation gas is heavily regulated by the FAA to insure that all the plane engines in operation, are compatible with the fuel. Getting a new engine design approved and allowed for retrofit is very expensive.

softdown · October 2019

Considering that almost all cars used to run on leaded fuel, I tend to doubt that leaded avgas is a huge problem. We have done a pretty good job at cleaning up the emissions from the gorilla in the room - cars and trucks. Though I rail at some, perhaps many. of the more recent measures taken to placate the EPA.

solorone · October 2019

With 36 years of off-grid, I have a bit of Genset experience. For myself, I have found the Generac brand to be the best bang for the buck and I stay in the $500 to $750 range. It has good waveform, has been incredibly reliable. Parts are handy online, warranty work (I have never needed) is convenient. I stay in the 6KW to 7Kw range. I recently bought a Generac GP 5500, Consumer Reports the best model a couple of years ago, for $370 with 28 hours on it as a spare, it can power out 150A charge on my Xantrax. Drained it and packed away.

Now I have been down the HIGH-END generator road and found it a disaster. Tried Kabota. Paid enough to buy 5 or 6 Generacs, and this does not include the upkeep and proprietary Kabota gold plated parts, 84$ for 2 drive belts that often needed replacement, not to mention the cost of diesel fuel.
Just my .02 worth, If you live in the southeast, good prices can be found about 7 months after a bad hurricane season.

solorone · October 2019

softdown said:

I had the impression they were telling us the Atlantic was now so warm that it developed in between Europe and the US. Which I thought - BS. The first picture didn't show where it had originated and traveled from.

Its a make hurricane anyway - aka: himmicane. Give it a couple beers and a cigar.

Yes, Lorenzo now holds the record as the quickest CAT5 to develop that far from the US. It's cat 5 life was very short-lived. Here is a good link I have been using since he started. Mike got a huge write up in State Florida paper this week, about his work. he has made several calls on canes that, though different than the NHC proved right. For Southeastern US weather info he can not be beaten. Mikes Weather Page, online or FaceBook.
https://spaghettimodels.com/ https://en.wikipedia.org/wiki/Hurricane_Lorenzo_(2019)

Trukinbear · October 2020

Say what you will about Briggs and Stratton but I've got a Troy Bilt 5550 that served as my backup generator until we lost power and became off the grid. We ran her for days on end until we realized our situation wasn't temporary - loud as hell, and thirsty but today with three-year-old gas in her she'll fire up on the 2nd pull of the starter - often the first.

We bought a Champion LPG inverter generator that after about 4500 hours burn't a valve - Champion ended up sending us a new unit but that was three months later. In the meantime, I bought a $50 25-year-old Onan RV generator, which I dolled up an mounted on a cart with LPG tank, and muffler with the remote push button start - I sold that for $1900 after using it for six months, and bought an Onan 7.5JB also in LPG we used for a year. That (plus we sold the replacement Champion) sold for enough money to buy 3 old Diesel Onans - one of which I used for over 4000 hrs, then I fixed them all up and sold them for enough to buy the generators in my signature - one had 20 hours, and the other had 38.

Gas is hard to handle, and doesn't keep long - after a disaster, you might have to wait in line for hours to get 5 gals of gas. Propane is good if you can get it delivered, lasts almost forever. Natural gas is usually a mistake - after Hurricane Andrew, the power was out for 6-7 months, the natural gas was out for a year. Diesel keeps with some additives, and if you can get it delivered is a great fuel - plus diesel generator lasts for a lot longer unless you buy one of those Chinese ones. We can't get propane delivered, but we can get off-road diesel delivered to our door for $1.50 less than you'd pay at a truckstop for off-highway fuel, and I LOVE my Kubota powered (and Hatz) Onan generator(s).

Riley · October 2020

swmspam said:

Re: Choosing a good generator

My batteries can easily consume several kW without breaking a sweat. The generator will be used for bulk charging to 80% SOC. My batteries have approximately 90% average charge acceptance efficiency between 0% to 80% SOC. The charge efficiency degrades rapidly at higher SOC. So, when using a generator, the batteries will target 80% SOC. This is within the "bulk charge" region of the battery, which can easily accept constant-power charging of several kW without needing a power rolloff. This generator is intended to charge though an OutBack GS8048, using the generator AC input.

The generator will run 4-5 hours of constant-power operation at approximately 75% of rating. This is generally near the highest operating efficiency of the generator engine. Operating continuously too close to the rated power invites overheating or destruction of the alternator. Running a 6.5kW generator constant-power at 75% rated power yields 5kW. Assume half (2.5kW) of the average output will be consumed by loads (lighting, cooking, etc.). This is a rather liberal assumption. The other half goes to battery charging. Assuming the bulk-charge efficiency of the battery and the charger efficiency are both about 90%, this results in:

2.5kW * 90% battery efficiency * 90% charger efficiency = 2.025kWh per hour of battery charge

It would take 5 hours to charge the battery 10kWh, which is a reasonable charge rate for bulk charge. It would take less time if fewer loads were being used and more of the generator's power went towards the batteries.

Therefore, the usage profile of the generator is 4-5 hours of 5kW constant-power output at 75-80% of rating, probably once per day during occasional emergency or off-grid situations. 5kW / 75% derating = 6.6kW rated power.

The generator needs to be of sufficient quality to work when needed, which doesn't happen often. I know the Honda, Yamaha, and Subaru-Robin generators ($2000) are excellent. For occasional emergency purposes, are the Generac portable generators ($1000) reliable enough to count on? I could use that saved $1000 to retrofit to LED lighting and other efficiency improvements that have much more profound energy consumption benefits.

Note: Regarding maintenance, regular oil changes are mandatory. I looked at an oil sample from my Yamaha EF2000iS with a material analysis microscope. The sample contained a slew of metal particles and shards. Obviously, the engine sheds bits and pieces during break-in and running. These bits end up in the oil, which is circulated through the machine, carrying the particles with it. Use a magnetic dipstick and change oil frequently! Otherwise, these particles will grind up your engine. The Generac incorporates an oil filter, which should help this.

Thanks for the well thought comment. I am sort of a new visitor here (back after a couple of years probably). I was brought back by my need to research generators for my off-grid cabin (my old Onan CCK just failed). I am trying to find a decent quality propane powered generator in the 6.5KW to 14KW range (240VW).

From my reading on the web and talking to a few people, I am nervous about the reliability of almost everything out there. Looking at Kohler, Winco, Honda, Cummings (Honda doesn't make a propane set and it needs some enclosure for semi-prime use).

Do you have any favorites that a guy could count on for 500 hours a year and last 10 years?

mike95490 · October 2020

> Do you have any favorites that a guy could count on for 500 hours a year and last 10 years?

Lister used to make some single and twin diesels, but they were not as efficient and repairmen could not count on them for lunch money (super rugged and reliable, used in lighthouses when they were electrified)

Otherwise, look for something with an oil filter and buy a pair of them, so you have a backup for the backup. They both start on a sunny day, but in foul weather, eventually, if you only have one generator, it will fail on you.

BB. · October 2020

Very roughly, the average speed of a mixed used car is 35 MPH (I have actually confirmed with my GPS over many years of driving).

500 hours * 10 years = 5,000 hours
5,000 hours * 35 MPH (fixed engine vs car engine conversion) = 175,000 Miles (rough equivalent) to car operation

That is a lot to expect from a simple genset--Especially ones that are splash lubricated and no oil filter. Changing oil every 100 hours is to an oil change in a car every 3,500 hours (vs 5,000 to 7,500 miles for average car these days).

Expecting >2,000 hours from a Honda genset is pretty much a given (good maintenance, nothing else "fails"). And one poster here got >6,000 hours on a small Honda eu1000i (900 Watt generator). Still ran, but a bit harder to start and smoked a bit.

Some of the gensets have failed for other reasons (the flex coupling on my old Generac was known to fail in even as little as 500 hours).

Get one genset that is "high quality" and a second genset that is good enough for backup? One suggestion I have made is get one smaller genset (very fuel efficient). And a second larger genset for backup and full loads--Such as battery charging in winter (fuel usage is not as critical for short runtimes; also large genset for power tools/shop tools/when needed).

Gasoline (and propane/natural gas) gensets are most efficient in the 50% to 100% load range. Below 50% loading, fuel flow does not drop much below 50%.

The inverter generators--They are nice for when you have longer periods of running at less than 50% loading (in eco-mode, generator engine slows down and the inverter keeps output at 120 VAC and 60 Hz).

There are many companies out there that make propane conversion kits. Hutch Mountain seems to have a good variety, and lots of videos on how to install them. Most (all?) of there conversions are bolt on in front of the carburettor. And they will still run from gasoline when needed). I have not used any propane conversion system--So I cannot answer how well they work--But they are pretty cheap to try (it seems):

https://www.hutchmountain.com/
https://genconnexdirect.net/
https://www.doityourselfrv.com/generator-conversion/ (genconnex seems to be a full Propane conversion, gasoline no longer supported)

https://www.youtube.com/watch?v=yaOqSO99GBY (video of customer conversion genconnex--very detailed)

I do not know anything else about the above links/products... Just a starting points for your searches.

Propane will reduce genset maximum output a bit... Burns cleaner. Propane is less BTU per gallon vs gasoline--So, you will need more "gallons" of propane storage for generator vs gasoline.

You are looking for larger gensets--But I would still figure out your minimum loads you need to run your home on. A 7 to 14 kWatt genset will burn a lot of "excess fuel" if you cannot keep it loaded >50%... I have run 2x full size refrigerators, a full size upright freezer, and a koi pond on a eu2000i (Honda) for 4 days during a California power outage....

Fuel costs (and fuel availability at times)--And for me, fuel storage (grid tied and just emergency backup power). My GT Solar works fine when grid is running, but no available solar power when utility power has failed.

I guess you are up somewhere in BC Canada... So gensets are hard to avoid during winter. The propane conversion kits all seem to need a big of priming to start--So autostart is a bit more complex. Also, running large gensets from propane--You need a relatively large propane tank to vaporize the liquid--And in cold climates, smaller tanks (with larger gensets) can get so cold, the liquid will not vaporize (there are charts for genset size/temperature/tank sizing).

The newer / hightech gensets out there (high tech sort of disqualifies many of the Hondas) will have remote start with auto-choke (or fuel injection)... Many of the Hondas have a manual choke (and they do need choking).

Is there anyone in your area that you know that is happy with their present genset and fuel choices?

-Bill

New_Mexico_Will · October 2020

I've been looking at generators for quite a while. I've always liked Honda, but their generators are virtually featureless. The best bang for the buck that I've found in a name brand generator is Westinghouse. I'm looking at the WGEN5300DF. It has remote/electric start, recoil backup, runs on gas or propane out of the box, transfer switch ready, 120/240 volts, automatic low oil shutdown, built in voltage regulation and overload protection all for under $600. It's 9db louder than a comparable Honda, which I can definitely live with.

https://www.lowes.com/pd/Westinghouse-WGen-6600-Watt-Gasoline-Propane-Portable-Generator/1002490218

Riley · October 2020

BB. said:

Very roughly, the average speed of a mixed used car is 35 MPH (I have actually confirmed with my GPS over many years of driving).
500 hours * 10 years = 5,000 hours
5,000 hours * 35 MPH (fixed engine vs car engine conversion) = 175,000 Miles (rough equivalent) to car operation
That is a lot to expect from a simple genset--Especially ones that are splash lubricated and no oil filter. Changing oil every 100 hours is to an oil change in a car every 3,500 hours (vs 5,000 to 7,500 miles for average car these days).

Expecting >2,000 hours from a Honda genset is pretty much a given (good maintenance, nothing else "fails"). And one poster here got >6,000 hours on a small Honda eu1000i (900 Watt generator). Still ran, but a bit harder to start and smoked a bit.

Some of the gensets have failed for other reasons (the flex coupling on my old Generac was known to fail in even as little as 500 hours).

Get one genset that is "high quality" and a second genset that is good enough for backup? One suggestion I have made is get one smaller genset (very fuel efficient). And a second larger genset for backup and full loads--Such as battery charging in winter (fuel usage is not as critical for short runtimes; also large genset for power tools/shop tools/when needed).

...snip...

Is there anyone in your area that you know that is happy with their present genset and fuel choices?

-Bill

Thanks Bill, Good insight into the generator hours verses car miles analogy. I am pretty well only charging my battery bank so always running at 50% or more but depending on the size of the generator.

I have talked to some of the locals including one of the local dealers/repair shop. The Cummins/Onan seem to be failing a lot and are tossed out after a few years. I do think people are running them hard and in very cold conditions. Not great for a cold generator to be hit at 80% load when cold...

One expert that I met online sells and repairs off-grid generators recommended one of the Kohler models (12RES) and thought it should easily run for 5000 hours if well taken care off. The other route I am considering is paying extra for a commercial / industrial water cooled generator running at 1800 rpm instead of the 3600 rpm screamers. Problem is that they are 3X the price and likely harder to get service for (less common).

I do have a backup generator (that's what I am using now). I just need to figure out what to do for my primary generator. I do know my loads which is primarily charging batteries and that requires about 5KW. Add 2KW I get 7KW. then need to derate the generator to improve lifetime and that's how I get to about 12KW. I could charge down at 3KW and that gives me 5KW or even less if I pay attention to what I run when charging.

I am finding it difficult to find serious people that are 100% off-grid but those that do, are running older 1800 rpm diesel generators. Expensive and they stink.

BB. · October 2020

That is sad to hear.... Cummins/Onan always seemed to be the gold standard for many decades.

One person used a 150 Watt or so flood lamp in an enclosure--Turn on the lamp about 30 minutes before starting (this was a Honda 4000sx gasoline genset) to ease of starting (and preheating the oil). The 150 Watt 1/2 hour draw on a larger battery bank was not usually an issue.

I wonder if modern synthetic oils help or hurt with engine life (5W and even 0W oils now?). I have always broken in an engine (first 10 or 20 hours) with cheap oil, then fill with high quality dino oil or now--Trying synthetics. (I probably will be dead before I find out the answers).

-Bill

Ralph Day · October 2020

When I was completely off grid I sacrificed some amp hours from the battery to block heat the 10kw diesel genset. A bathroom timer used in case I forgot. My genset was old and needed some heat in the control box all the time, starting and running. I have a 60 watt incandescent bulb in the housing that's about 1' by 1' by 1' dimensions.

Ran the heater for 20-30 minutes before start then run the genset for 5 or more minutes depending on the ambient temperature. I'd just have to be sure that there was enough battery capacity to run the block heater to warm the genset to charge the battery.

And never trust "automatic" system control...Manual is safer.

Dave Angelini · October 2020

Quite a few of my clients up that way and in Alaska have switched to LFP. In doing so they have been forced to keep the batteries above 40F. In doing so there has been a benefit of keeping the genset in an enclosure or off the wall of the heated battery room. The insulated gen enclosure is open to the battery room with convection, or fans, or some fashion to keep the genny from being exposed to the cold weather.

The word is this is a very good thing for them. Me also as I do not hear these winter stories as often. Our Sierra mountains are still a month away from the possible start of winter. Still fighting fires here.The main Utility is shutting down power to the poor souls who depend on it.

Might be helpful in your long term solution to think about it a bit. Good Luck Riley !

AlexDykes · November 2020

I ended up getting a MultiQuip DA7000SSA3. It's the same engine as the Kubota 7kW with slightly better generator specs in a quieter enclosure. You can get it with or without a trailer which is handy. I ended up getting the trailer and dismounting it because the MQ trailer is a steal and I converted it into a small fuel transport trailer. The Conext inverters are just fine with the MQ's power output and the Kubota engine is an asset. I have the same engine in a number of other machines so I wanted the parts commonality. It's the smallest multi-cylinder diesel currently in production so its a little smoother than most of the other options I was looking at.

Dave Angelini · February 2021

Totally disagree Paul ! How long have you been offgrid? Thanks for sharing your article BTW.

mcgivor · February 2021

PaulWoodward said:

I guess this has some of the best collections for off grid generator. If you really want to have all the way power in your off grid journey, these are the best one.

The term solar generator is misleading, they should be referred to a an a portable energy storage system, (solar) if charged by PV, the ones in the link are suitable for camping, to charge phones, a laptop or a LED light or two but useless, for anything other than that. They definitely shouldn't be considered suitable for offgrid living.

BB. · February 2021

Paul was a Link spammer/SEO poster out of India. Gone.

Bill

mike_s · February 2021

(or years)

Dave Angelini · February 2021

Good Job Bill ! Saved me from thinking that it was easy to go offgrid with his generators.

JRHill · February 2021

mtdoc said:

Re: Choosing a good generator
Any opinions or advice on Briggs and Stratton engines in generators??

We bought a new B&S 8000 #30337 for the construction phase and for backup/charging afterward. The first thing I realized was it was quite a gas hog and loud. The crew who was doing the dry in had a Honda 3000(?) which died so I lent them the B&S. They ran it 2 days and the company owner said screw it and drove the 5 hour round trip to town to buy a replacement Honda as they were tired of making fuel runs for the B&S. It really was that bad in comparison.

After the construction phase and the solar was installed I readied it for connection to the VFX3648 inverter. I tested the connection and operation and the voltage regulator blew before I could disconnect it. It surged wildly. Fortunately the inverter was fine. I got the B&S fixed under warranty. When I got it back 6 weeks later I tried it again. Same thing but I got it disconnected in time. I did some checking and learned about the possibility of a bonded neutral in the B&S. Yup, sure enough. I found the bond and lifted it and it ohmed out as open. I tried it again. 2nd voltage regulator blew. Got it fixed again and was told there would NOT be another warranty honored after this. I kept trying but never did get the B&S to work through the Outback inverter. I was an expensive experiment.

After some other tests I ended up going with an EU7000is and think very highly of it. It has 1800 hrs on it and just sips the fuel. Only normal maintenance to date. And its quiet++.

Choosing a good generator

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