Whole House Backup Generators

[cpalmer2k]

This is kind of a spin off of a couple of existing threads dealing with the California power outages and other issues but I'm curious to know how many on the forums have a "whole house" backup generator? Do you like it? How "big" do you need to realistically go to power an entire house, and did you go with an automatic or manual transfer switch? Interested in hearing from others on this as it's something I have been thinking about doing for some time now. We live in the South but the power outages during ice storms and just randomly during the summer months seem to be getting more frequent. We have a great natural gas provider where we are, and that is actually our cheapest utility. A lot of my appliances already at least partially run on gas as well, so I'm hoping that would help reduce the "load" on the generator. We've got a tankless gas hot water, a gas dryer, and a hybrid stove. All of those primarily use gas, but do rely on some electrical power to operate. Unfortunately our heat & air is full electric, which I know would require a bigger generator.

 

[harshness]

Whole house generators are often a matter of safety if you have medical equipment (CPAP, oxygen concentrator, etc) or other devices that can't reasonably survive an outage. If you have tropical fish or something similarly dependent on pumps, a generator of some sort is a must but most systems can be run off a small generator. It also comes down to how ambulatory the residents are and how long your power is typically out. If you can't survive without air conditioning and the power goes out when it is hottest, a whole-house system is a must.

My neighbor who is in his 80s recently had a system installed. He doesn't have access to natural gas so it runs on diesel. Maintenance is a major concern with a diesel unit. Remember that whole house units require a house call to service so if you have tough environmental conditions like salt air or high humidity, this may get costly. Bitter cold can also be a concern but I don't imagine that happens in "The South".

We annually have outages that last more than four hours and once every five years there's a 12+ hour event. Every 20 years we have a 25+ hour event. If your events last no longer than a couple hours, I don't really see a point and power banks (lithium batteries with inverters) may be a better solution to cover the critical stuff over short intervals.

My own concern is my well pump and the big freezer and refrigerator. I could replace the contents of the freezer for less than the cost of a modest portable generator. For my purposes, I have a Yamaha "2,000 watt" inverter. It won't run my well pump but it will keep everything else going with some running around. My gas cooktop is fully mechanical and I have a mechanical gas fire log in the fireplace.

Experienced local generator installers are perhaps best suited to take your local power and environmental conditions into account.

 

[primestar31]

I have a 6KW Gillette diesel generator, (not autostart though it is electric start) and it can pretty much power my house just fine. It's hooked into the panel with a transfer switch. I have hot water natural gas boiler for a furnace, natural gas hot water heater, and city water. So, there's not really any one thing that takes a HUGE amount of power to run.

It was a $4000 dollar generator 20 years ago, but I got it in an estate auction 19 years ago with 2 hours runtime on it, for $1000. It now has about 160~ hours runtime on it, so it'll finally be broken in, in about maybe another 5 years or so, lol.

P.s. At my previous house this same generator ran my 220 volt well pump, water softener, and forced air gas furnace, and every else just fine with no issues. Oh, though I never tried it with the Central air also running with the rest, as that would just be stupid when fans work for emergencies.

 

[Radioguy41]

I have a 5Kw electric (battery) start wired thru a manual 3-way (Line, Off, Gen) switch. Two circuits power the well, the other four power the furnace, fridge, and a couple of light circuits, all we need to get us thru.

 

[arlo]

Gensets up here where I live on REC are common. It's quite easy to determine the gen you may need.
Take the nameplate current draw from everything you may need to power in an outage. Add it all up. Include light wattage. Minimal if you have LED's.
Add it all up. Give it a margin in the upper range. If budget is a concern you may think about things like higher current appliances.
Maybe you will need to run the washer, dryer, cook on the stove (a camp stove and good old fashioned percolator coffee), and other stuff.
With a smaller generator you might want to shut off everything else while you use them. An electric oven and electric clothes dryer may be out of the question.
As far as a well pump goes, submersible. 1 horsepower equals...errr...745 watts. A little over 800 for startup.
Some folks here swear on Honda generators. Whisper quiet, inverter based. And you can tandem them and use a bulk gas can to feed them. Great on gas.
Other's of course have the whole shebang Kohler natural gas generators. Auto start and transfer switch equipped. Power outages are a blink of the eye for them.
Me. A cable that reaches from the twist lock on a 5kw and plugs into a welder outlet in the garage. A flip of the main breaker, and do some math. Then wait for the yard light to come back on.

 

[harshness]

Electric motors don't behave according to Ohm's Law on startup. The starting draw on my 1.5hp well pump is 2,800 watts. I could mostly cure the inrush by using a variable frequency drive (controlling the ramp-up and speed of the pump).

Of course most submersible well pumps are 220VAC and that requires a big-boy generator with a 220VAC outlet.

Sump pumps can also draw quite a bit of current and you absolutely want to cover them with any generator you might acquire.

Most of us don't need our home to be fully functional when off-grid but for those who do, there's some serious planning involved and long-term monitoring can provide valuable information about needs.