Standby Generator

tank a holic

tank a holic

Active Member
I have free natural gas on my land
I was looking into standby generators
for about two thousand I can get 8/7 kw with auto disconnect, this unit is labeled as a "critical circut generator"
there are 20kw "whole house generators" for about four thousand
my question is how many kilowatts does it really take to run the average home?

It seems like to me seven to ten kilowatts ought to run my house
I have county water so theres no pump to run
I have 2016 sqft upstairs and about 1300 downstairs
 
scsinet

scsinet

Active Member
It all depends on how much you want to run. If, for example, you can forego and electric range, dryer, and air conditioning, then you probably don't need all that much.
But if you want to light up the home as if the power was on, then you you need to size accordingly. If you have free natural gas that you can tap (make sure it's not town gas or coal gas, as these may well damage the engine), then you might as well go bigger. When sizing a generator, you usually have to balance delivered power with economy of operation, but that's not really a problem for you.
You need to figure out your electrical service size. Most homes have 200 amp nowadays - at least most homes your size - so multiply 200 (amps) * 230 (volts) to get the wattage delivered = 46,000w or 46kw.
In practical application, even with all of your high power appliances running, your house probably never draws that much. In the latter case, 20kw *might* do it, but that's only 86 amps, which, depending on what appliances you have, could fall short.
 
tank a holic

tank a holic

Active Member
Thanks... I figured if someone answered this thread you would be one of them lol
that makes sense but I never knew the relationship between watts / volts and amps
I'll look a little more into it but it sounds like at least get the 20
(yes it is a 200 amp service and natural gas)
 
bionicarm

bionicarm

Active Member
Most of the older Central A/C and heating units required 40A for the initial startup. When running normal, I think it drops down to 20 - 25. I have a buddy that has a two-story, 3200 sq. ft. that bought one of these puppies to run his entire house. This doesn't include the Automatic Transfer Switch, which costs another $1000 or more.
http://www.northerntool.com/webapp/w...8929_200338929
 
bionicarm

bionicarm

Active Member
Take a look at your last electric bill. It may show some statistics of usage on it. You may want to contact your local utility company. They may have average current draws that come out of your house to the meter. I've never tried it, but could you hang an Amp Meter over the power line that goes into your power meter and see what current load is on that line when you have everything turned on in the house that you'd have on during a power failure?
 
scsinet

scsinet

Active Member
I doubt the electric company is going to be able to tell you your average current draw, unless you have a "smart meter." Most of us have the old school meters that just keep track of the total amount. Worth a call though, not saying anything is wrong with trying.
Bionic's comment did make me think of something...
If you are really serious about looking into a full generator solution, you might want to put a device on your panel that will actually keep track of your power usage for you.
Google "The Energy Detective." For about $200, you can get a wireless device that clamps onto the main cables coming into your panel and keeps track of the power going through them. The statistics are uploaded to Google, which will allow you to pull up graphs and average trends. It might be a good investment to get something like this and run it for a few months to actually see what you use, and allow you to size a generator accordingly.
As a side benefit, you can probably pay for this device in no time by keeping an eye on your consumption and learning how to do things to drive your daily averages down. I have one of these deals on my xmas list, hope I get it.
One thing to keep in mind is that those standby generator packages that HD and Lowe's sell that come with the transfer switch are only designed to handle a few circuits. If you want to handle the whole house, you need a large transfer switch that actually goes between the utility and your breaker panel, and switches the entire house over. This is going to be more expensive, and would be a professional installation job for 95% of homeowners.
 
bionicarm

bionicarm

Active Member
Originally Posted by SCSInet
http:///forum/post/3190995
I doubt the electric company is going to be able to tell you your average current draw, unless you have a "smart meter." Most of us have the old school meters that just keep track of the total amount. Worth a call though, not saying anything is wrong with trying.
Bionic's comment did make me think of something...
If you are really serious about looking into a full generator solution, you might want to put a device on your panel that will actually keep track of your power usage for you.
Google "The Energy Detective." For about $200, you can get a wireless device that clamps onto the main cables coming into your panel and keeps track of the power going through them. The statistics are uploaded to Google, which will allow you to pull up graphs and average trends. It might be a good investment to get something like this and run it for a few months to actually see what you use, and allow you to size a generator accordingly.
As a side benefit, you can probably pay for this device in no time by keeping an eye on your consumption and learning how to do things to drive your daily averages down. I have one of these deals on my xmas list, hope I get it.
One thing to keep in mind is that those standby generator packages that HD and Lowe's sell that come with the transfer switch are only designed to handle a few circuits. If you want to handle the whole house, you need a large transfer switch that actually goes between the utility and your breaker panel, and switches the entire house over. This is going to be more expensive, and would be a professional installation job for 95% of homeowners.
My buddy told me the transfer switch he needed for his generator was going to cost close to $2000 plus installation. All the transfer switch does is switch from utility power to generator power seamlessly when power is lost. It's not a requirement for hooking a generator to your home. He told me for the $2000+ to get the thing, he could manage to walk outside during a power failure and manually crank up the generator and 'flip the switch'.

You missed out on a deal with me tank. My brother's company is moving to a new location, and they have a 150KW diesel generator, including a transfer switch, that they sold to a company that handles frozen tissues for $8500. I actually thought about buying it, but I think my Homeowner Association would have sued me when this thing cranked up during a power failure.
 
scsinet

scsinet

Active Member
Originally Posted by bionicarm
http:///forum/post/3191366
My buddy told me the transfer switch he needed for his generator was going to cost close to $2000 plus installation. All the transfer switch does is switch from utility power to generator power seamlessly when power is lost. It's not a requirement for hooking a generator to your home. He told me for the $2000+ to get the thing, he could manage to walk outside during a power failure and manually crank up the generator and 'flip the switch'.

I've considered the same thing. My own issue is the protection of my tanks, I'd prefer something automated in case it happens when I'm not home.

As a cheaper alternative to an ATS, you can get kits with a manual switch and a heavy duty outdoor male recepacle to make it super easy to hook up a portable generator, just like you were saying. I don't know of any manual method for handling a 200a service though...
The flip side is that there are good deals to be had on this sort of stuff these days.... with the economy in the tank, lots of companies are going out of business so there is a lot of this sort of stuff in auctions. Industrial auctions almost always have stuff around.
Google "GNC Power." They sell all kinds of used stuff, I bought a 250kw diesel genset from them a few years ago for 20K - helluva bargain. They mostly deal in large scale equipment, but when I bought the generator, I flew to Texas to take a look at it before I bought it, and they had TONS of stuff sitting around their warehouses that were not on the web site. A phone call to them might yield a good deal - especially since the smaller stuff they may just want to get rid of.
 
scsinet

scsinet

Active Member
Originally Posted by tank a holic
http:///forum/post/3191008
there's a well on my property, I sell some gas and use enough to run my house (furnace, hot water heater ect.)
If I had this arrangement, I'd probably buy a huge generator rated for prime power (constant run) and just get my electricity from that... maybe even sell power to the utility.
 
tank a holic

tank a holic

Active Member
that is an option i've thought about, however....
2 things
1. I need to check the pressure at my well head and calculate weather it would handle the load of a generator running constantly knowing that generators consume alot of gas
2.working at a power plant I know that megawatts are the measurment at witch electricity is sold on the open market, mega watts = 1000 kilowatts or 1,000,000 watts. Now... the time that utilities really make money are on really hot summer days and really cold winter days
consider this, on your average day megawatts sell at $30 per hour now at that rate I could sell the gas for more than I can sell my small ammount of electricity... but on peak days (really hot or cold) megawatts can sell for as much as $700 per hour on these days I could make money but understand that there may be 5 days like this a year and they only bring that price for about 3 hours on those days therefore deeming it uneconomical from my standpoint.
as for the auto transfer switch, the models I looked at, the 8/7kw generator was 1995.95 its self or 2295.95 with the switch so only $200 for the switch w/o installation. But im not sure if that was a big enough switch to run my whole house or just the "critical circuts"
 
scsinet

scsinet

Active Member
Yeah and maintenance might be an issue too... I wonder how many hours a traditional ICE configured to run on natural gas would run before needing major overhaul work.... a turbine would be the way to go but those are wicked expensive. Plus, you've got to put the equipment in place to synchronize the rotor of your generator with the waveform of the ultility so you can do a grid tie...
They do this a lot in the solar panel market using grid tie inverters, but it's a whole lot easier to do the synchronization electronically like inverters do than mechanically like you'd have to do with a generator. Plus, solar panels have no moving parts, so they are basically maintenance free.
I've seen dairy farms set up with banks of generators that run off the methane from the manure the cattle produce, but the farms are themselves huge power consumers so it might be more economical in that case.
Dunno... regardless, if a megawatt genset came on the market for a good price, it might make for an interesting project. Then again, a "good deal" on a 1MW+ genset would probably be a couple hundred thousand. I don't know about anyone here, but I don't have 200 grand, spent it on my nano tank.
 
cranberry

cranberry

Active Member
Excellent thread. We are moving 2010 and want a generator that will auto kick-in if the power goes out. The only things I really care about to be on be auto'd on would be tank equipment (and maybe a freaking alarm clock) with the option to plug other things in if its an extended outage (like post huge earthquake). We are going to have a coldwater biotope.... the power can't be out on that one for any length of time.
 
tank a holic

tank a holic

Active Member
Originally Posted by SCSInet
http:///forum/post/3191533
Yeah and maintenance might be an issue too... I wonder how many hours a traditional ICE configured to run on natural gas would run before needing major overhaul work.... a turbine would be the way to go but those are wicked expensive. Plus, you've got to put the equipment in place to synchronize the rotor of your generator with the waveform of the ultility so you can do a grid tie...
3600 rpm here
Dunno... regardless, if a megawatt genset came on the market for a good price, it might make for an interesting project. Then again, a "good deal" on a 1MW+ genset would probably be a couple hundred thousand. I don't know about anyone here, but I don't have 200 grand, spent it on my nano tank.

the plant I work at actually has 2 125MW turbine generators maybe I can get one lol
probubly only a couple million

in all seriousness if you had the generating capacity it would pay to run your generator and sell at the right time..... if you know when it is
 
t316

t316

Active Member
Damn....Too much technical talk here. I'm just impressed by the concept of having your own gas well on site. What the heck does that look like? All I can picture is A) a well like a water well with the cement cover, or B) a Big Freakin' texas oil tripod with a hammer going up and down....
 
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