Choosing a good generator

Uncle Dave

Re: 48 Vdc or 120/240Vac?

oil pan 4 wrote: »

I have seen 1800rpm 6.5kw 3 cylinder Kubotas with thousands of hours running less than 2kw load.
None burned excess oil.
The big 70kw 400Hz generators I work on run at 5kw or less pretty much all the time. Only the 2 stroke Detroit diesels burned oil, because they are historically known as oil burners, these particular ones had been improperly rebuilt several times by the lowest bidder. The new generation of 4 and 6 cylinder Cummins have yet to burn much if any oil and get ran the same way.

I say get something that turns at 1800rpms, liquid cooled, gas or diesel. 1800RPM generator sets (4 pole generator) will be a lot quieter and burn a lot less fuel than a 2 pole, 3600rpm screamer.
Liquid coolant means you can pipe what other wise would be waste heat some where and actually do something with it, especially during the winter.

That pretty much mirrors my experience.

Ive never had an 1800RPM Rv type liquid cooled diesel genset "wet stack" - after thousand of hours of light loads.

Currently own three

Onan (kubota ) 10K in Rv1 - 4500 hours
Power Tech 8000 (Cat 3011C Perkins Shibura/Perkapillar) in my RV2 - 1205
Onan (Kubota) 8000 RVQD variable RPM 8KW diesel inverter Grooming Van-1700 hours

softdown

Re: 48 Vdc or 120/240Vac?

Wow....what a thread. Thought I'd toss in my .02 since I use eight different generators over the past four years. Subaru is good. New Briggs & Stratton is not so great. They are not designed and built for years of hard use. Old Briggs & Stratton were simple but they keep chugging away. Kubota is good...and expensive. Just because an engine is a diesel doesn't mean that it is good. They make cheap, junk diesels too. Sometimes a quality name (in the past) will appear on a cheaply made genset. You generally get about what you pay for in generators. For those on a budget, I might recommend a used genset that likes to start. A very large number of problems are in the carb from gas, especially ethanol, that sat for a long time. If you can overhaul small carbs, you can buy used gensets for a song.

I think serious genset users benefit from having a small one and a larger one. I am surprised that nobody mentioned that you can use a couple big, preferably deep cycle, batteries with most 3500 watt, and larger, modified sine wave inverter and just use the generator to occasionally charge the batteries when doing construction. Running generators all day, for tool usage, used to cost me hundreds of dollars/month. Keep an eye on the oil and use a quality synthetic or, at least, oil approved for diesels. Run your gas through a filter screen when adding fuel. I had a small contaminant incapacitate my Subaru engine until the carb was gone through. Use good fuel stabilizers like PRI-G when the fuel will sit for months. Keep a few feet of 1/4" fuel hose handy if you are in the "boondocks". Turn off the fuel valve when leaving, or moving, the genset for awhile. Use 12 gauge extension cords for tools using over 12 amps of power. Use 10 gauge, next to the genset, for longer runs if you can. Lack of power is hard on motors. Overtaxing your genset is hard on the genset.

I hope these "tips" help out a few folks. Happy camping. After all, living off of the grid can be pretty close to camping unless you did things "right".

vtmaps

Re: 48 Vdc or 120/240Vac?

softdown wrote: »

I am surprised that nobody mentioned that you can use a couple big, preferably deep cycle, batteries with most 3500 watt, and larger, modified sine wave inverter and just use the generator to occasionally charge the batteries when doing construction.
<snip>
Lack of power is hard on motors.

Welcome to the forum,

Low voltage is certainly hard on motors, but so is modified sine wave power. I would not use modified sine wave on any construction tools. Even if you don't burn out the tools, you are being hard on them with modified sine wave power.

--vtMaps

oil pan 4

Re: 48 Vdc or 120/240Vac?

softdown wrote: »

I think serious genset users benefit from having a small one and a larger one. I am surprised that nobody mentioned that you can use a couple big, preferably deep cycle, batteries with most 3500 watt, and larger, modified sine wave inverter and just use the generator to occasionally charge the batteries when doing construction. Running generators all day, for tool usage, used to cost me hundreds of dollars/month..

That is why I built this. I put a full size AMG battery under a pure sine inverter on my electric start generator.
Since I am cheap I got this expensive pure sine inverter for $150, used but like new off ebay.
That way I don't have to run a 10hp 7kw generator just charge a cell phone or run a small drill.

Also to prolong life of a gas generator you can run add some 2 stroke oil to the gas.

techntrek

Re: 48 Vdc or 120/240Vac?

softdown wrote: »

...
I think serious genset users benefit from having a small one and a larger one. I am surprised that nobody mentioned that you can use a couple big, preferably deep cycle, batteries with most 3500 watt, and larger, modified sine wave inverter and just use the generator to occasionally charge the batteries when doing construction...

Welcome to the forum.

Yup, those 2 things have been discussed at times on the forum, I'm a little surprised if they weren't mentioned in this thread but there have been other threads.

Personally I use a large genset for my electric WH and well pump, and a small inverter-genset for the baseline loads (emergency power).

Also at one point I had a 22 kw battery bank when I only had the big genset, and used it to run the whole house for most of the day, only running the genset for a few hours in the morning and night for showers and to charge the batts. Later I switched to using my Prius as a battery + genset combo, paired with a 4 kw UPS as the AC source, see the link in my signature for details. The big genset costs about $5 per hour to run, the Prius costs about $8 per day.

softdown

Re: 48 Vdc or 120/240Vac?

vtmaps wrote: »

Welcome to the forum,

Low voltage is certainly hard on motors, but so is modified sine wave power. I would not use modified sine wave on any construction tools. Even if you don't burn out the tools, you are being hard on them with modified sine wave power.

--vtMaps

I'm sure that 10 off gridders will have about 10 opinions on this. Tool motors are generally ok with modified sine wave. It is the sensitive electronics such as televisions and computers that usually need pure sine wave. Generators do not put out pure sine wave energy unless their inverter does it for them.

This is an off grid forum right? So it is generally going to be inverters or gensets. I'd hate to use a $3000 pure sine wave inverter the way that I have used my much, much cheaper inverter. I'd also hate to have it stolen like my 5000 watt inverter was. Pure sine inverters also use about 10% more energy to run...as a rule.

It is good to see other opinions and experiences of course. That is simply my experience and understanding. I couldn't be further from being an EE if you shipped me to the moon.

Cariboocoot

Re: 48 Vdc or 120/240Vac?

softdown wrote: »

I'm sure that 10 off gridders will have about 10 opinions on this. Tool motors are generally ok with modified sine wave. It is the sensitive electronics such as televisions and computers that usually need pure sine wave. Generators do not put out pure sine wave energy unless their inverter does it for them.

Nope. Popular misconception.
Any good electronics will be sensitive to bad power input and as such will have a really good power supply to clean it up. Cheap junk may rely on your grid power being spot-on-spec but the smart designer knows better. Even grid power can have THD up to 5% or even worse if the utility doesn't care.

Meanwhile motors are just motors. There's a limit to what you can do with the design in any practical sense, so they are subject to the quality of the power they receive. If that is high in distortion or off frequency or Voltage they will suffer. It may not be instantaneous and it may not cause irreparable damage, but it will suffer.

One problem comes from the fact that whereas there are standards for pure sine wave there are none for the vague "modified sine wave". MSW may hit proper RMS Voltage, but it can do it with anywhere from one to hundreds of increments with any amount of time at each level, no assurance of peak Voltage, and no smoothing of spikes. In short one MSW inverter may put out a waveform very close to sine while another MSW inverter is just a square wave. Since you never know exactly how any particular device will react to what kind of off-spec power you end up gambling both ways.

In fact standard generator do put out sine wave, it's just that it can vary quite a bit as the specifications are held as a function of engine speed and when that inevitably varies so does frequency and Voltage. But the waveform tends to be very clean.

This is an off grid forum right? So it is generally going to be inverters or gensets. I'd hate to use a $3000 pure sine wave inverter the way that I have used my much, much cheaper inverter. I'd also hate to have it stolen like my 5000 watt inverter was. Pure sine inverters also use about 10% more energy to run...as a rule.

It is good to see other opinions and experiences of course. That is simply my experience and understanding. I couldn't be further from being an EE if you shipped me to the moon.

No one wants anything stolen except thieves.

Yes, the forum is at least in part about off-grid systems but also grid-tied. In both situations we often talk about and recommend generators. You'd be amazed at how many people find that weird! It's a solar forum, right? So why do we talk about generators? Why aren't we just telling everyone to buy lots and lots of PV and save the world?!

'Cause it's also a practical forum and the best solution is not the same one for everyone.

BB.

Re: 48 Vdc or 120/240Vac?

Regarding motors, there are different types of motors. Brushed or "universal" motors--Should run fine on MSW or TSW inverter.

However, induction motors (single phase, various capacitor types, 3 phase motors, etc.) can run upwards of 20% losses due to MSW inverter wave form.

Basically, the motor electric field is supposed to be a 60 Hz (or 50 Hz) rotating field that rotates "in phase" with the motor's "rotor". Basically, the inverse of an AC generator's output voltage profile.

MSW wave forms have not only the fundamental voltage wave form (the 60 Hz sine wave), they have additional sine waves at higher frequencies. Because these frequencies are not in phase with the rotation of the motor, they simple move "extra current" through the windings and the rotor that does no work... That extra current is dissipated as heat or Power=I²R heating (and some other secondary effects).

So if you have a motor that is running near its temperature limits on TSW power/utility power (refrigerator compressors, water pumps, etc.), the extra heat will cause shorter motor life (engineering rule of thumb, for every 10C increase in temperature, 1/2 reduction in life--for pretty much anything).

For transformers, the extra frequencies can cause "circulating currents" in the transformer cores--And increased heat/losses.

In electronics, MSW vs TSW is all over the map. Many "cheap/small" electronics use the TSW wave form as part of their circuit design to limit peak/average current flow. The "soft edges" of a fundamental sine wave means capacitors do not pass as much current (in circuits that use capacitors to limit current flow) and for many computer power supplies that have a diode rectifier that charges an intermediate high voltage capacitor (the sharp "zero to full voltage" edge causes high peak current flow through the diode/storage capacitor--And remember that heat is Power=I²R, so if you have 2x higher peak current, you have 4x more heating).

Many newer/larger/more expensive electronics are designed to work well on MSW and TSW wave forms (typically this are Power Factor Corrected Power Supplies--If you want to discuss the details further). I have done a little testing, you can try a Kill-a-Watt type power meter and measure the PF (power factor) of the AC devices--From my limited experiences, if the PF is ~0.95 to 1.0, they will work fine on MSW inverters, the poorer the power factors, such as 0.80 and below, the more heating will be caused by MSW wave form).

The problem is that something like 80% of the AC loads will work fine on MSW, and ~10% will not (can fail in minutes, hours, days of usage--You may notice smell of smoke/hot electronics/motor or you many not). Without trying, it is not easy to look at a device and determine to which group it belongs.

A nice article:

http://www.solar-electric.com/lib/wind-sun/Pump-Inverter.pdf

Note there is one detail that is glossed over (or wrong in the wave form drawing). The peak voltage of a TSW inverter is ~120 VAC * srt(2)=170 volts peak. On a MSW inverter, the peak voltage will be 10-20+ volt less:

http://forums.motorhomemagazine.com/index.cfm/fuseaction/thread/tid/26679704/print/true.cfm

This low peak voltage can cause issues with many electronic power supplies (computers, electronics, florescent lights, etc.). The low peak voltage of the MSW wave form can be too low for reliable conversion to DC output power (looks like a brown out condition).

Personally, if I wanted to run some cheap tools/electronics in an emergency, MSW is fine. However, if I was off grid full time and in a remote location--I would shy away from MSW.

-Bill

softdown

Re: 48 Vdc or 120/240Vac?

Academically, this makes great sense. Now let us look at a common real world scenario. Frank and Maggie want a home in the boondocks with no power within miles. Frank has been a carpenter and reckons that he can build the place with help as needed. Frank is going to use a lot of 12 and 15 amp tools, especially the air compressor. The starting surge requires up to 40 amps of power with many tools. If they don't get it, their life span suffers appreciably.

So Frank and Maggie are left with a couple choices. They can run an appropriately sized genset all day and every day. Thus interrupting their peace and quiet, wearing out the genset, no doubt inhaling carbon monoxide here and there, and spending hundreds/month on fuel. I did that scenario for two years. They can buy at least a 2500 watt pure sine wave inverter, with incredibly surge capacity, and hope that it doesn't break or get stolen. It isn't going to like it much when the batteries get low either....I think. Cost of that inverter? Plenty. They can buy a big modified sine wave inverter for a few hundred dollars and keep their fingers crossed for their tool longevity. Put the three options up for vote and see who wins? Looks like a coin flip to me.

My genset repair guy has taken EE classes and says that MSW is probably a better signal than my 70's vintage Briggs & Stratton gensets put out. He has seen plenty of my gensets and a few others. On the other hand, I know another electrical wizard that swears by the quality of genset power....seemingly no matter what. Guess I wonder why they install expensive pure sine wave inverters on many Honda and Yamaha gensets if the power signal is so good.

Been mostly cloudy this week and listening to one of my quietest gensets yammer away is making me yearn for the comparative peace and quiet of the city. Anything less than a 15-20 amp charge isn't going to get much polite attention trom my battery bank. So I need to run a 2500 watt, or better, genset for hours at a time.

Just my .02. I'm here to learn and, hopefully, to help. Besides, my llamas are not much in the way of company.

BB.

Re: 48 Vdc or 120/240Vac?

It takes a lot of copper and iron to supply lots of current with a good sine wave voltage, along with good a good automatic voltage controller.

Given that many battery chargers and electronics take high current spikes during peak sine wave voltage (poor power factor), can cause the sine wave peaks to collapse/distort.

Use a quiet/small inverter inverter generator for lights and charging battery power tools. Fire up the larger genset to run compressor/large saws/etc.

Use the battery+inverter (+solar if you want) for evening/overnight power (with a small 300 watts inverter if you can get away with it].

-Bill

westbranch

Re: 48 Vdc or 120/240Vac?

My genset repair guy has taken EE classes and says that MSW is probably a better signal than my 70's vintage Briggs & Stratton gensets put out. He has seen plenty of my gensets and a few others. On the other hand, I know another electrical wizard that swears by the quality of genset power....seemingly no matter what. Guess I wonder why they install expensive pure sine wave inverters on many Honda and Yamaha gensets if the power signal is so good.


FYI, The Honda inverter sets make 3 phase AC, converts it to DC, and then back to AC to get that Sine Wave so smooth....that is what allows for the reduced speed when not under load.... This from the former electrician that owns the Honda dealership here...
at lest

Cariboocoot

Re: 48 Vdc or 120/240Vac?

softdown wrote: »

My genset repair guy has taken EE classes and says that MSW is probably a better signal than my 70's vintage Briggs & Stratton gensets put out. He has seen plenty of my gensets and a few others. On the other hand, I know another electrical wizard that swears by the quality of genset power....seemingly no matter what. Guess I wonder why they install expensive pure sine wave inverters on many Honda and Yamaha gensets if the power signal is so good.

A generator that has an inverter on it is not the same at all as a standard generator. The inverter-generator is not a standard gen with an inverter attached to improve output. The design is quite different.

Inverter-generators are able to output steady Voltage and frequency against varying loads while also allowing the engine to run slower or faster as needs demand. A standard generator has to run at a fixed RPM at all times to maintain V & F regardless of load and so burns more fuel at lighter loads than an inverter-generator of the same capacity will.

And as I said before the waveform on a standard gen is pure sine but it distorts if the load changes cause the engine RPM to shift. On the other hand the I-G design has less rotating mass and so a lower surge rating than a standard gen of the same size.

Your genset repair guy is wrong about the quality of MSW. A standard gen can only output sine wave: it is the nature of the design. Magnet moves past coils, Voltage ramps up as the magnet centers on coil, ramps down as it moves away. It is an analog function of mechanical motion. North pole goes past current moves one way, South pole goes past current moves the opposite way; Alternating Current. Speed of the spinning magnet = how often the change in polarity = frequency of the AC waveform.

oil pan 4

Re: 48 Vdc or 120/240Vac?

My cars alternator makes 3 phase too.
You want 3 phase for generation because it takes 11% less torque to generate the same power with single phase.
In same size applications that means the 3 phase uses less fuel and could use a smaller engine. But with real direct drive 3 phase inverterless generator sets you typically don't see them any smaller than about 10kw.

softdown

Re: 48 Vdc or 120/240Vac?

One of the significant challenges of living off grid is dealing with genset noise. Is there an affordable, high performance and quiet muffler available? May make a million dollars yet. But I tend to doubt it.

Cariboocoot

Re: 48 Vdc or 120/240Vac?

softdown wrote: »

One of the significant challenges of living off grid is dealing with genset noise. Is there an affordable, high performance and quiet muffler available? May make a million dollars yet. But I tend to doubt it.

An exhaust muffler is not all there is to making a quiet generator.

Some other things that affect the noise level:

1). RPM. 3600 RPM standard generators aren't known as "screamers" for nothing. 1800 RPM (commercial prime power units) or variable RPM (inverter-generators) are much quieter.

2). Mass. Cheap gens that have the bare minimum amount of whatever rattle and bang and in some cases even act as sound boxes and amplify the noise. Air cooled is noisier than liquid cooled, but guess which is cheaper.

3). Quality. Attention to detail in the design can lower the noise level. Gens have to move air to cool engines (even liquid cooled) and the moving of air makes noise. If they do a good job on the design this can be kept to a minimum.

So the quietest thing would be a well-designed and well-made heavy, slow-running, liquid-cooled inverter-generator. Unfortunately it would not come in under $1,000 per unit.

You should hear how quiet those old hit-n-miss engines were. And that without a muffler. A bit impractical these days with the wildly varying RPM and evaporative cooling. 600 lbs. of engine developing 3 HP is a bit too much.

Mangas

Re: 48 Vdc or 120/240Vac?

Cariboocoot wrote: »

A generator that has an inverter on it is not the same at all as a standard generator. The inverter-generator is not a standard gen with an inverter attached to improve output. The design is quite different.

Inverter-generators are able to output steady Voltage and frequency against varying loads while also allowing the engine to run slower or faster as needs demand. A standard generator has to run at a fixed RPM at all times to maintain V & F regardless of load and so burns more fuel at lighter loads than an inverter-generator of the same capacity will.

And as I said before the waveform on a standard gen is pure sine but it distorts if the load changes cause the engine RPM to shift. On the other hand the I-G design has less rotating mass and so a lower surge rating than a standard gen of the same size.

Your genset repair guy is wrong about the quality of MSW. A standard gen can only output sine wave: it is the nature of the design. Magnet moves past coils, Voltage ramps up as the magnet centers on coil, ramps down as it moves away. It is an analog function of mechanical motion. North pole goes past current moves one way, South pole goes past current moves the opposite way; Alternating Current. Speed of the spinning magnet = how often the change in polarity = frequency of the AC waveform.

Thanks Coot. Always wondered what the difference was.

Concur. On the larger gensets the 1800 RPM units run quieter than the air cooled screamers. Despite its size, my new Cummins Onan RS 20 kw unit is very quiet.

Sidebar, since I installed the new high efficiency HVAC system this year the genset hasn't run yet except for exercise. Better technology, more capacity.

westbranch

Re: 48 Vdc or 120/240Vac?

Mangas wrote: »

Sidebar, since I installed the new high efficiency HVAC system this year the genset hasn't run yet except for exercise. Better technology, more capacity.

Hi Mangas, do you have the make and model Of that HVAC?

Merry Christmas.

Mangas

Re: 48 Vdc or 120/240Vac?

Westbranch as follows:

Trane XC95m Modulating Upflow Propane AFUE 95%+ Efficient Furnaces and Air Handlers 3 Tons w/altitude kits (2)
Trane XV20i Variable Speed Air Conditioners and Compressors 3 tons 21 SEER (2)
Trane TZONE950 Digital Self Communicating Thermostats

So far these units appear to be significantly more efficient than the previous units evidenced by higher battery levels during prolonged inclement weather. Battery levels are where the rubber meets the road.

Back of the envelope, I estimate they are using at least 30%+ less energy than the older units. We'll see how reliable they are long term. Like anything else what's most important is who installs the system. Not cheap but looks like pretty good technology.

And a Happy New Year . . Let er' Buck!

techntrek

Re: 48 Vdc or 120/240Vac?

softdown wrote: »

One of the significant challenges of living off grid is dealing with genset noise. Is there an affordable, high performance and quiet muffler available? May make a million dollars yet. But I tend to doubt it.

Yes. I mentioned it in my last post. Way quieter than my Honda. Not just a muffler though. 8)

No, you can't add a muffler to a genset and expect it to be quieter - every attempt I've read doesn't go well.

westbranch

Re: 48 Vdc or 120/240Vac?

Guess it's hard to stop a Trane...:-) (couldn't resist)

from: http://www.hurlbutvisuals.com/blog/2012/06/its-hard-to-stop-a-trane-shooting-action-sequences/

Attachment not found.

mike95490

Re: 48 Vdc or 120/240Vac?

re: adding a muffler to a genset. You need to enlarge the plumbing, so you do not cause any more restriction then the factory setup, or else you burn valves. And the factory unit may have some sort of "resonator" in it to help scavenge the cylinder(s).

westbranch

Re: 48 Vdc or 120/240Vac?

Back in the early '70s as a nubile in the woods,at our 20 man crew camp, I saw an old diesel generator in an insulated power shed (R12 fiberglass) with the exhaust pipes going into the top of a 45 (55) gallon drum, buried in the ground a few feet, and another exit pipe aimed to the stars.

All one could hear was a faint boom boom boom , more of a vibration than the sound.. cheap, simple and effective.

john p

Re: 48 Vdc or 120/240Vac?

be very careful adding any non factory approved or fitted silencer or extra pipes to a diesel engine. They overheat quicker than gasoline engines do if restricted in a no approved way..

softdown

Re: 48 Vdc or 120/240Vac?

My 70's vintage Briggs & Stratton gensets are as noisy as the dickens. I was thinking the factory mufflers may be a bit worn out. That simply replacing them with new small engine mufflers may effectively reduce the noise level. But someone recently said that replacing genset mufflers has not enjoyed success.

BB.

Re: 48 Vdc or 120/240Vac?

Look at a modern genset--They can be much quieter and probably last longer too.

If you live in a residential neighborhood--I would not want to run any of the old generators in the evening/night--And probably not too much during the day too.

-Bill

techntrek

Re: 48 Vdc or 120/240Vac?

+1

......................

softdown

Re: 48 Vdc or 120/240Vac?

Remote on top of remote is where I live. My address "doesn't exist" according to "the system." Money is always tight...and I have several gensets. Each one carrying its own pros and cons. Over the past couple weeks, I enjoyed being able to leave an old Briggs & Stratton genset at a remote cabin while work was done. Big enough to do almost any job and the wheels allow convenient transport. Yet not attractive to many thieves.

Having said that, I am eyeing the Yamaha engine 2000 watt inverter gensets at Costco for $600. But I am also behind on some rental property taxes and that is a priority. 2014 was a financial disaster. One big event - blew up a 488 c.i. engine on a mountain pass hauling a 7 ton forklift at 4am. Ouch.

inetdog

Re: 48 Vdc or 120/240Vac?

softdown wrote: »

My 70's vintage Briggs & Stratton gensets are as noisy as the dickens. I was thinking the factory mufflers may be a bit worn out. That simply replacing them with new small engine mufflers may effectively reduce the noise level. But someone recently said that replacing genset mufflers has not enjoyed success.

With a cheap engine much of the noise comes from the valves and no muffler will help reduce that.

Also make sure that you do not create too much back pressure or you can destroy the engine.

softdown

Re: 48 Vdc or 120/240Vac?

I'm not sure that B & S gensets of the 70's were necessarily "cheap engines." Those "3300 watt" gensets cost about $450 in 70's currency. They seem to weigh twice as much. Sturdy, simple, and long lasting is how I see them.

I have a fairly new Onan Homesite 3500 with very little use. A little bit of snow melted and some drops landed on it while it sat idly. Has not worked since. A few drops of water would not phase the old B & S engines.

Complexity often equates to fragility. I'm not sure that true off gridders are well served with fragile electronics. Service guys seem to find ways to basically keep almost half of the stuff they are hired to repair.

BB.

Re: 48 Vdc or 120/240Vac?

Before you purchase that 2000 genset from Costco--See if you can find some reviews.

The last one that Cost sold in that class was from "Honeywell" (i.e., somebody paid Honeywell to use their name). The genset did not seem to run very long before there were more and more problems (and a mechanical replacement or so).

The Honda eu2000i is not cheap (somewhere around $1,000 delivered) these days... But they are relatively reliable for a small genset (2-6,000 hours of run time--500 hours can be typical for the "cheap" genset before something breaks).

Why many people end up with two gensets...

One small/quiet/usually more fuel efficient for day to day operations (battery recharging during bad weather, run a few AC items if the inverter/battery bank fails, etc.). A second (typically larger), noisy, perhaps easier to fix for 2nd backup power source and running larger shop/power tools when needed.

Becoming more of an issue as time goes on... Old stuff that was easy to repair and (for me) many times needed more fiddling to keep running. The newest stuff which is quiet and usually very reliable, but when it breaks is virtually impossible for tinkering type repairs and may not even worth repairing (replacing an inverter module, non-rebuildable engines, etc.).

Add that states like California are requiring significant redesigns/new gensets/off grid gasoline and diesel motors to comply with new smog control laws. And more regulations/permits/hurdles for (or against) backup gensets in many cities. Add reforumlated fuels (with lots of alcohol and/or other "Fuels", low sulfur diesel) that can play havock with small/older engines.... Make your picks, take your chances.

-Bill