Choosing a good generator

niel

Re: Choosing a good generator

well folks, i just stick this thread as it seems to be a good one and well worth 2nd looks as well as 1st looks for the membership.

westbranch

Re: Choosing a good generator

Never heard of diesel (oil) going bad in storage. Has anyone else?

FYI: My fuel tank for my backhoe still has 3 year fuel in it and the hoe does not suffer any issues running it.
I use winter fuel now that it is well below freezing ... down to -8 +- *C I run summer grade fuel.

ChrisOlson

Re: Choosing a good generator

Diesel fuel can get microbial growths in it (fungus and yeasts), and in certain circumstances become corrosive due to sulphate eating bacteria. It is best to treat it with a product like ALGAE-X or Bio Kleen if you intend to store it for over a year. The fuel itself does not deteriorate like gasoline does. But the growths in it can plug fuel filters and damage injection pumps and injectors (if corrosive from sulphides).

With the advent of ULSD, another problem crops up - once the wax in it settles out due to cold, it will not go back into suspension in the fuel when it warms back up. So a treatment like PowerService is necessary with ULSD if you will be storing or using it at temps of zero F or lower.

The third problem is water. Diesel fuel systems are sensitive to microscopic amounts of water that gasoline fuel systems and engines will tolerate with no problems. If the engine's fuel system is equipped with a water separator (most are), it is not usually a problem. But it only takes a half a cc of water to totally destroy the hydraulic head in a rotary injection pump (Roosa-Master, American Bosch, Stanadyne et al).
--
Chris

westbranch

Re: Choosing a good generator

Thanks Chris, I forgot about the algae...

unicornio

Re: Choosing a good generator

niel wrote: »

well folks, i just stick this thread as it seems to be a good one and well worth 2nd looks as well as 1st looks for the membership.

yes sir! ... this thread brings a lot in a crucial issue... very good decision, sr moderator! ...;-)

unicornio

Re: Choosing a good generator

ChrisOlson wrote: »

Diesel fuel can get microbial growths in it (fungus and yeasts), and in certain circumstances become corrosive due to sulphate eating bacteria. It is best to treat it with a product like ALGAE-X or Bio Kleen if you intend to store it for over a year. The fuel itself does not deteriorate like gasoline does. But the growths in it can plug fuel filters and damage injection pumps and injectors (if corrosive from sulphides).

Cris! ... Surely your culture on fuels come from the world of aviation? ... I have worked a few years with helicopters and control of the fuel tank is a daily work, first thing in the morning, before anyone fly ..... some water in a turbine is a ruin ...

am I right? ...;-)

Brock

Re: Choosing a good generator

Jumping back a bit. Chris in looking at that chart I don't see the big advantage of the inverter genset's everyone always mentions? Am I missing something, I would have thought I would see it at the 6 amp load, maybe thats not small enough of a load to see their advantage? Do you recall if either of the inverter genset were en eco mode or did you leave them running in normal mode?

Cariboocoot

Re: Choosing a good generator

Brock wrote: »

Jumping back a bit. Chris in looking at that chart I don't see the big advantage of the inverter genset's everyone always mentions? Am I missing something, I would have thought I would see it at the 6 amp load, maybe thats not small enough of a load to see their advantage? Do you recall if either of the inverter genset were en eco mode or did you leave them running in normal mode?

The advantage to an inverter-generator is in the over-all fuel consumption, not the fuel per kW hour. When the load rate drops the efficiency drops but this is made up for by the reduction in fuel consumed as opposed to running a fixed RPM generator at light loads.

Most important of all for any type of generator is to use the right size for the job. Even a 3kW inverter-gen will waste fuel if it's doing a job that could be handled by a 1kW one.

ChrisOlson

Re: Choosing a good generator

Brock wrote: »

Jumping back a bit. Chris in looking at that chart I don't see the big advantage of the inverter genset's everyone always mentions? Am I missing something, I would have thought I would see it at the 6 amp load, maybe thats not small enough of a load to see their advantage? Do you recall if either of the inverter genset were en eco mode or did you leave them running in normal mode?

Brock, they were in eco mode so they would idle down under lighter loads. IMHO, they did show some advantage at lighter loads. But under heavier loads I think it's just plain engineering - driving a little three-phase permanent magnet alternator that's probably no better than about 85-88% efficient, then rectifying to high voltage DC and converting back to AC in an inverter that's probably only about 88% efficient, can't match a conventional excited wound field generator. Too many conversion steps in an inverter unit.

I think their main advantages are that they are very quiet under light loads, can save some fuel under light loads, and the "suitcase" ones are handy to carry around. The main application for them is camping and outdoor activities where the generator rarely runs at full rated load. So they are ideal because you don't need a generator running at 3,600 rpm just to maintain freq for that. But for battery charging I think a conventional is more efficient being that the bulk of the power is delivered during bulk charging stage, and idling down during the final stages of absorb doesn't really save that much in comparison to the lost efficiency during the full load stage.

Keep in mind that's some surmising on my part, and I have no dog in the fight. The people that use the little EU2000 units for battery charging all tell about how little fuel they use. But there are very few 2 kVA conventionals in the same power class to compare them to. And my testing has shown that once you get into the 3 kVA class where you do have something to compare it to, a conventional can easily beat an inverter unit for efficiency.

I have to edit this because I read 'coot's reply after I posted mine - 'coot makes a good point. If you have your inverter set to accept only low input amps from the generator for battery charging so it matches the capabilities of say a EU2000, there is no convention type generator that is going to match it for fuel consumption. If you have a small off-grid system where it only requires a 2 kVA generator, the inverter type is the only way to go probably. But for larger systems I think a person should explore both possibilities.

I would like to someday test one of the Honda 6500 inverter units against a EM6500SX to see how they fare at full load. But coming up with generators to test is not all that easy because I don't know anybody that has a 6500 inverter unit, and the Honda dealer won't let me use one off the floor
--
Chris

ChrisOlson

Re: Choosing a good generator

unicornio wrote: »

Cris! ... Surely your culture on fuels come from the world of aviation?
am I right? ...;-)

Well, yes. I am a licensed commercial pilot with multi-engine and instrument ratings, and 7 type ratings, qualified as Pilot In Command in heavy turbine-powered fixed wing aircraft.
--
Chris

ChrisOlson

Re: Choosing a good generator

This is some more information on some of the research I did when we selected our new Honda generator.

One of the generators we looked at was a Cummins QD5000 (Quiet Diesel series). This is a link to this generator on Cummins' website:
http://www.cumminsonan.com/cm/products/diesel/compare?gensetId=4&detail=true

The Cummins QD is just like a Honda EU, except on a larger scale and diesel powered. It is an inverter type unit with "eco throttle" so it idles down under lighter loads. It's got a little twin cylinder liquid cooled diesel engine with 479cc displacement. It took me awhile to get some answers on fuel consumption on these things, and it turns out they are absolutely horrible. The same engine in their conventional sets yields much better efficiency in the range that should be expected from a diesel generator.

Now, this is what I was told after spending a couple days on the phone to get an engineer that would answer my questions on it, and I only achieved that after they found out I am a retired engineer that used to work for Cummins. Not many people got these generators because they're a $6,000-$10,000 unit, depending on the size. They are used in RV's, motorhomes, and for Emergency Services applications - they could not give me a single reference to anybody using one for residential or off-grid standby power.
--
Chris

2manytoyz

Re: Choosing a good generator

Here's a great video demonstrating the noise level differences between the various Honda models. The last part of the video does back/back demos.

[video=youtube_share;Uae4l1lNuYc]http://youtu.be/Uae4l1lNuYc[/video]

techntrek

Re: Choosing a good generator

ChrisOlson wrote: »

...I would like to someday test one of the Honda 6500 inverter units against a EM6500SX to see how they fare at full load. But coming up with generators to test is not all that easy because I don't know anybody that has a 6500 inverter unit, and the Honda dealer won't let me use one off the floor
--
Chris

My parents have one, but that would be a long drive for you (to MD).

swmspam

Re: Choosing a good generator

I did some soul-searching and came to the most fundamental question: what purpose do I have for a generator?

I have grid connection and natural gas. My furnace operates on natural gas. I'm in the midwest. Spring tornados, winter ice storms, and long cold weather spells are commonplace. I have ~20kWh of battery storage at 48V. I'm about to configure 6-8kW of split-phase 240VAC inverter into my existing electrical panel. So the generator is for backup. If the generator is connected to the inverter's auxiliary AC input, it can work in conjunction with the inverter in generator support mode. Otherwise, it will operate fixed-power for bulk battery charging.

Since the mission of the generator is backup, let's also assume the natural gas also stops because whatever took down the electrical grid.

Back to the my fundamental needs: (1) electricity and (2) heat. If both grid and gas fail in a winter storm, we are miserably huddled in the basement. If more than a few days, I'd have to evacuate my family to somewhere with heat.

A gasoline generator (my Yamaha EF200iS and maybe a Honda EU6500iS) easily provides electricity. I have enough fuel for a few weeks, which could last much longer if used sparingly. That's in the addition to the 30+ gallons in our two cars.

But that doesn't produce heat, unless we use electric space heaters, which is a terrific waste of the aforementioned gasoline. I don't want to stockpile yet another fuel, such as wood, for a woodburning stove. I could replace my existing stockpile of gasoline for diesel, which is very easy to obtain in farm country.

Therefore, I've narrowed down my solutions sets:

1. Gasoline generator + get a new furnace with a heat pump (use electricity for heating needs)
2. Liquid-cooled gasoline or diesel generator + water pipes + indoors radiator (move the generator's waste heat indoors)
3. Liquid-cooled diesel generator indoors + cogeneration (move everything indoors)

That's nice to have a "mission statement", but there's not exactly a bunch of products at Home Depot to solve these problems. Perhaps (1) is the easiest, but is it realistic?

ChrisOlson

Re: Choosing a good generator

I don't think there's any electrical method of space heating that can be done with a small generator. Wouldn't it better to just install a wood burning fireplace or stove in the basement? We heat our house totally with wood heat. Our furnace is central forced air and the thermostat upstairs controls the draft and forced air blower.

But one of the things you can't do with a wood furnace is shut the fire off. It has to stay burning at least hot enough to keep the catalyst at operating temperature, which means a stack temperature of at least 500 degrees (we have a high efficiency unit with a catalyst afterburner). But when the house is warmed up, even in really cold weather, the thermostat shuts the blower off and closes the draft as far as possible and still maintain the proper burn. The radiant heat off the furnace heats the whole house by heating up the basement and the heat naturally rises thru the floors. Only in really, really cold weather does the forced air blower cycle on and off repeatedly.

Installing a Class A chimney with a wood burning furnace or fireplace is THE most reliable form of backup heat for your home that there is. Wood has been used as a heating fuel since the dawn of modern man. And a simple fireplace or wood stove could save your butt when everybody else is evacuating.

Just my 2 cents.
--
Chris

keyturbocars

Re: Choosing a good generator

Chris,

Sounds like you've lots of good experience with generators. What's your experience or opinion of the Briggs EXL8000 generator (has the Generac OHVI 15HP engine)?

Attachment not found.

I've had one for a long time as a back up to my Onan 6DJE, but I've not used it very much so I don't know how it would hold up long term. My impression is the Generac OHVI engine is better than a typical Briggs engine, but not as good as some of the premium engines like Honda or Robin.

Just curious what your experience is on these generators (and also any of the rest of you guys).

westbranch

Re: Choosing a good generator

and wood, when stored dry, never goes off, lasts in place for years... ready to light. just gathers dust and some dirt.

Blackcherry04

Re: Choosing a good generator

swmspam wrote: »

I did some soul-searching and came to the most fundamental question: what purpose do I have for a generator?

I have grid connection and natural gas. My furnace operates on natural gas. I'm in the midwest. Spring tornados, winter ice storms, and long cold weather spells are commonplace. I have ~20kWh of battery storage at 48V. I'm about to configure 6-8kW of split-phase 240VAC inverter into my existing electrical panel. So the generator is for backup. If the generator is connected to the inverter's auxiliary AC input, it can work in conjunction with the inverter in generator support mode. Otherwise, it will operate fixed-power for bulk battery charging.

Since the mission of the generator is backup, let's also assume the natural gas also stops because whatever took down the electrical grid.

Back to the my fundamental needs: (1) electricity and (2) heat. If both grid and gas fail in a winter storm, we are miserably huddled in the basement. If more than a few days, I'd have to evacuate my family to somewhere with heat.

A gasoline generator (my Yamaha EF200iS and maybe a Honda EU6500iS) easily provides electricity. I have enough fuel for a few weeks, which could last much longer if used sparingly. That's in the addition to the 30+ gallons in our two cars.

But that doesn't produce heat, unless we use electric space heaters, which is a terrific waste of the aforementioned gasoline. I don't want to stockpile yet another fuel, such as wood, for a woodburning stove. I could replace my existing stockpile of gasoline for diesel, which is very easy to obtain in farm country.

Therefore, I've narrowed down my solutions sets:

1. Gasoline generator + get a new furnace with a heat pump (use electricity for heating needs)
2. Liquid-cooled gasoline or diesel generator + water pipes + indoors radiator (move the generator's waste heat indoors)
3. Liquid-cooled diesel generator indoors + cogeneration (move everything indoors)

That's nice to have a "mission statement", but there's not exactly a bunch of products at Home Depot to solve these problems. Perhaps (1) is the easiest, but is it realistic?

I have about the same situation as you do and I ended up counting on the Natural Gas as the best option for long term. I went 10 days during a Ice Storm a few years back and it worked out perfect. I needed about 3 hours of generator run time a day ( PV was out with 2 " of Ice ). I have a no-vent gas fire place in the basement and I was toasty the whole time without a blower with convection. We did very little different other than cooking on the grill and a diesel fuel cooker I made with a coffee can of sand and a grate out of the oven. In my case I could have evacuated the area, but I never felt it was necessary.

One area I did have a problem was the city left to water on, but the sewers were out. They started backing up and my sump pumps had to keep it pumped out. ( had check valves ) but they couldn't hold it all back. I have since had a cut-off valve installed in the sewer line and now I can cut it off completely where it comes from the main line..

keyturbocars

Re: Choosing a good generator

icarus wrote: »

As Chris says,,, you get what you pay for. My limited experince with Generac has not been good. My experience with Honda has been vast, and all good. from EU Series to Ex series, to Honda engines in general. My neighbor has a Yamaha inverter that he has not been happy with. It hunts with low power draw, and he has replaced everything, including the inverter section, the carb, and is now waiting on a Cd ignition modual.

Tony

Tony, Your comment caught my attention. Do you know what model of Yamaha inverter your neighbor has? Were you saying that he had to replace all those components in the process of chasing the one problem of hunting under low power draw, or did all those components fail on his generator?

I bought a Yamaha EF2000is a while back, but reading your comment made me think that I should have gotten a Honda instead!

Ed

ChrisOlson

Re: Choosing a good generator

keyturbocars wrote: »

What's your experience or opinion of the Briggs EXL8000 generator (has the Generac OHVI 15HP engine)?

Unfortunately, I have no experience with that generator. Although the Generac OHVI engines are pretty good, and those I do have experience with.

A few years back Generac and Briggs had an alliance of sorts. In 1998, Generac sold its portable products division to the Beacon group, a private equity firm, who later sold it to Briggs & Stratton. They had a non-compete agreement and Generac re-entered the portable generator market in 2008. So now Briggs has gone back to using their own engines and that generator you got was probably from the era when they were still using the Generac engines, which are built in Whitewater, Wisconsin.
--
Chris

keyturbocars

Re: Choosing a good generator

Thanks for the info, Chris. As long as my Onan 6DJE generator holds up, I won't need to use the EXL8000 much except for portable power around the farm.

icarus

Re: Choosing a good generator

I don't know the model number, but it is a ~2800 watt unit. E issue has been hunting rpm at small loads, he has fallen victim to the diagnose via replacement. Non of the parts so far have proved bad, still waiting for the ignition modual.


Tony

keyturbocars

Re: Choosing a good generator

OK. That's good to know, Tony. I'm hoping my Yamaha EF2000is generator turns out to be reliable.

swmspam

Re: Choosing a good generator

swmspam wrote: »

Therefore, I've narrowed down my solutions sets:

1. Gasoline generator + get a new furnace with a heat pump (use electricity for heating needs)
2. Liquid-cooled gasoline or diesel generator + water pipes + indoors radiator (move the generator's waste heat indoors)
3. Liquid-cooled diesel generator indoors + cogeneration (move everything indoors)

A review of the three options previously posted. I'm sure this will "generate" some opinions. Opine away!

1. Research showed a heat pump is not a viable solution. Under optimal conditions, a heat pump can move 3xBTUs more than the electricity itself. Below freezing, using a heat pump for heating, you're lucky to get 1.5xBTUs for each BTU of electricity. The winter of 2010 we were below -10F for a few weeks. A heat pump would be useless.

2. Piping hot water from an outdoor genset to an indoor heat exchanger in my furnace seems like a lot of work. I'm not excited about that. And I have to build a custom genset with the waterworks and valves to control the flow, depending on time of year.

3. Moving the generator indoors. Use Diesel and install a catalyst directly on the exhaust manifold to minimize CO and vent to outdoors using a fan-assisted inducer. Diesel fuel is also safer than gasoline fumes. People have very vocal negative reactions to indoor generators. Yet those same people have ventless fireplaces? Their very lives depend on sensors and catalysts to prevent CO poisoning! At least an indoor genset would vent the exhaust! If there were an exhaust leak, the compression-ignition of Diesel greatly reduces CO because the combustion propagation, higher combustion temperatures, and larger expansion ratios. Also, Diesel is air-rich (fuel limited), whereas spark-ignition engines are controlled by limiting air (throttled and choked). This genset would also be custom-built, obviously, but with far less waterworks to control the cogeneration. May be difficult to use an indoors generator in the summertime, too.

4. Install a wood-burning furnace (stove) into my existing fireplace and chimney. I'm still working on this solution. Chris, why does your wood furnace have a catalyst? I thought the smoke went up the chimney? I'll keep doing research.

p.s. I occasionally travel to Cummins in Columbus (Indiana) as a consultant for the past three years. I like the engineers there, so I hope to see them more in 2013. Cummins just laid off a bunch of people last month. I think most engineers I work with are still there. I don't know what their situation is, but I presume they are still developing their technology and continuing expansion into China.

BB.

Re: Choosing a good generator

I am not sure you can get enough heat from a smaller liquid cooled genset to really make it worth while. I have seen people a few years ago try lots of schemes to recover heat--But the maintenance (and moving a genset inside, the risk of combustion leaks and lots of noise) and I have not seen any follow ups.

One guy build a solar thermal system that he uses even when there is snow on the ground--Looks very interesting.

Unvented fireplaces are not always legal (I think). The downsides (smell, humidity, using up oxygen in the room, etc.) just do not make sense in the world of modern homes that are much more air tight than the olden days (in my humble opinion).

As far as I know, the catalytic wood burning stove was a response to air pollution rules (completely burn smoke and fuel). There are stoves that meet the EPA requirements without catalysts (when I check this a few years ago). There are some drawbacks to catalytic wood stoves (besides keeping a minimum amount of fire/air for cat. to work, I believe wet/green/wood with lots of sap causes issues too).

-Bill

Cariboocoot

Re: Choosing a good generator

Another emergency heat option: propane furnace from an RV (has to be vented properly of course). May not heat the whole house, but with a bit of planning can keep the pipes and people from freezing and bursting.

inetdog

Re: Choosing a good generator

swmspam wrote: »

A review of the three options previously posted. I'm sure this will "generate" some opinions. Opine away!

1. Research showed a heat pump is not a viable solution. Under optimal conditions, a heat pump can move 3xBTUs more than the electricity itself. Below freezing, using a heat pump for heating, you're lucky to get 1.5xBTUs for each BTU of electricity. The winter of 2010 we were below -10F for a few weeks. A heat pump would be useless.

Unless you are able to use a water-source or ground-source (annoyingly called geothermal!) heat pump. In that case both the cooling and the heating performance increases dramatically, but at the cost of greater complexity and higher installation cost. You won't find it in a mini-split. :-)

ChrisOlson

Re: Choosing a good generator

swmspam wrote: »

Chris, why does your wood furnace have a catalyst? I thought the smoke went up the chimney? I'll keep doing research.

We have an EPA approved high efficiency furnace. It has a catalytic recombustor on it that burns the particulates in the wood smoke. All it emits out the stack is water vapor and carbon dioxide.

The furnace has a normal firebox like any wood furnace. But in the top section of it where the recombustor is there's a bypass damper that you open to get the fire going, and a secondary air inlet for the cat. When the fire is going good you close that bypass damper and send the smoke thru the catalyst. It typically takes 1,200 degrees to burn the particulates in the smoke. The platinum cat "lights" at about 500-600 degrees and burns the particulates. It also gives off tremendous heat. Our furnace is designed to use that heat from the cat by circulating air around the recombustor in the heat jacket.

You get almost double the heat from the same amount of wood that you get from a conventional wood furnace. And zero creosote buildup in the chimney. The controls on the furnace have a stack temperature sensor that keeps the secondary air sufficient so it keeps the cat going (it takes oxygen so the cat can burn the particulates, and maintain the stack temp at 500 degrees).

We really like it. It cut our wood consumption in half. The downside is that the cat has to be removed and cleaned yearly to remove ash from it (I just use a paint brush and air blower), and the cat has to be recycled and replaced about every 5 years or so.

There's a lot of companies that build them now. Just google EPA approved wood stoves on the internet and you can probably find a dealer close to you. Don't buy one over the internet - go to a local dealer that carries replacement cats and the control parts for them - and you won't like the truck freight cost on shipping one from very far away - truck freight on a 80,000 BTU furnace will cost just about as much as the furnace itself these days. Well built wood furnaces are HEAVY - ours weighs close to 1,000 lbs and is made of 1/4" steel. It took four men, one woman, and a refrigerator cart to get it into our basement.
--
Chris

inetdog

Re: Choosing a good generator

ChrisOlson wrote: »

It has a catalytic recombustor on it that burns the particulates in the wood smoke. All it emits out the stack is water vapor and carbon dioxide.
Chris

There has to be either some nitrogen gas or some nitrogen oxides along the way too, but probably not enough for concern. :-)

ChrisOlson

Re: Choosing a good generator

They claim in the propaganda that the combustion temperatures are low enough so there's no NOx. They say just CO and water vapor. I'm sure there's trace gases of other stuff, but it has to be very low. The cat basically runs hot enough to burn the combustible gases that come off wood (wood gas). And there's a LOT of heat in that smoke. We put in a new stainless steel Class A chimney when we put it in and the inside of the chimney looks brand new and shiny yet after two years. Absolutely zero corrosive compounds in the exhaust.

I firmly believe in them after having ours for two winters.

Our furnace is "dual fuel" - it also has the shaker grates in it to burn anthracite coal. Anthracite is the cleanest burning fossil fuel known to man. And the cat works well with anthracite too (burns all the coal gas) and accumulates no ash on it with time. We usually get 1,000 lbs of anthracite and switch to that in really cold weather because it gives off more heat, burns longer, and only have to fire the furnace once a day when it's 20-30 below.

Burning anthracite is more of an art than a science. The first time I tried to burn it I spent four days trying to get it to light. We got stove coal (which is really big chunks as compared to acorn, rice or pea coal). I took a chunk and tried to light it with an oxyacetylene torch and it still wouldn't light or burn. I was convinced anthracite is bogus because it's the final step before eons of time turn it to diamonds. The stuff is almost 90% pure carbon. I finally had to have a guy that knows how to build a coal bed and get it going to come over and show me how to do it.
--
Chris