whole house generator ?

[GaryMc]

We are finally biting the bullet and installing a whole-house generator (400 amp service - a 20Kw or higher).  3500-sq. ft. sorta high-end house is 32 years old, with heat pump backed by gas furnace.  The estimator who did a more thorough inspection than the others included looking inside the two 200-amp main service panels and noted rust and slight corrosion in the breaker connections and suggested replacing the panels.  The panels are inside the basement which is about half-underground and the 12-inch block wall has never leaked, so the problem likely is due to the higher humidity in the basement over the years.  He also suggested that the old gas meter and electric meter, which are outside, also may need a look-see from the power company for possible replacement or upgrade in the feed lines (which are buried from the street) or whatever.  His estimate included all of this stuff.  The other two estimates did not include any of the extras.  Result - about double the "base" price.

After all these years we want to do this right THE FIRST TIME, and whole-house versus partial service is somewhat related to resale value (we would not need to run the oven or my power tools or the dryer during an outage, but the next guy may not be so inclined).  So I would appreciate any thoughts any of you may have about all of this.

Gary

[Cabinet Monkey]

I’ll offer my perspective and thoughts/opinions. 

20kW prob. isn’t enough to run 400a service, so “whole house” is not realistic  but the pro’s should have a good handle on it. 

You’re gonna need a panel swap/ change / upgrade / add/  re-wire just to utilize the generator anyway.  Ideally you’ll wire one panel as the generator and the other as not.  There are a few panels that are /have the transfer switching built in.  

Ask for or look at what the cost of the generator , x-fer box, and new panel are to compare against the others.  All vendors should be providing the same basic spec.    Service upgrades will be required to do the project for all vendors or they won’t.  They should be done by the utility providers and the cost is the cost.  The generator guy has NO BUSINESS replacing your gas meter.  

This is not really a necessity, but a luxury.  Ask yourself / check what the longest your area has been w/o power when you do the mental calculus.  The system will offer you no payback under most circumstances- even at re-sale.  It may make your place more “marketable” but it would be very surprising if you actually realized a return on the capital cost of the system and work.   Especially in a down market.  

Don’t underestimate the ongoing cost of having a standby generator.   They run weekly (use fuel) need oil changes, and the batteries have to be replaced regularly so there’s no chance of it not having charge to start when needed.   Car batteries ain’t cheap.

[GaryMc]

I’ll offer my perspective and thoughts/opinions. 

20kW prob. isn’t enough to run 400a service, so “whole house” is not realistic  but the pro’s should have a good handle on it. 

You’re gonna need a panel swap/ change / upgrade / add/  re-wire just to utilize the generator anyway.  Ideally you’ll wire one panel as the generator and the other as not.  There are a few panels that are /have the transfer switching built in.  

Ask for or look at what the cost of the generator , x-fer box, and new panel are to compare against the others.  All vendors should be providing the same basic spec.    Service upgrades will be required to do the project for all vendors or they won’t.  They should be done by the utility providers and the cost is the cost.  The generator guy has NO BUSINESS replacing your gas meter.  

This is not really a necessity, but a luxury.  Ask yourself / check what the longest your area has been w/o power when you do the mental calculus.  The system will offer you no payback under most circumstances- even at re-sale.  It may make your place more “marketable” but it would be very surprising if you actually realized a return on the capital cost of the system and work.   Especially in a down market.  

Don’t underestimate the ongoing cost of having a standby generator.   They run weekly (use fuel) need oil changes, and the batteries have to be replaced regularly so there’s no chance of it not having charge to start when needed.   Car batteries ain’t cheap.

[GaryMc]

The quote did give a complete breakdown of the individual cost of various items and services, and the estimate included coordination with the power company, NOT doing anything with the meters/service themselves.  Also, we would not expect a full ROI for whole-house installation, just somewhat of a selling point as noted - many of the neighbors have whole-house units albeit with less power input than in our case - typically only 200amp service (knowing them, they would NEED to run the oven during an outage 
.

The power has been out here (SE PA) frequently and for as much as five days - both in July and January and a few times when we were on vacation and could not run the little portable to keep furnace heated or fridges cold - and the security system charged - as we did on other occasions.  Interesting is that all the utilities in the neighborhood are underground but the feeders from substations are on poles surrounded by huge trees along the roads.  It only takes one errant limb and if the outage is widespread (like during those 5-day stints), then we are way down on the priority list.

We also understand this will be a bit expensive to install, run and maintain, but at this stage in our lives we are tired of cutting short long-planned activities (most recently a rush-back three weeks ago when the power went out and the temperature was hovering just above zero F), not to mention the aggravation of dragging the portable outside and stringing up to 10 gauge wire all over the house to power just the necessities.  BTW, that "double" estimate also included 5 years of maintenance and a whole-house surge protector and a few other amenities.

And yes, I did see the deterioration in the service panels that the estimator pointed out.  I had never had either of those off before except several years ago to replace a failed circuit breaker.  I think if I were a home inspector I would point the condition out as a default.

Apparently the greatest concern of the estimator re power was the possible condition of the gas/electric meters, being outside, somewhat rusted and 32 years old.  He only wondered about the gas line sizing because of the added generator load on the furnace, water heater, and cooktop.

[jteneyck]

I had a whole house generator installed about 7 years ago after a 23 hour outage when it was 90 something degrees outside and I wasn't home.  I would do it again in a heartbeat even though we haven't been w/o power for longer than about 6 hours since.  I call it my $7K insurance policy.  

Portable generators are an unacceptable solution to me.  They are of no value if you aren't home, and that was my greatest fear.  What happens if I lose power in the Winter and I'm away on vacation?  Or during the summer and we get lots and lots of rain.  No sump pump, not good.  The potential downside is far more than $7K. 

You likely will need a gas meter upgrade.  It has to be sized to supply enough fuel for everything that would need gas during an outage, which means both your furnace and the generator, and likely the hot water heater, too, if that's gas.  I had to get an upgrade.  It cost me about $200, maybe $250.  The gas company does that.  

Maintenance is not a big deal.  I do almost all of it myself, which typically involves changing the oil once a year, and the air filter and spark plugs every two years, unless there were a lot of run hours on it from power outages, which we've never had.  I paid to have the valves reset once, and I changed the battery once after about 5 years.  The battery cost less than $100.  Even if you pay for yearly maintenance, it's not that big an expense considering the piece of mind.  

The generator has worked w/o fail every time we've lost power, and life goes on uninterrupted.  With UPS systems on key electronics, I don't even have to reboot them.  

John

[blackhat]

400 amp service or 200 and one panel is a sub?  Gas service/meter will likely need up sized for a 20 kw but I see upsell when he starts going on about elec upgrades. Did you see corrosion in the panels and specifically on connections and buss bars?  Again, my feelers are twitchy. No idea about the layout of your house, yard and utilities but I’d like to know the answer to what the electric service is before adding much more.

[fredhargis]

We had a 22K stand by installed about 3 years ago. At the time that was the largest you could get in an air cooled unit, I think now they have a 24K model that's air cooled....beyond that it's water cooled and that's really big bucks. Like John said, the maintenance and upkeep isn't a big deal. Mine runs on LP, and the 15 minute weekly exercise is almost imperceptible in terms of cost. But if you loose power for an extended time, they can really suck the gas. I noticed mine has the oil change interval called for every 2 years (or xxx run hours), but so far I've been changing it annually...not a big deal. Neither is the air filter. The battery I buy is about $120, and i replace mine every 2 years. Overkill, but my genny sits out in the sun, and the thing really bakes in the summer...heat destroys batteries fast. I rather spend the extra money than have it not start when it's zero degrees outside. I've had the valves adjusted once (after 25 hours, I think) and now it's an every 200 hours or so job. That cost $120. One thing, my generator is a Honeywell (Generac), you might check the maintenance requirements on a Kohler to see if it's significantly difference (like the valve adjustment), I doubt it is but it wouldn't hurt to check. As for what we can run with it. Our house has a 60K heat pump and if the generator is running it will draw it down on start up....but the generator can support it just fine past that. The 22K is 100 amps, and that's plenty for normal day to day stuff.

[EdL]

A friend had a whole house unit put in a few years ago, 12-15k size.
His gas service was a new install (long story) he did have to pay extra for the larger meter/regulator to handle the generator.

Ed

[R Clark]

We upgraded our backup power generator in January 2019.  Like the OP, we have 400A power feeding two main panels side-by-side.  Sub panels off of the mains are the shop building and the maintenance shed.  The former backup power generator was a permanently installed 7KW unit with a Briggs and Stratton motor.  It was manually started and switched, and the unit was anything BUT reliable.  Switching that old unit was literally a 13-step process which was performed in reverse to switch back to commercial power.

Our generator is a 22KW Generac with automatic switching.  The left main panel is the panel powered by the generator.  All of the circuits in the left panel are energized when backup power is feeding the system.  The right power panel only has some ancillary circuits in various parts of the house, and most of them are not in use an a daily basis.

Our generator dealer is a licensed local electrician and he was the installer as well.  As part of his installation estimate, he included the work to move all of the desired circuits from the right panel to the left panel, and the moved unneeded backup power circuits from the left panel to the right. 

Our generator is propane-fueled.  Before installation, I had our propane guy upgrade the propane line to the generator installation site.

While our model generator is often sold as a "whole house" solution, it's not really a whole house solution in my mind.  First, it does not power all of the circuits in the house.  If the circuit is in that left main panel, then it can be used when on back up power.  Second, all of the "heavy hitter" circuits are in that left panel.  Heat pump, double wall oven, water heater, and the circuit that powers the subpanels in the outbuildings.  If all of the circuits that are in that left panel were going at once, the generator would suffer from demand overload and could be damaged.

There is a load-regulating device that sheds load that the generator guy could have installed.  I did not buy that option.  Only my wife and I live in the house, and rarely, if ever, would we run so many circuits at one time.  I have done things to configure the house to be more compatible with that backup generator.  For example, when we replaced the the old heat pump and electric aux heater in 2018, I moved to a heat pump over propane aux so that the HVAC could run regardless of power source.  I also recently replaced the old failing electric hot water heater with a new heat pump unit that has reduced power demand.  Heat out in the shop building is propane fuel and requires 110V service, not 220.

Like John said, maintenance is not a big deal.  I do the oil changes and valve adjustments as required.  I have not had to replace the battery, yet.  I did not buy Generac's extended warranty.

[goaliedad]

Not a whole house situation here- but I will share my experience

I was looking at 10K units. Salesman told me 8.5 would do what I wanted. He did not have any in stock, but told me where I could find on locally. That impressed me. The original guy was usually doing larger, auto start stuff bi got the feeling he did not want to be bothered with my little baby system, but was very helpful and I did not feel like he was blowing me off.
I wired an exterior plug in and a safety interconnect so all I do is out the unit out of the garage and plug in the cord. Turn off the main breaker, move the interconnect and flip the generator feed breaker on. The generator has battery powered electric start.
We have had a couple longer outages- 30 hours. I keep a stock of rec gas on hand.
The unit has done what we need. Lights, fridge, freezer, shallow water well, forced air furnace and electric water heater on one outage I did not realize dear wife was doing laundry. When running the electric drier and the water well kicked in the breaker would trip. She now understands that clean clothes will wait.
We are in propane for heat and range. We now have an on demand water heater (gas) for in floor heat. We also have central air, but rarely use it. I would not try it on generator power.
I have a very good neighbor that will fire it up if we are gone