# Small Backup Generator



## lucyp (Jan 30, 2011)

Having been snow-trapped this week, I have been wondering about backup generator options. I would need just enough to keep the fan blowing on the propane furnace, a light on occasion, modem and charge a laptop on occasion. Obviously, I could go with a standby generator that runs on propane, and then I wouldn't have to worry about running out of fuel so quickly. But I would prefer (a) to spend less money, since I wouldn't be trying to run my house as I usually do and (b) to do something not requiring fuel.

Anyone have any thoughts on a small solar system that could do the above or even a small windmill? I have plenty of wind on my property most of the time.

Thanks!


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## PD-Riverman (May 24, 2007)

Why not put together a battery bank, keeping it charged while you got power, then if the power goes off you can run off the batteries with a inverter. If you want to add a solar panel later you can. Get all this hooked up and test it out to see how long it will last with the power off, BEFORE the power does go off. Then if you need it to last longer---ADD. Good Luck





lucyp said:


> Having been snow-trapped this week, I have been wondering about backup generator options. I would need just enough to keep the fan blowing on the propane furnace, a light on occasion, modem and charge a laptop on occasion. Obviously, I could go with a standby generator that runs on propane, and then I wouldn't have to worry about running out of fuel so quickly. But I would prefer (a) to spend less money, since I wouldn't be trying to run my house as I usually do and (b) to do something not requiring fuel.
> 
> Anyone have any thoughts on a small solar system that could do the above or even a small windmill? I have plenty of wind on my property most of the time.
> 
> Thanks!


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## lucyp (Jan 30, 2011)

Genius! Thanks much.


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## Tarheel (Jan 24, 2010)

I think the first thing you need to know is the total watts of all that you want to do and then maybe increase it by 10%. I will leave the solar to the experts on here. If all you want to do is run a blower and a light (no refrigeration) then my thinking would be a small Honda generator. This would be one that you can start easily each month and not take a lot of fuel. As I said in the beginning you need a little more info of total watts of each appliance that you want to run.

This other guys will follow up with your solar options.

I bow to the Solar Guys now- Have at Jim-mi, TnAndy


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## lucyp (Jan 30, 2011)

Tarheel, that is what I would have said I should do 4 days ago. Problem is that I live so far out that we could not leave our property for gas, and the county couldn't get to our road to doze it until today. Thus, knowing how much gas to keep on hand would be a problem making renewable that much more important in this situation. If the power had gone out this week, we would have been in serious trouble. (Our furnace actually did go out, but my husband was able to fix it.)


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## Tarheel (Jan 24, 2010)

Gas is not that hard to store with the right additives. You can store for several years now with (PRI-G) and a few others. You mention propane, and you can get small generators to run on it also. If you already have propane in larger quantities, that's the way to go with a generator. I store both- gasoline and propane for extended outages. By no means am I trying to talk you out of solar. These guys will chime in later, but has the sun been out enough in the last 4 days to charge batteries ? You might would still have to have a generator or a mighty large battery bank.

Food for thought.


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## Windy in Kansas (Jun 16, 2002)

The furnace thermostat may also need to be electrically provided for continually to keep the furnace going, so without a battery bank and inverter a generator might have to run continually to provide it. 

I agree with PD-Riverman with what he suggests. If solar or wind can't keep up with usage one could always use a vehicle alternator powered by a gasoline engine. Yes, a generator but it would charge the batteries rather than providing direct power. You might possibly already have a lawn mower engine that would work so there wouldn't be too much additional cost. Even a salvage yard generator might work to lessen the expense further.


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## TnAndy (Sep 15, 2005)

Nice thing too about propane based generators is they usually don't have a lot of problem from sitting around unused for a while, whereas a gas powered one will gum up the carb if you let it sit for 6months/year unused. Then you have to spend an hour or two to get it running again.

But, yes, a battery bank is the way to go, even IF you buy a generator, so you don't have to run it 24/7.....just enough to recharge the batteries.

Then it's not too much of a leap to go wind/solar.


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## Darren (May 10, 2002)

Here's a slightly different idea if you're considering running off a battery pack. Why not use an uninterruptible power supply (UPS) wired into the circuit? Most folks will think about those small things some of the office supply places sell. Clary has been making UPS units for decades. They don't sell something for consumer use but that doesn't mean you can't buy one. A Clary uses 120V or other input power to charge the internal batteries. Then it takes the battery power and regenerates say 120V power with a perfect sine wave for output. That means it's great for running sensitive electronics.

Here's one that is currently up for bids on ebay. They make larger and smaller units. This one produces 25 amps @ 120V output. I see the units on eBay from time to time, but they usually don't sell. I think that's because most folks have no idea what they are. If one of these was wired into a home circuit, you'd never know the power went off for some time.


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## Windy in Kansas (Jun 16, 2002)

Darren, would the internal battery bank be of large enough capacity to run a furnace blower motor all night long?


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## Darren (May 10, 2002)

I'm sure you could buy one but the cost might be prohibitive compared to something more practical. Someone else mentioned one of the small Honda gasoline generators. Five gallons of gasoline treated for very long term storage would run one for a very long time. You will have to make some wiring changes in any case. It wouldn't be hard to install a switch that normally allowed the furnace blower and thermostat to run off either regular house power or in the other position an alternative source of power whether it be a battery system or generator.

The small portable Honda generators are very quiet. I use one if needed to run the refrigerator or freezer, one at a time, when the power goes off for a long time. They look like small fat red suitcases. 

The problem with any battery system is that the batteries will eventually have to be replaced. A small generator like the Honda would probably long outlast the batteries and be the lowest cost option. I have one of the small ones I carry around the place. It will run anything you can plug into a regular 120V outlet and weighs around 40 lbs. If needed in the winter I set it outside and run an extension cord into the house. For what you need I'd probably install an unpowered outlet on the outside of the house and run the wire to the switch in the circuit between the electric panel and the furnace. With an extension cord made up with a male plug on both ends you could power the outlet and thus the furnace fan and thermostat. 

As others have said, figure out how much power you need, and we can figure out what would be the least cost option. There's a much smaller Clary UPS on eBay now, actually two of them, that would probably run a laptop for a long time. I used to run a desktop computer four hours on a Clary after the power went out. Trying to run one of the big HP desktop laser printers didn't take long to exhaust the batteries.

If I bought any of the Clarys from eBay I'd plan on replacing the batteries and figure the cost of the gel type batteries in my cost estimate. I don't know the cost of the batteries for the Clary pictured. I don't think they would be cheap for something that can crank out 25 amps. That is a lot more than you need to run a furnace fan.

To start, find out the size (hp) of your furnace fan. The other issue you may face is generators and UPS units have specific uses related to other factors than just the voltage and current draw. Motor loads are different than a computer because of the startup current under load. Someone here is probably better informed about that than I.


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## Jim-mi (May 15, 2002)

That UPS is a nice unit (tho spendy) and yes it doesn't look like the bat bank is any where near large enough to keep a furnace going for very long.

Back on your generator idea....... you need much more than just an "extension cord" . . .
Most furnaces I know of are 'hard wired' in to your home system.
And yes power needs to be supplied to the thermostat........

If you or hubby are not electricians then I suggest you get help to "modify" things so that a portable generator can be "added in"

before the snow/ice . . LOL


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## Darren (May 10, 2002)

Unless you have something bigger than a 1 hp motor on the furnace blower, you can easily and safely run off a 10 gauge extension cord. Depending on the motor size, you might be able to go down to a 12 or 14 gauge cord. I think you could easily get by with one of the 2000 KW Honda generators to run the furnace. that will provide enough power to run some other things. Honda says they can run up to 9.6 hours on a gallon of gasoline. Four full five gallon gasoline cans would allow you to run the generator for more than a week.

http://www.hondapowerequipment.com/products/models.aspx?page=models&section=P2GG&category=sq

As long as you minimize what you want to run during a power outage you can get by with a minimal cost. As far as gasoline storage I like the no-spill cans. Pick a size you can easily handle. I would rotate the fuel into your vehicle and refill the gasoline cans occasionaly to always have fresh gasoline if you don't want to use something like PRI-G for long term storage.


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## lucyp (Jan 30, 2011)

Thanks everyone. I think I will look into a small generator then and maybe a small, portable standalone solar generator for some relief on the generator. The furnace plugs into an outlet, but I am unsure about the thermostat, which is digital. I use my HVAC guy for some commercial property too and am in contact with him fairly often, so I will ask if he remembers how my thermostat is wired.


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## Darren (May 10, 2002)

The thermostat should run off a transformer possibly located in the furnace. If that's the case once you have a switched circuit for the furnace, you'll be able to power the thermostat too. Check out eBay for generators to get a general idea of pricing.


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