how big of a generator would one need to power the entire house?

DirtySCREW

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How would you determine how much you need? Obviously, every tv and appliance wouldn't be needed all the time.

But for AC, fridge, stove, lights, fans, a TV, etc...What Should one look at?

Would you need a couple of 7 or 8k watt working in tandem? Like how those Honda's can be hooked together.

DS
 
We're always talking about situational awareness, do you really want to be the center of attention when the power goes out?? Your entire neighborhood is dark, save for a couple of flashlights walking around and then there's YOUR house looking like it's expecting a helicopter landing by Trump & Company... Really??
 
We're always talking about situational awareness, do you really want to be the center of attention when the power goes out?? Your entire neighborhood is dark, save for a couple of flashlights walking around and then there's YOUR house looking like it's expecting a helicopter landing by Trump & Company... Really??
Can't help that others are ill prepared. Living in a neighborhood, there's not a way to be on the low down. I'm not gonna suffer if I don't have to.

DS
 
25KW on average. Thats a big generator. Obviously the size of the house matters. Gas or electric heat, water heater, range, dryer figures in too. If I was building a new house or even moving to my retirement house which I plan to do in the next 5 years, I would get a system with auto transfer switch and get on a preventive maintenance plan with a installer/service vendor, and run the genset monthly under load (automatically as a function of the xfr switch because I can't remember/too lazy to do it manually).
 
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It depends on how many high current appliances that you want to run at the same time.

Assuming a summer or mid winter outage and you want to run a heat pump or air conditioner, most likely 16kw min, with 23-25kw probably a safer bet.

There are online power calculators that will help you determine needs.
 
When I disappear (retire) and put the house in the middle of 300 acres I'll have a whole house generator that will be large enough to not only run the household needs but it will be big enough to power the electric fences that surround said 300 acres.... AND electrify the moat....

If you electrify the moat you will not have any intruders for target practice! Bad move. You'll be bored out of your mind.
 
We had a guy come quote us our options about a week or two ago. We lost power randomly and our well didn't work so my wife got upset and we set up an appointment to see our options and the costs. The guy from Generac came and did a checklist of what we had and wanted to power and said a 22kw unit would cover our guise BUT we would have to do load shedding as a feature to make sure we didn't over load it and draw too much power. That unit was going to run us 10,500 installed with gas connection and permanently mounted. In talking with my wife we decided to change our unit to a 17.5 kw portable unit (not so portable at 325 pounds with wheels) that would cover our whole down stairs which is basically where we live. This would allow us to buy the unit and it we move take it with us instead of leaving it. Our plan is to buy a farm for horses and such in the next 7 to 10 years. For the 17.5 unit it will set us back 7 grand installed and transfer switch and all.
 
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Fill this out...use some common sense when it's done to see if it makes sense. Most houses are in the 15,000-30,000W for minimum essentials. Put an AC unit on there and you might be looking at 30,000-50,000, depending on your house size.
https://www.generatorjoe.net/html/wattageguide.html
 
Something to remember as well is the bigger the unit the more "fuel" it consumes with a load on it. That being said, if it is hooked up to your whole house and you aren't careful you could end up with a huge gas bill.

Buy once, cry once .....that's the motto with generators
 
Like has been mentioned, I would recommend a propane/natural gas unit if you're going for the whole house. You can easily store A LOT of propane and you never have to worry about cycling it out like you would gas or diesel because it doesn't spoil. If you house uses gas you can tap into that and then keep a reserve supply of your own.
 
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I was just looking into this today. As a point of reference, a whole house propane generator (that I was looking at) will consume about 2.5 gallons / hour at half load and about 4 gallons per hour at full load. This means a 1000 gallon tank (fully filled at 800 gallons) would last a roughly a week at near full load and about two weeks st half load, run 24 hours a day. The cost for that much propane would be somewhere around $1,500. While it would be great to have the whole house, you would still want to run it to cool / warm things, lights as needed, and shut it off during an extended outage.
 
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All of the above suggestions are pretty much spot on.
Basically, what do you have..especially anything that heats or cools, and what do you want to work in an outage?
The largest I've ever installed at a home was 80kw. Roughly 340 amps. Powered by a natural gas fed chevy 350 v8. It supplied the 10,000sq. ft. main house, a separate 60kw unit supplied the 4800 sq ft guest house.
And this Lady was still pissed because it wouldn't power the whole damn house at the same time. (the main service was 800 amps). We set her up with load shedding capabilities and told her to just turn on everything, including her 3 laundry rooms she insisted had to all be functional. I still don't think she know how it all works, but she hasn't complained.
 
I looked into a whole house generator that ran on gas but it was going to be like 6,000 installed. I just couldn't spend that much on something I would hopefully not need that much of. Went to northern tool and bought a powerhorse 9000 with electric start which cost about 1,000 if you throw in the power cord. I then had an electrition put in a plug under my fuse box for 600. The thing will pretty much run everything I need. I guess if I turned on everything at once in my house it would overload it but not too many people do that to begin with.
@ Baileyboat- yes it is a beacon for the whole neighborhood to have your lights on and yes people do tend to come over but it is mostly neighbors asking about where you got the generator and how you have it hooked up. But I don't answer the door unarmed ...
 
I've got a PTO powered 20 or 22KW (can't remember right now) nominal/40KW surge generator that I'm going to have wired into the house. Since I've got oil heat I don't need a lot of watts to heat the house. I'm going to have the plug put at the back of the house, rather than in the garage like my Dad's hook up was, so that the tractor is at least hidden from the road. You may be able to hear it running, but you're going to have to look for it.
 
If you electrify the moat you will not have any intruders for target practice! Bad move. You'll be bored out of your mind.
Depends on how you place the moat. Could be ideal. :D

We got so accustomed to outages at one house we developed an outage plan. What got put on aux power and what didn't. Minimal lighting(usually a single floor lamp), microwave, refrigerator(newer units consume a lot less that old ones), cable modem, etc. Did a lot of power label reading. Tried to get maximum efficiency with the least amount of power consumption and assumed I couldn't just go run out and buy more gas. AC was not part of the mix. Fans in the summer, Buddy Heaters in winter.
 
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Heat pumps consume a lot of your load, as does electric hot water heaters. Example: a three ton heat pump could pull 50 amps or more depending on the electric aux strips. Add in the electric water heater and that is going to be most of all the load compared to the rest of the house combined. Most North Carolina homes have heat pumps. But if you plan a strategy of how you use heat, water, and a electric stove you can downsize the generator for temporary power losses and be comfortable.

Make sure you have a qualified electrician isolate the power from normal power. Some guy on a pole working is going to get killed from your unit if done wrong and they will come looking for you.

Get a utilities report for peak winter consumption and have an electrician work from it for your comfort level.
Here would be my plan:

Total heat on main living area.
Refrigerator and freezer
Main living room and kitchen receptacles
Water heater
Well pump
30% of range top, not oven

If you are going to get a unit installed I would not go less than 22 kW for the average NC home of 2200 sqft which is 95 amps. Not everything will be pulling power at the same time. Converting electical from gas will be expensive.
 
The thing about heat pumps is that except for the heat strips the power usage isn't all that high. You should be able to lock those out and still run it. It could still defrost but you might get a little cool blast for a few minutes. Still beats doing without all together.
 
We built our house in 2005 and I made sure to have a whole house generator with an automatic transfer switch wired in. We have a fairly large house and I had a 25kw generator installed and wired into both circuit breaker boxes. It runs the entire house just fine and has paid for itself on numerous occasions over the years. It is powered by a 2.5L Ford and runs on a permanent natural gas connection and we do have it on a quarterly service plan with Clarke Power in Greensboro. We can barely hear it running from inside the house as it purrs along at 1800 rpm. Never have to worry about it. I can set it up to run itself once a week or whatever interval I choose in order to exercise it, but I just go out and turn it on and let it run for about 30 minutes once a week.

It has run for about 5 -6 days during an extended power outage a few years ago and it did a great job. After the power comes back on and it switches over to Duke Energy, the generator will run about 20 minutes under no load to cool off and then it shuts down and waits for the next outage.

Mine is an Olympian 25kw. I believe it was marketed by Caterpillar back then. Here's a pic of one that is the model I have:

img.axd


c14a9646-83b9-4dc3-9c41-91208084c32e.jpg
 
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@Qball out of curiousity, how much gas does it use? My curiosity stems from the idea of the 22kw propane (NG not avail) we're looking at for a build and the specs show it would burn through $1,500 in propane if fully loaded running 24 hours a day for in 5-6 days (~4 gallons per hour) Of course the fuel use is nearly linear with load.

Obviously in an extended outage, just having power, lights, and HVAC would be worth a pretty penny, but it could be a large bill.
 
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@Qball out of curiousity, how much gas does it use? My curiosity stems from the idea of the 22kw propane (NG not avail) we're looking at for a build and the specs show it would burn through $1,500 in propane if fully loaded running 24 hours a day for in 5-6 days (~4 gallons per hour) Of course the fuel use is nearly linear with load.

Obviously in an extended outage, just having power, lights, and HVAC would be worth a pretty penny, but it could be a large bill.


I'm not sure right off. I will find out for you. I do recall our Piedmont NG bill did go up some when we had that extended outage. But it wasn't a huge amount. For example, in the winter our gas bill may run anywhere from $45.00 - $80.00. When we had that outage, the gas bill may have jumped $25.00 - $30.00, just not sure. I'll do a little research and find out when we had that outage. Once I get the month it happened, I can quickly ascertain the effect on our gas bill from Piedmont and I'll let you know.
 
I'm not sure right off. I will find out for you. I do recall our Piedmont NG bill did go up some when we had that extended outage. But it wasn't a huge amount. For example, in the winter our gas bill may run anywhere from $45.00 - $80.00. When we had that outage, the gas bill may have jumped $25.00 - $30.00, just not sure. I'll do a little research and find out when we had that outage. Once I get the month it happened, I can quickly ascertain the effect on our gas bill from Piedmont and I'll let you know.
Thanks, that would be great information. From what I've read, the house would normally use about 100 gallons in a year for cooking and hot water. The idea of having outrageous bills for a generator makes me uneasy. It's hard to translate a spec sheet into real dollars sometimes.
 
Thanks, that would be great information. From what I've read, the house would normally use about 100 gallons in a year for cooking and hot water. The idea of having outrageous bills for a generator makes me uneasy. It's hard to translate a spec sheet into real dollars sometimes.

No problem. I briefly looked at power outage history today and did find a 6 day ice storm outage that occurred back in Dec. 2005. It was in the Piedmont so that could be the one I was thinking of. But I was at my office and my personal bank records are archived on my laptop here at the house. But it shouldn't be too hard to get a gas bill correlated to an outage. I'll keep you posted.
 
Sad to admit but I've had dozens of generators installed on various properties in my portfolios and never paid much attention except to check off another item from my list. Best as I recall the majority have been NG with a few diesels thrown here and there if NG wasn't available in the area. Never done a Propane though.
BRIGHT IDEA!!! How about I remove my head from my butt and PAY BETTER ATTENTION......
 
We built our house in 2005 and I made sure to have a whole house generator with an automatic transfer switch wired in. We have a fairly large house and I had a 25kw generator installed and wired into both circuit breaker boxes. It runs the entire house just fine and has paid for itself on numerous occasions over the years. It is powered by a 2.5L Ford and runs on a permanent natural gas connection and we do have it on a quarterly service plan with Clarke Power in Greensboro. We can barely hear it running from inside the house as it purrs along at 1800 rpm. Never have to worry about it. I can set it up to run itself once a week or whatever interval I choose in order to exercise it, but I just go out and turn it on and let it run for about 30 minutes once a week.

It has run for about 5 -6 days during an extended power outage a few years ago and it did a great job. After the power comes back on and it switches over to Duke Energy, the generator will run about 20 minutes under no load to cool off and then it shuts down and waits for the next outage.

Mine is an Olympian 25kw. I believe it was marketed by Caterpillar back then. Here's a pic of one that is the model I have:

img.axd


c14a9646-83b9-4dc3-9c41-91208084c32e.jpg

I had one of these installed for one of the owners of a company I used to work for. It was a 100KW diesel Olympian. Had to crane it in to the back of his property from the end of his paved driveway. Then he had another contractor build a "picnic" shelter over it that was structurally pretty beefy thinking it would keep tree limbs and trees off of it in an ice storm. The other company owner had a 300KW Cat diesel genny installed at his house. The 100KW unit had a 600amp xfr switch. I can't remember what size service or switch the 300KW unit had. Both these guys had enough money to build nuclear power plants in their back yards.
 
Even with an unlimited budget you have to run these things under load monthly (called exercising) and you have to get them PM'd annually and if diesel keep the tank topped off monthly or they are just expensive boat anchors.
 
Be sure and look at the gallons per hour figures of the big generators. Then go look at the giant propane tanks.

WTH am I going to put a 500 gallon tank was a concern for me.
 
Even with an unlimited budget you have to run these things under load monthly (called exercising) and you have to get them PM'd annually and if diesel keep the tank topped off monthly or they are just expensive boat anchors.

Yep....
You don't just plant one and expect it to live. I'm eventually going to have a 30kw or bigger diesel genny sitting on a 100 gallon pedestal tank. In a pinch, they can be readily converted to run on other fuels....propane or LP...not so much


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I had one of these installed for one of the owners of a company I used to work for. It was a 100KW diesel Olympian. Had to crane it in to the back of his property from the end of his paved driveway

We had to set this little one that I have down back behind my house with a crane. It's amazing how heavy they are.
 
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