Home A/C Generators

[BeauV]

All,

After doing a bit of evaluation of the reliability (or lack thereof) of our local power provider (PG&E) I've concluded that I should get the Admiral a generator for the house. Please post suggestions as to what brand, fuel type, etc.... I'm all ears.

So far, I've found a 20kw GENERAC which is air-cooled and runs on natural gas. That will run the house easily and even charge the cars when the house isn't at full load. (I have yet to dig into how large a gas pipe I need.)

Auto-cut-over is important here. I'm willing to pull a big knife switch before plugging in a suicide cord, but I don't want the Admiral doing it, period.

In all this, I've been assuming that the natural gas supply will survive a power shut down, but if that's a poor assumption I'm all ears. We could dig up a diesel generator if necessary, I just don't like the smell.

Thoughts???

Beau

[Ajax]

Larry is the go-to here, but I've some things to say.

First, if your gas line reliability is a concern, you don't need to go diesel. Propane will work. Bury the tank in the yard.

Second, Have the electrician install an ABT switch (Automatic Bus Transfer.) It senses the loss of commercial power and the loss of EMF holding the armature allows it to fail over to your generator, which will start automatically. When commercial power is restored, the returning magnetic force draws the armature back, and the contacts close, allowing you to draw commercial power again. The generator will sense that it is unloaded. It will cool down and shut down. This whole arrangement protects utility workers and avoids having anyone in the residence touch anything.

It's the exact same situation with my Powerwall, except that the Powerwall doesn't need to cool down and it never truly shuts off.

[Chris Chesley]

I agree with your decision to go with natural gas. I've drawn the same conclusion. If natural gas becomes unavailable, well, you've got a whole 'nuther set of circumstances.....

Propane is a good second choice with an underground tank setup. I look forward to hearing recommendations as well.

[Jamie]

I've been to the Generac plant. Decent stuff. China parts, assembled in the US.

My parents have it run off a propane tank with an ABT switch. They have the mission critical items on a separate circuit to keep loads down. Being Maine, it runs a a couple times a year for up to a week or so. It self-tests once a month.

[TheOffice]

Beau,

I have not looked into these in 10 years or so, but a number of my neighbors have Generacs running on propane (no natural gas where we are). When I looked at them I concluded we could get buy with a 12 kw. I think we had 100 amp service. If you've got 150 amp service, then 20 kw should be plenty.

[LarryHoward]

I have had a Generac 20KW unit with an auto transfer switch that runs my entire house for the last 10 years. It is fed by a 550 gallon underground tank that is sized to provide us 1.5 weeks of power without significant conservation when the tank is about 70% full. It's installed about 25 feet from our bedroom in the edge of the woods and is quiet enough that we can sleep without a problem. We have had 2 failures, both covered by warranty. Once was a fuel shut-off solenoid valve that failed during an outage. Not a happy failure. The second was a main control board. Replacement parts were new part numbers so they seem to have a reasonably robust response to failure prone components. My is about 30' from the water so gets some brackish spray during storms. Corrosion has not been a problem. Service kit for the engine is $25 on Amazon plus a quart of oil. Starting battery lasts abut 3 years. Cost, with buried propane tank and an initial 500 gallon fill, was $10K in 2010.

We installed the Generac auto transfer switch. with load shedding capability on 3 circuits (both HVAC units and the hot tub) to ensure we don't see a frequency drop pr overload the generator). I have it set up to run 20 minutes each Saturday at noon to exercise/self test. Annually, I force a power failure condition (shut off the incoming power) to exercise the auto start and transfer functions. Once it warms up, I add load until I have it running over a solid load (10-12 KW) and run it for about an hour then restore mains power and let it disconnect, cool down and shut off.

I love the thing. 6 months after we installed it, we lost power for 9 days following Irene. We generally went into a conservation mode and shut things down when our (then 16) son left for school around 0730. When he got home at 1530, he wold start it and turn on AC in the front of the house. We would get home around 5 and go into down tree clean up mode until dark, get hot showers, have dinner and we would soak out tired muscles in the hot tub. We would shut down the "living zone" HVAC about an hour before bed time and turn on the "Sleeping zone." Rise and repeat. That consumed an average of less than 20 gallons of propane daily, so about $50/day. Since we are on a well, power means water and without it, we would be off into a hotel (two rooms at $125/day) so cost was about 20% of a hotel stay, we didn't lose the frozen food and were there for clean up activities. The Auto start and transfer functions were priceless when I was out of town and just Lynne and the kids were home. Power dies and 20 seconds later the generator fires up and by 30 seconds, the lights are back on.

Diesel generators are more robust and cheaper to operate but cost a lot more. Add in a propane or gas powered ICE is quieter and pretty clean burning, requiring minimal maintenance

A large Powerwall is 13.6 KWH max. That will take care of short outages and with some solar contribution, keep your freezer cold and some of the lights on. The propane generator will run my entire house as long as I need it. You do need to feed it propane or NG at some cost. If I lived in a more urban area with less risk of power loss and extended outages, I might make a solar/Powerwall decision today. 10 years ago, options now available were not there.

[SemiSalt]

Folks with gas or diesel generators have a fuel problem. It's hard to keep fuel in stock and fresh, and when the power does go out, it's hard to buy fuel (because everyone wants fuel). So, gas of one kind or another is best.

Are you really allowed to bury a propane tank? I think the rule might vary with location.

[LarryHoward]

Semi

Good point on gasoline but I have found diesel kept moisture free and treated with biocide to be stable for more than a year. A bigger issue is that diesel or gasoline engines don’t burn as cleanly as NG or Propane so those engines do require additional maintenance.

We can still bury propane tanks here.

Beau. For your “wants” including auto transfer and whole house usage, I feel pretty good about recommending the generac and auto transfer switch. Some things in the NEC may require some reworking of your load panel wiring to separate common and ground as Code calls for them to be separate from each other after the initial entry into the house. The ATS becomes the new initial entry according to my local inspectors. That nuance cost me 8 hours of a licensed electrician’s time.

[Olaf Hart]

We went through this planning exercises with the play house rebuild, we are on tank water from the roof and have a septic system.

When our power is out where we live, which happens rarely, our main problem is the water system, so no water for the sink, bathroom or more importantly the toilet cisterns.

We have a wood fired heater, and also a gas BBQ so we are fine for heat and cooking, but no hot water.

So, we have installed a small tank that collects roof water with a sump pump that pumps it up to two large holding tanks about 20’ higher than the house. When it rains there is generally power for the sump pump, if the power is off we bypass the house pump and there is enough pressure for taps and cisterns.

There is also enough pressure for fire hoses, although we do have a Honda powered fire pump as well, the power is usually off in bushfires.

When the carport is done we will put in some solar and a battery, so there is enough power for lights and electronics via an inverter.

No need for a generator, only cost is no hot water, although if power outages become a thing I do have a gas flash heater I could install. There is usually enough hot water in the tank for short outages.

[BeauV]

Thanks guys. I'll keep looking into the Generac. It gets good reviews from my local guy. Also, asking them about the 1" gas pipe we have from the street. If that will run the thing, then we're good to go. But, I'm guessing it'll need its own "t" in the 1" line. More as I learn more.

One more thing, gas from the main will probably be off after a big earthquake. It'll certainly be "off" in the house as we turn it off as soon as the earth stops moving. Broken pipes are what burned SF to the ground in 1906. The main feed has stayed on in small earthquakes, below 6.0. More to learn about all this.

[Ken Heaton (Salazar)]

Generac is one popular supplier to the residential market. Kohler is another: http://www.kohlerpower.com/home/home-ge ... generators

We have many Kohler Diesel Generators in our Municipality as backup for some buildings, (Police Stations, City Hall) and many more for Water Treatment Plants, Water Pumping Stations, and also for Sewer Lift Stations. Many we've had for 20 or more years with few problems.

We have a small Kohler (5 HP) that runs on propane as a back up for sump pumps to keep a boiler room from flooding in an outage (there is a spring under the building). It must be 40 or more years old and still runs like a charm.

[Chris Chesley]

Beau, silly me! I hadn't even thought about the earthquake angle. In that light, it seriously changes how I'd feel about the natural gas choice for a back up generator in your neck of the woods...

[BeauV]

Ken, thanks for the reference on Kohler. I've been looking at those too. It is VERY hard to get any quantitative data across a large pool of units, thanks for your input!

B

[kimbottles]

Beau, silly me! I hadn't even thought about the earthquake angle. In that light, it seriously changes how I'd feel about the natural gas choice for a back up generator in your neck of the woods...

I really like my 12KW Honda diesel generator, unfortunately they discontinued making it sometime ago.
We have had as much as several days without juice, so it is popular with Susan during those outages.
(Manual connect and very simple. Rotate the extra diesel through the diesel Touareg so storage isn’t much of a problem.)

[BeauV]

I’m not sure where to post this.....

There are fires breaking out all over the place. Fortunately, not near us in Santa Cruz (yet).

Interstate 80 is closed, the fire burned up to the edge of Cal Maritime, north of us has been under mandatory evacuation from Santa Rosa to the Pacific Ocean many miles away, peak wind speed measured in SF today = 90 knots, peak wind speed measured in Sonoma County 101 knots, and it’s going to get worse on Tuesday.....

Frankly, we’ve never seen anything like this. It’s a horror movie in the real world. My ancient Great Uncle has been moved from his rest home in Windsor (which is burning tonight), to Santa Rosa, then when it was evacuated to Scotts Valley about 5 miles from us. He is ancient and confused. We’ll go there in the morning to console him.

All the rainfall of last winter caused a massive growth - it’s all burning now.

[Panope]

Holy shit.

Stay safe Beau.

[Ajax]

Pack "go bags" and be ready to move. I hope the fires don't get down your way.

[kdh]

I'll hope for the best, Beau. Take care.

[TheOffice]

Beau,

Sounds absolutely horiffic! When we were Sonoma two years ago we could not believe how thick the underbrush it. The whole area is a fire waiting to happen. Stay safe!

Joel

[Benno von Humpback]

Must be very scary indeed out there, Beau. Our thoughts are with you and everyone else facing this ongoing disaster. I hope some kind of mitigation is possible, otherwise, I suppose, large areas are going to become uninsurable.

[JoeP]

Yes. Very scary. I have a cousin who lives around Sebastopol (sp?) and has a business in Santa Rosa. I have not heard from him but I surmise he and his family were evacuated. If something did happen I am sure I would have heard it through the family grapevine. Luckily if worse comes to worse they can stay in his father's house in San Francisco which is empty because, unfortunately, his father passed away recently. Tough few months for him.

[BeauV]

The big fires are still burning and we've now got at least 10,000++ homes in the "line of fire", so to speak.

Fortunately, the weather has calmed a lot but it is forecast to pick up again tomorrow. Hopefully, the firefighters can get a grip on the fire line during this lull. They have about 24 hours. Tuesday night, the Napa airport is supposed to go back to 40+ knots from the north, hot and dry. From about now to Tuesday around 8 pm the winds are light and variable.

In our Santa Cruz mountains, Tuesday night will only reach 20k winds in the gusts. That's a LOT less than the last few days. I think we'll be fine.

[BeauV]

Regarding the brush, or as the firemen call it: "The fuel load", it is quite heavy because of the 187% of normal rainfall we had last winter. This was at the end of a multi-year drought, which killed a number of trees. As a result, you've got heavy undergrowth beneath a lot of dead trees. It's a bad combination.

There are three things that need to be done around here and throughout places all over the SW of the country to deal with this.

1) Folks need to understand that they can't live under a tree canopy unless they live in the depths of a redwood forest or someplace damp. In the oak, fir, and pine tree-studded areas living under trees is a slow form of home suicide. Eventually, a burning tumbleweed or branch from a tree will be carried by the wind and dropped into the canopy, then everything goes up like pine-sap fueled torches.

2) Folks need to understand the risks of living in a semi-rural area with limited access, like one 2-lane road, no real fire fighting support nearby, and a LOT of brush and forest. Yes, it's nice to pretend to live in the country, but it is a massive risk to not only the homeowner, but their family, pets, and the firefighters who have to come to save their scalded asses.

3) Finally, anyone who builds infrastructure which can start fires needs to know they are going to have to pay for the consequential damages if things burn. This is not only PF&E power lines, which has recently become obvious, but also roads, farms, oil wells, etc... We have had massive fires and killed dozens of people in fires which caught because some county decided not to mow the weeds next to the road. Similarly, some guys in the hills behind my Dad's old house set the hills on fire and caused the destruction of over 100 homes back in the late '80s because they dropped some hot tool in the grass as they were working on an oil rig. Each of these organizations needs to suffer the financial consequences of their actions or negligence. Getty Oil and Kern County did end up on the hook for the consequential damages, just as PG&E is now. But cultural learning hasn't happened. The Board members of these companies need to have it drilled into their skulls.

If we do these three things, the fire problem gets MUCH better. As it is, our home has what is effectively a fire brake 100' wide all the way around it. There is very little foliage that is anywhere near the building. We never allow any leaves to build upon the roof. While the roof is a wood shake, it is sprayed every year with a fire retardant which seems to work. I've sprayed the stuff on a piece of cedar shake and then tried to get it to burn a month later, it wouldn't catch.

[avramd]

My $0.02 worth here is that natural gas supply can not be taken for granted.

I converted both of my houses in Newport to gas in 2013. I've been without heat a dozen times since then. So far, there have been two reasons for it:

1. We get water/vapor in our gas lines, and then if it's really cold, it freezes in the outdoor meters, and chokes off the gas supply. It's stupid that they put the meters outdoors, but they insist on it.

2. We had a week-long gas outage in Newport last winter, conveniently when it was 3º out. It was a supply error. It took a week to restore b/c they shut off every single house by hand, and then turned them back on by hand. They were worried that if someone had a pilot light out, and didn't understand what was going on, then their house would explode.

Long story short people and systems can both fail. If you have something that you have to have filled up regularly, then the opportunity for failure is isolated, infrequent, easy to identify, and fairly easy to avoid having the failure happen at the worst possible time.

[BeauV]

Interesting comments - thanks.

Here where we live the temp has only been below 32°F once or twice in the last 20 years, and then only for a few hours. The vast majority of the plants in our yard will die at 28°F. As a result, we quite literally never think about someone freezing our gas meter. Ours is outdoors too.

We do, however, have earthquakes that cause the power company (the evil PG&E) to turn off the electricity and the natural gas to avoid fires.

As a result, the generators I've looked at recently have natural gas feeds for their primary source of power and can be run from a propane tank if the main gas line is shut down or broken. It looks like we could have a natural gas generator for the vast majority of electrical power failures and have a couple of 100 gal. propane bottles for the very rare earthquake.

[SemiSalt]

2) Folks need to understand the risks of living in a semi-rural area with limited access, like one 2-lane road, no real fire fighting support nearby, and a LOT of brush and forest.

There was an evacuation order for Brentwood. And the Getty file is about 2 miles from my daughter-in-law's lab at UCLA.

[BeauV]

Semi,

Fingers crossed for your daughter!

Up here in N CA the mandatory evacuation now runs 50+ miles to the Pacific Ocean. We’ve never had it this bad. Just to torture the folks sleeping in their cars and tent while they wait to get back to their home, we have a cold from rolling in which will take the low temps inland down to the mid-20s.