Back-up home generators

[Flivver250]

I have always used portable Honda generators for back up power for outages. I still have a couple, but mama doesn't have the stamina to wheel one over and hook it up in the middle of the night anymore. Thinking about wiring in an automatic whole house generator in the 20 KW range which should handle everything we would throw at it. I see Generac has some fair pricing on liquid and air cooled models that run on LR or natural gas. Anyone have experience with this brand or recommendations for another brand? I'd have to install a 250 gallon or larger LP tank and would prefer a diesel unit, but do not know the pros and cons. I'd think diesel would be cheaper and more fuel efficient. Searching for ideas and figure some of you lads have been down this road.

 

[Stuart in MN]

You may want to search in the electrical forum, I believe whole house generators have been discussed there a number of times. Generac is a decent brand for residential use, Cummins/Onan is another. You can get LP, natural gas or diesel. Given the choice for ease of use I'd prefer natural gas, but if you don't have that available go with LP or diesel. You'll have to evaluate the cost of operation for each type (you should be able to get fuel usage specs from the generator manufacturers), as well as which fuel is going to be easier for you to replenish.

 

[madwi]

We have a Generac whole house and it is amazing. I believe it comes on after 10 seconds of power going out. It runs on natural gas. Sure is a nice feeling not having to worry about freezers thawing and having internet up and running makes the time go by faster than sitting in the dark. It starts up once a week and runs for about half an hour on its own. Battery has lasted for a few years even though it says it is low.

 

[theoldwizard1]

I would be concerned about storing diesel fuel for long periods of time. If you had a 200 gallon tank, what is that fuel going to be like 5 years, 10 years down the road ?

If you have natural gas use it. If not, LP would be the way to go.

 

[rlitman]

I would be concerned about storing diesel fuel for long periods of time. If you had a 200 gallon tank, what is that fuel going to be like 5 years, 10 years down the road ?

If you have natural gas use it. If not, LP would be the way to go.

There's something to this. We store quite a lot of diesel at work for generators, and need to regularly test the fuel. LP never goes bad in storage.

 

[Flivver250]

Madwi, I see I was your first post. I took your GJ virginity? Thanks for the endorsement of Generac. Always nice to hear from happy customers. LP makes sense for long term storage. As we just moved and did not bring our diesel tractor, I don't currently have any diesel powered equipment to swap the fuel out with so the fuel going sour would be a concern. Couple that with I only go to America once a year, low maintenance for the win. LP it is.

 

[Tim Kennedy]

Flivver25o: Try www.hardydiesel.com -- nice units, good info, decent prices. Did research myself awhile back for my own needs & thought their sight was pretty good.

 

[madwi]

Madwi, I see I was your first post. I took your GJ virginity? Thanks for the endorsement of Generac. Always nice to hear from happy customers. LP makes sense for long term storage. As we just moved and did not bring our diesel tractor, I don't currently have any diesel powered equipment to swap the fuel out with so the fuel going sour would be a concern. Couple that with I only go to America once a year, low maintenance for the win. LP it is.

You sure did

 

[Stuart in MN]

Long term storage of diesel fuel is a concern, but also remember that no matter what fuel is used the generator should be exercised on a regular basis - you want to make sure it's in good condition and ready to run when you need it. As a result, you should be using up that diesel and replenishing it as you go.

 

[Flivver250]

Tim thanks for the site, interesting reading. My search is going to be fun.

 

[mburrus]

what size house and what are the major loads? 10-15 should be suitable. liquid cooled is preferred as well as 1800rpm running speed. as this will be for backup only, i suggest lpg or natural gas, not diesel, due to storage and geling issues.

 

[astrohip]

I have standby generators at two homes, so I can pass on some experience.

[Aside: Typically when you talk about a portable gen, you call it a backup generator. When you have a permanently wired gen that can handle all or most of a house, it's called a standby generator.]

Fuel: Nat gas is always your best choice if it's available. Even during storms and disasters, nat gas tends to be available. We have NG on one unit (city home).

If not, propane is next best. It can be stored long-term, very reliable, easy to get refilled. Heck, in an emerg, you can hook up those portable BBQ bottles (not recommended, but doable). We have propane on our country home. 1,000 gallon buried tank.

Diesel is last. They make for great generators, but getting refilled, and long-term storage, can be issues.

Brand: Generac owns the homeowner market. They make decent and competitively priced units. Their air cooled are very reliable, but can be noisy. The liquid cooled are also good, and quieter. But cost much more.

I have a Generac 18K, and a 20K. One for 7 years, the other 10. No problems with either. They self test once a week for a few minutes.

I have them serviced once a year--oil change, filters, check the battery, etc. I've been told by a tech they can run about ten days straight before they would need service, primarily oil change.

They kick in about 10-15 seconds after power fails.

 

[Flivver250]

The house has a heavier load with AC and a pool pump. Other than that, typical load for a 1-2 person home. Refrigerator, stove, lights, etc.

 

[sixty4]

I looked into the 20kw generac as well. I am on LP, my concern was that my heating system is on LP as well. Talking to the propane company he tells me they have what's called a tank alert that sends a signal when tank gets to a certain percent? I was set to have another tank buried until I heard about the tank alert system. My worry is if for long extended times using what I have left in the tank and can they get here in a reasonable time should I run out. These generacs go through a good amount of fuel depending on load as I have been reading.

 

[Cypherian]

I have a generac GP6500E gasoline for my purposes is it is fine my only issue with it has been the built in battery tender it tended not to work right removed it and put a standard battery tender on it. Something to consider on the LP ones here in the Mid Atlantic one of the ones on my work property is LP they had to put a dog house over the regulator to keep it from freezing up . Mind you this generator and tank are out in the open and we get very high winds and freezing moisture here alot. My dad has a generac lp in Maine and so far it has not needed the regulator heater but he had to have the motor replaced under warranty with in a year. Mind you the motor really did not go bad it was the idle control but since it was so new generac wanted the whole motor and control set back to examine. Good company service but if the unit had been needed well.. All the great company service in the world won't keep you warm in the winter. Check your service companies in your area see what they sell and service etc.

Cypher

 

[retfr8flyr]

I have had Generac standby generators, powered by my propane system, on my house for 15 years. The first one lasted 10 years before it gave up and that was through several long power outages. I now have a 20KW unit that is a huge improvement over my original unit. I have it on a service contract and they come out once a year to give it a complete check and oil change. I highly recommend the Generac units for residential use.

 

[nick2010tundra]

I have a Generac Standby as well and am very happy with it, I run off propane and have had zero issues.

 

[theoldwizard1]

One of the things I do NOT like about "whole home" generators, is they make you size them for max load. That is fine for some little old lady who has no knowledge of electricity. Anyone with more than half a brain know you almost never pull that much current.

If you live in the North, you need enough power to run your furnace, all of your refrigerators/freezer, sump pump and a microwave. We could argue about an electric stove, but if you are going to put in a propane tank for the generator, why not use propane for the stove, water heater and dryer ? If your not on city water, add in a well pump.

If you live in the South, you need to run your A/C, all of your refrigerators/freezer, sump pump and a microwave.

In either case, those are typically less than 20kW maybe less than 10kW.

 

[Stuart in MN]

One of the things I do NOT like about "whole home" generators, is they make you size them for max load. That is fine for some little old lady who has no knowledge of electricity. Anyone with more than half a brain know you almost never pull that much current.

Move the essential circuits to a subpanel, and connect that subpanel to your transfer switch. That way the generator only has to be sized to handle those essential circuits.

 

[atty5420]

One of the things I do NOT like about "whole home" generators, is they make you size them for max load. That is fine for some little old lady who has no knowledge of electricity. Anyone with more than half a brain know you almost never pull that much current.

If you live in the North, you need enough power to run your furnace, all of your refrigerators/freezer, sump pump and a microwave. We could argue about an electric stove, but if you are going to put in a propane tank for the generator, why not use propane for the stove, water heater and dryer ? If your not on city water, add in a well pump.

If you live in the South, you need to run your A/C, all of your refrigerators/freezer, sump pump and a microwave.

In either case, those are typically less than 20kW maybe less than 10kW.

I concur wholeheartedly. Do the math. At .15 to .20 per kwh......if your normal house load was 20KW, you'd be racking up $3 to $4 per hour, or about $75 to $100 per day. Most households, even with A/C running are well under 10KW. After all, it is supposed to be an "emergency" generator to run the essentials during the outage, not every device in the house all at once. That 15 lb. turkey can wait 'til the power comes on.

 

[ddawg16]

If you are running your AC on a generator, then I guess you're not into 'roughing it'.

I concur on the LP route. Safer and stores longer.

But, I'd also look into other technologies as well....such as solar cells and batteries. At the rate the battery technology is advancing (think Musk), a viable battery for the home is not far away.

Having more than one energy source will go a long ways to reliability.

 

[astrohip]

Roughing it? A week without power in the summer after a hurricane, when the temps get into the triple digits? Sure, you can do it, but why? I'll let you rough it, I'll stay cool.

As far as sizing, I somewhat agree you don't need to size for max max, but be careful how close you cut it. The price diff between the air-cooled units is fairly small, compared to the overall cost (install, plumber & elec, etc). And many devices require more juice when they turn on. Just do a smart analysis of how much you need, how much you can safely not use during an outage, cost of the generators by load, etc. Then decide.

A typical house under 3000 sqft, with one or two a/c units, and a mix of gas & electric appliances can be driven easily by the very common 20kW Generac. However, if you have an all electric house, you may be pushing it.

I have one unit that can mostly handle the entire house, and another that is slightly undersized. To right-size the undersized one would have driven the cost from 8K to 12-14K. So I have to be careful which a/c units are on, or how many major juice-sucking devices get turned on during an outage.

 

[NUTTSGT]

We have a diesel stand by generator at the fire dept. It runs every other Monday morning and has a built in block heater. The latter has been the only issue we have had with it, granted it's a large commercial unit that runs the entire station.

I've suggested that my parents get a back up generator for their home as they live in the woods in a rural setting and have had some outages during the winter. They heat with LP and have a vent-free heater in the basement for added heat. If I was in their shoes, I'd get a LP generator as the LP tank and electric service entrance are on the same side of the house.

Since we use fuel oil in our home, I would get a diesel generator. I could rotate the old diesel into the fuel oil tank after a few months.

Personally, I would base my choice on the type of fuel that is readily available at the point of usage. Got NG at home, by a natty gas unit, use LP for your heat, tie into the line running to the home and have a large "endless" tank at your disposal.

 

[bczygan]

Maintain whatever you get.

We just had a one day outage and didn't........!

 

[Gary_montague]

we had a 11K unit installed two years ago. It has worked flawlessly so far. We do have the company autorized service plan and the unit gets checked every six months. I have a portable tht needs to be re-energized due to non-use. If you were to use one every few months or used it all the time to build things. you should probably skip the expense and stick with a portable. For us this is the way to go. we are 10 to 15 miles from the nearest small town. the transfer switch works so well that you can miss the fact that it even was used. So far i am a believer, but we are too old to want to go through some of the outages like we used to do. They are no longer fun!

 

[bob15]

Diesel fuel will have an allege start growing in it during storage if not treated. Diesels units are also much more expensive.

For LP and a 20kW generator, a 500 gallon tank should be considered minimum in size. I would question if you really need that big of a unit. Take the calculators that are on the net, they figure you to have every electrical appliance on at the same time. Do you really think you will use the toaster, coffee pot, iron, microwave, clothes dryer and a hair dryer all at the same time? Probably not.....

Myself, I have a 12kW Gillette generator. Have yet to have any issue with it. I went with the smaller unit due to the fact I won't run everything at once and don't need the wasted fuel consumption of the 20kW unit. With the 12kW, I can run: a fridge, a stand-alone freezer, sump pump, well pump and lights for starters.

My generator was under 6k a couple years ago, including an Eaton automatic transfer switch (200 amp rating). I installed the generator myself, including gas and electrical. I would definitely recommend the US made Gillette. their customer service is top notch as well.

looks like this:

https://www.gillettegenerators.com/products/1/SPS-120

 

[reader2580]

If you are running your AC on a generator, then I guess you're not into 'roughing it'.

My previous house had a Kohler 8,500 watt standby generator. It turned out the unit was large enough to power the central A/C even though that was not the intent when I bought the generator. I moved the A/C from the main panel over to the generator sub panel during a three day outage one summer.

I lived in the house for 12 years and I had only one major outage. I figured the generator cost me $75 for every hour of power outage in that 12 years.

I also like that Sentry-Pro generator. They had a deal last Fall on their website where the 12KW residential was around $3100 including shipping. I should do something for my current house as I have no well without power.

 

[56FordGuy]

The house I just bought has a 15,000 watt propane Generac generator hooked up.

So far, I've found it has no oil in the engine and the battery had exploded at some point.

Wonder what I'll find when I put a new battery in it...

 

[bob15]

The house I just bought has a 15,000 watt propane Generac generator hooked up.

So far, I've found it has no oil in the engine and the battery had exploded at some point.

Wonder what I'll find when I put a new battery in it...

Check the air filter and even the exhaust)....might be a mouse nest in there

 

[56FordGuy]

Check the air filter and even the exhaust)....might be a mouse nest in there

Already did. Both were mouse free, but curious to see if the starter is burnt up or the engine seized. Even blown, the battery had 12 volts at rest which kept the auto start timer running, so once a week the generator tried to start and test itself. The battery dropped to 4 volts under a load so it couldn't turn over, but the programmed test schedule would try it.

 

[Mustang51js]

Since your not around much I would look into a 12-14kw general with the breakers built into transfer switch. This way you can put a few things on it and won't use up as much lp. Honestly do you really need the pool running when you have a power outage. Is there someone who watches the home when your not around. Lp can go quick if you have a big load and it's running for a few days

 

[Mustang51js]

The house I just bought has a 15,000 watt propane Generac generator hooked up.

So far, I've found it has no oil in the engine and the battery had exploded at some point.

Wonder what I'll find when I put a new battery in it...

Pretty much means the old owners didn't do any service to it. I had one lady call me after two years saying her gen won't start. Went over and the low oil safety was on,she never checked or or had anyone check it

 

[theoldwizard1]

Personally, I would base my choice on the type of fuel that is readily available at the point of usage.

A completely logical thing to do.

 

[mburrus]

i would say 12-15 depending on your ac size. pool pump isnt a necessary run, but you can alternate it with the ac so you dont have both loads on the generator. we did a hurricane in 2005 with a 3 ton ac and a 10kw generator and it was loaded to about 40-50%. we had solar for hot water and a gas stove... size accordingly, but theres no need to over do
it.

 

[Flivver250]

If I was home I'd stick with my portable 6.5 kw Honda and my extra Honda 5kw. Because I am not, I'd like to plan for the worst. Can't count on my wife to competently hook it up, start it and manage the load. 30 years of marriage have taught me well where and when she will drop the ball. I do have a 10kw solar system that dumps 100% into the grid, not the house. The revenue from that power generation is better business than a battery system at this point in time. It eliminates almost all of my electric bill but is not a back up system.

 

[HoosierBuddy]

I think you guys have got this covered 12 ways from Sunday, but I wanted to add for the "natural gas" crowd (a great choice, I would agree) that you need to look at the generator's gas requirements and verify you can provide adequate volume and pressure through your current meter set OR check with your gas co. to verify that they can upgrade your meter and/or pressure regulator to meet the generator's requirements.

At or near sea level the vast majority of gas services are going to be set up to provide 7-inches water column pressure (0.25 PSI) at the meter. The most common size of gas meter I see is rated at 275,000 BTU's per hour. However, there are tons of variations out there, with many new homes being built with 2 PSI meter sets and some large homes having much larger gas meters than have typically been used in the past.

My company actually had to install a 1.5 Rotary meter on pounds at a RESIDENCE a few years back (actually if I told you the owner, 99% of you have heard of him). That meter on pounds can deliver roughly 4,000,000 BTU/s hour, and the biggest load was the generator.

Phil

 

[hardalada]

Don't forget that the generator needs to be able to easily start the largest load it would normally carry , and that this starting load can be three times the rated wattage of the unit when it is running , e.g. an A/C unit that nominally runs at 3 kw will need a generator of up to 9 kw to start without stressing the generator and browning out the other appliances that are connected already.......don't go undersized..it is false economy after you have to pay to replace voltage sensitive electronics......

 

[muddy tires]

We were going to go with the natural gas fully automatic setup until we found out how much it was going to cost to upgrade our gas line over 200 feet to the road. Took the budget to a whole new level.

We decided on the portable route.

 

[LS6 Tommy]

In order of preference: Onan, Kohler, Generac. Watercooled, aircooled. 1800, 3600 rpm. Natural gas, LP, Diesel.

Tommy

 

[theoldwizard1]

In order of preference: Onan, Kohler, Generac. ...

Onan is not the Onan of "old". They were bought out by Cummins in 1992. Cummins does market under that brand name.