Some general propane/NG generator questions

I live in New Jersey but this is for a friend of mine who lives in Virginia in the suburbs near Richmond.

She lives in a 4 BR single family home in a development which (in case it matters) is governed by a homeowners association. She seems to have at least one or two major power outages a year due to summer storm damage, as well as winter snow storm damage. The power outages are almost always caused by wires down in her area from falling tree limbs etc., and her area is almost always one of the last to get their power back on. When she has a power outage, it is often for several days up to a week or more. Her home is all electric -- meaning electric heat pump, electric central A/C, electric hot water, and electric stove/oven etc. None of the homes in her area have natural gas service, but she believes that there may be a natural gas line that runs along the roadway behind her house. So, one possible option may be for her to get a natural gas connection to her home from there, and she is going to ask the natural gas utility company about that.

Due to the frequency and length of the power outages, she is considering getting a back-up generator system installed. One option seems to be to get a propane generator. And, I think that it may be a good idea to have it connected by an electrician to one of those manual switch-over (cross-over?) breaker devices in the main electric panel. Then, if there was a power outage, she could do the switchover to the generator power and not be without power for days on end.

Here are a few of my questions:

1) Can anyone give a rough idea of the size (wattage) propane generator that she may need? She probably would only need some basic items powered, but I wonder what she would need if she also wanted to be able to keep the heat pump on in the winter and the central air on in the summer, plus some lighting, the refrigerator/freezer, etc.

2) How long will the various size propane tanks last before needing to be refilled? I know it depends on the tank size as well as the power rating of the generator. However, she is retired and she probably would not have the ability to lug around propane tanks to get them refilled, especially during a snow storm. So, I am guessing that some type of larger tank that could be refilled on site by a propane supply company may be a better option -- if that is a possibility.

Any general ideas, information, or suggestions would be appreciated.

I will reply back with additional info if needed.

Thanks.

Reply to
TomR
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Per TomR:

3) For larger tanks, how does one know how much fuel is left in the tank?
Reply to
(PeteCresswell)

The heat pump is probably the largest load. The eqpt will have a label that will tell you the actual data, but I'd guess typical could be in the range of 30A, assuming that electric resistance supplemental heat is disabled. So, that's 7200W right there, with more needed to get it started. Electric water heater is probably next large load, if she can get by with just the water in the tank and not heat it, that would reduce the load. Also, depends if she's willing to manage the loads so that they aren't on at the same time or wants the possibility that they are all on, etc. I'd say she's probably looking at ~~15KW unit. You can probably get by with smaller, but the cost difference for say a 15, vs a 10 isn't that much. Especially when the cost of installation of gas lines, propane tanks, etc is involved. The grill sized tanks aren't going to last long running a heat pump. You can probably figure out the run time with various size propane tanks by looking at the generator specs, how much fuel it uses, etc.

Reply to
trader_4

On 7/17/2015 10:03 AM, TomR wrote: CY: Text inserted after my initials.

CY: I'd want to check first with the HOA about the whole matter. It is very possible they will prohibit any thing.

She seems to have at

CY: Week is a bit long, to be without power.

Her home

CY: That's a bad choice, to move into an all electric house in a HOA. Not much to be done now, but advice to all who are looking to buy a home....

None of the homes in her

CY: Other option is a propane tank on site. If the HOA will permit, that is.

CY: Transfer switch is a good idea.

Then, if there was a power

CY: I like the concept.

CY: Based on what you want to operate.

She probably would only need some basic items powered, but I

CY: Well, see? Not enough info. Some of the generator companies will have that info.

CY: Right, some companies will put in a tank which they own, with the understanding you buy propane only from them. Some companies price cooking gas differently than heating gas. You might also be able to put in propane furnace, which might be cheaper than heat pump.

CY: I suspect your HOA will veto the entire idea.

CY: Can't think of much. Yellow pages is your friend, call and see if you can find a company that makes sense. It is also possible your friend may need to do indoor things like flashlights and portable free standing propane heaters, to stay out of sight of the HOA.

Reply to
Stormin Mormon

Typically there is a round gage that gives a general idea.

Reply to
Stormin Mormon

There are at least a couple web sites out in the ether, which deal with these questions. My experience with winter power cuts, they are miserable. My own answer is to wear more warm clothes, run the gas range in the kitchen. After dinner, I run a wire from my natural gas furnace to a small generztor, and run for an hour before it gets too late in the eveing. That makes night and sleeping so much better. Very little of this will convert to your freind's house in the HOA. Wish I was more help.

Reply to
Stormin Mormon

I don't know about the cost of propane, but if it is anything like gasoline going to a big generator might not be a good idea. A 15 kw unit will probably suck a lot of fuel. While getting the fuel might not be a problem, the cost may be.

Reply to
Ralph Mowery

The OP did mention power cuts and storms. During such moments, some times fuel becomes unavailable, as the gas stations cannot pump. Less sure about propane. But, if trees are down, the delivery truck may be unable to get there. Trade offs, with any system.

Reply to
Stormin Mormon

Years ago, I ran some numbers on gasoline power generators, using numbers from sales catalogs. How many hours at half load, gas tanks size, and so on. If memory serves, I figured a gal of gasoline produces 4000 watts for one hour. Propane has less energy than gasoline. If this SWAG all works out, figure 4 gals of propane for one hour of wide open throttle on a 16,000 KW unit. A 100 gal tank (filled to 80 gal) would then be 20 hours of wide open throttle.

Reply to
Stormin Mormon

First step is to find out if the HOA will allow a generator.

If no, we are done.

If yes, on to the next step.

If the gas is only going to power the generator, she will pay a lot of money if the utility will even consider it. They do things for cheap if you use a lot of gas. I was able to get a gas line brought into our building, but our typical gas bill runs $10,000 a month. Your friend will use $10 a year so don't expect a warm welcome.

Propane is an option, but check that HOA again. They may have a limit on what you can have.

Next, determine what you want to work during the outages.

Go the one of the web sites by the generator makers and they have information to help you choose the size you need. Do some research to find a reputable installer

Reply to
Ed Pawlowski

How much does propane cost to fill the tank ? If anything like gas even running with not much of a load the 16 KW unit will use a lot more than a 5 KW unit. If your numbers are anywhere close and even if the generator is not loaded all that heavy the tank is not going to last too long. I understand the OP is going to be without power for several days at a time several times a year.

They might want to opt for a dual system such as about a 1 or 2 KW inverter type to run lights and a tv set and another larger one of around 5 or maybe

10 kw to power up the larger users such as the water heater for short periods of time.
Reply to
Ralph Mowery

Power requirements for any item are readily found:

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I've got my gasoline powered 5,500 watt generator hooked-up to run oil furnace, well, 2 freezers and refrigerator and a few lights and TV. Off line are water heater, stove, clothes drier and central air. Think it might take 5-10 gal gasoline to run all day, which I don't so I think a propane generator would take about the same. According to the calculator I referenced, I'm underpowered but have gotten away with it the many times I used it.

I know a guy hooked up to a gas line with a generator that runs his whole house which is quite large and kicks in when power fails. Set up like that probably runs 10 grand.

Reply to
Frank

around here home depot sell turn key natural gas backup generators pro inst alled with automatic transfer switch starting at about 5 grand. this is pre tty affordable, power fails the fault is detected, the generator starts, th e home is transfered to the generator till main power is restored...

this is key the switch over is automatic.

in the winter, if you happen to be out of town you could return to a frozen destroyed home.

auto switch over it requires nothing

if natural gas is available thats ideal..... gas is highly reliable. :)

propane is costly and the HOA may have issues with it.

the auto switch over generators are pretty quiet, hopefully HOA wouldnt blo ck it

buy a big enough generator to have some power for the neighbors

Reply to
bob haller

I was just going off what was given. The OP said they wanted to run their heat pump in the winter for heat and the in the summer for AC. Kitchen is electric, electric WH, it adds up. I'd rather have a 15KW that can do what's needed than a smaller one that can't. But they really need to add up the load. It's true that a bigger engine will use more fuel to some extent when running at lower loads than a smaller engine would. Just like a V8 car engine idling would compared to a 4 cylinder. But you have to size to the max load, not the lesser.

I just went outside to take a look at my AC. It's 5 ton, 14 SEER, minimum circuit ampacity is 36A. That's 8600W right there. I'm sure it's pulling substantially less once it gets going. But you need enough to start it and when starting it's going to be even higher that 8600W. The plate calls out a min breaker size of 45A, which gives you an idea of the starting reqts. How that compares to the heat pump, IDK, because we have no numbers for the actual heat pump. 5 ton AC is the largest AC, but when you're sizing for heat in the winter, I would think having a large heat pump in VA may not be that unusual either.

Cost of fuel, IDK. I've never heard anyone complain about the cost of nat gas. Propane though is a lot more expensive. It all comes down to what you want to do and how much you're willing to pay.

Reply to
trader_4

Propane or natural gas would only make sense if it was being used for more than just the generator as you pay for the NG service whether you use it or not, and you'll pay for the rental of the large propane tank too, whether you use any propane or not. Af dor the propane consumption of the generator, about 30% more propane than you would burn gasoline on a given generator, and count on derating the generator output by about the same amount. My 7000 watt gasoline generator puts out just over 5000 watts on either propane or Natural Gas. Mine is set up to run off natural gas, but I have a propane adapter (regulator and tank hoses) to allow it to run on Propane - and I can still run it on Gasoline as well.

Reply to
clare

Thanks everyone for all of the replies so far. I read them all. Here are some of my follow-up thoughts and ideas based on what I read:

The information about rough estimates of wattage needed for the heat pump, central A/C, etc. was very helpful. Trying to power them does seem to lean toward the idea that she would need about a 15 KW generator which would be expensive.

That information started me thinking that maybe she could get by with a much smaller generator system and not try to power the heat pump or central A/C during an outage -- in winter or in summer. Instead, maybe she could use the generator to power an electric room space heater or two. And, for A/C, maybe she could just buy a small one-room window A/C unit to get by during an outage.

The website that was suggested (

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) was very helpful to get an idea of the amount of wattage needed for various uses.

I was thinking that staying away from gasoline powered generators may be better for a number of reasons. One is the issue of storing the gasoline, whether it would stay stable if stored for a long time without being used, and whether trying to get a gasoline generator started when the power does go out may be an issue -- especially if it has been sitting around for half a year without being used. Another issue is that of refilling a hot generator safely, plus the question of being able to get to a gas station for more gas during a snowstorm -- and if the gas stations will have power to pump gas. So, that's why I was thinking of propane or natural gas instead of gasoline.

A manual cross-over or cut-over switch instead of an automatic switchover would work for her. She rarely travels, but if she were away during a power outage she could easily have one of her neighbors do the manual cross-over for the generator system.

Yes, there definitely is the question of what the HOA will allow. She would need to see if anyone else in her area has a backup generator system and what they have (if there are any, and if they are allowed by the HOA). One factor that she is apparently facing that many of the other homeowners within the HOA are not facing is the source of her electricity. She bought her home when the development was first being built, so she is in the "Phase

1" area. In her area, the power lines are run on poles and are subject to being knocked down by trees during storms. In the rest of the development, they went with underground electric power lines instead of lines up on poles. And, the power for those underground lines comes from a different power "grid"(?) or source than the power lines on the poles. So, the rest of her development rarely suffers any power outages. That may mean that few, if any, other homeowners in the HOA have or need backup generators.

Whether it is possible to get a natural gas hookup is another question. In my area, if the run is not too long, and if it means that the natural gas utility company will get a new residential customer for gas heat, maybe gas stove and oven, and gas hot water, they sometimes will run the pipe for free. Or, they may charge something like $1,000 to do the new hook-up. That's a lot of "ifs" but at least she could look into that. If she did get a natural gas connection, she may want to replace her electric heat pump with a natural gas heater anyway, and probably the electric stove/oven to gas, and the electric water heater to gas.

All of these things cost money, but if the choice is to spend money on some of these cost items (window A/C, gas heater, gas stove/oven, or whatever) versus coughing up money for a much larger backup generator system, opting for a smaller generator and buying gas appliances instead may be a better idea in the long run.

Reply to
TomR

Lots of good ideas, but guess the main thing is how much money does she want to spend, and how much money does she want to spend every time the poweris out for a week or whatever those long periods of time have been in the past. That is after that HOA. I live where I don't have to deal with that,so never think about a HOA.

Reply to
Ralph Mowery

Per Frank:

That's the quote I got when I looked into it.

Somebody I know had a whole-house gennie with auto-cutover and automagic self testing every so many weeks - fueled by a 500-gallon propane tank.

When our last significant outage hit (9 days for him), he discovered that the automagic self-testing had burned up the alternator and the thing was down hard for the entire outage. He got by on a portable.

Reply to
(PeteCresswell)

Wow, that had to be frustrating -- to have a big expensive "automatic" backup generator system in place, and then the one time that it is needed, it doesn't work.

Reply to
TomR

If you happen to ask, please get the brand of that unit, so we can consider a different brand.

Reply to
Stormin Mormon

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