What size generator do I need?

[gtone]

Have a 1100 sq ft home with no A/C, looking for a modest sized generator for emergency backup use as our provincial power grid is really showing cracks recently. We have gas furnace, water heater and fireplace for backup heat source, latter would keep our pipes from freezing at the very least in the event of power outage (only the circulation fan wouldn't run). Basically need enough juice to run lights (mostly LED), fridge, smaller deep freeze, maybe odd appliance here/there (only wife and I here), maybe some electronics (TV, computer, etc).  How many watts would I need for this purpose?

TIA for any/all help...

[killerteddybear]

The easy estimate calculation is to take the total amp rating of your circuit breaker panel and divide that figure by 8 for Kilowatts.

So, a 60 amp service would require a 7.5kW supply, and a 100 amp service would require 12.5kW.

Those figures assume you are consuming a full 60 or 100 amps! The reality is that you're likely using much less than this and could probably get away with a smaller generator.
What you could try is pull out your SaskPower bills and look at your monthly consumption in kilowatt-hours; if you're lucky they'll have the usage broke down by day, otherwise divide the monthly number by the hours per month (720 hours for 30 days).

You may want to consider solar assist. God knows there's plenty of sunshine in Saskatchewan, and no hills to block the rays...😆😆

Last minute update - the internet says 5kW to 7.5kW should be plenty for your situation.

Finally, Canadian Tire in Moose Jaw has a Champion generator 6.5kW on sale for Canuck $700. You're all set!

[benjammin308]

If you want an exact number add up the wattage of the appliances that you want to run and you have your number.  Generally speaking 5kW to 7.5kW covers most household needs, just make sure you are looking at the running watts and not the starting watts on the generator.  Different generator manufacturers label them differently, there is no standard.  Also make sure you get one with a four prong locking receptacle, usually labeled "120/240 volt" or "NEMA L14-30".  This will make it easy to power both your 120 volt and 240 volt appliances with a single connection.  The real question is how are you going to get the generator power safely connected to your home?  Send me a message when you are ready, it's what I do.

[Thundersteel]

1.21 Gigawatts!   

[duncans]

If the gas for your furnace is natural or propane make sure the generator can adapt to that as well. No running out of gasoline!

[DaveH]

I made an 8kW (10kW surge) setup for my house (1150 ft2). It has a LP conversion, and runs everything I really need except for a clothes dryer and central HVAC. It does run the mini split unit in my shop tho... It gives me lights, hot water, cold beer, microwave, a stove eye, fridge / freezer, and hot coffee. I was recently out of power for two days, and it used roughly half of two 100lb LP tanks (keep in mind an outage a couple years ago that lasted 5 or 6 hours, and periodic fireups / 20 min runtimes to exercise the gen is also included in that.) 

As stated by others, add up the power requirements of everything you intend to use at one time. Keep in mind that simply adding certain loads won't account for startup requirements which are different from running requirements... Although a 10kW portable won't start the compressor on a typical central HVAC unit (it does run the blower), it will run a small mini split or a window unit.

My project came about because of past outages which lasted anywhere from 1 to 5 days, where I had to drag out a portable gen, haphazardly set it up in the elements while trying to protect it, etc. It sucks. What I have is MUCH better than that now, It is back-fed thru 2 separate breakers in two panels, and a Main to isolate from the service. I'll post pics in a bit.

Disclaimer: If starting from scratch, I'd go with a standby set which can be had for $4-5k w/ATS, but if you already have a decent gen this is not a bad way to go. Remember to ground!