Portable Gas Generator Question archived

We have a gas line that now runs outside the house to our grill.

Would it be advisable to buy a portable gas generator and hook it up there in case of a power outage? It seems like a relatively affordable solution to emergency preparedness and I'm interested in peoples' thoughts.

Also very curious about this, as we have a recently upgraded line with shutoff valve. Will be doing more research sometime after we finally get power back!

Please do!

Another question. The nat gas generators I've looked at also seem to be able to take gasoline. Is that correct?

Someone mentioned trifuel generators on another thread.

First it would have to be a natural gas generator.

Second, I don't think that will work - the volume of gas needed to run a generator is much much higher than a grill.

But I imagine that if a high volume line were run to the grill, with a line for a generator, then it would work for both

peteglider said:

Second, I don't think that will work - the volume of gas needed to run a generator is much much higher than a grill.

I think they are talking about portable nat gas generators and not whole house generators and they have ones that run off of propane tanks so why shouldn't a 'grill' gas line provide enough fuel?

http://www.electricgeneratorsdirect.com/Winco-HPS6000HE-Portable-Generator/p1176.html

Interested in a tri-fuel generator. NG spec 160ft/ hr. I have a half inch line off my main manifold to the backporch for a gas grill. Should that provide adequate flow?

by David Distel from Minnesota on September 16, 2012

A: Length of Fuel Line* -Fuel Line Size

Less than 25 feet -3/4 inch black pipe
25 to 100 feet -1 inch black pipe
Over 100 feet -not recommended**


Of course I have no idea if the line to the grill is 3/4 inch or not.

About multi fuel generator -- what ever their wattage, they'd be lower by 20 - 30% using natural gas.

My natural gas grill line, at least the part above ground, seems to be some sort of flexible copper tubing, that's really quite small. It was here when I bought the house, don't know if there is 1/2" or 3/4" coming out of the house to the grill, but perhaps. From what I see on my grill, I can't imagine it would provide enough volume.

The generator linked to above -- NG Fuel Consumption=160 ft³/hr -- I don't know how that works with NG pressure in the house vs pipe size -- I linked to an online calculator below, but for a Friday afternoon, I'm too braindead to figure it out.

But as I noted, no reason you couldn't run 3/4" or even 1" to the grill (other than cost and ability of the internal house gas plumbing to supply adequate volume).

Next time I have a plumber to the house (and there' always a next time ha!), I'll have him look at the lines in the basement to learn more.

NG GAS ONLINE CALCULATOR --
http://www.engineeringtoolbox.com/natural-gas-pipe-calculator-d_1042.html

I have a 4000 watt(peak) propane powered generator, and would think propane and nat gas burn pretty similarly. They definitely use quite a bit more fuel than a grill. Mine will go about 10 hours on one 20 lb tank of propane (keep in mind this is a 4000 watt so the more wattage you use the more fuel it uses). Also, nat gas generators are considerably more expensive and the ones i've seen seem to be very serious permanent install type. I did have a neighbor tell me about a company up in Maine that will sell you a generator and modify it to take natural gas for you. Not sure what they were called but I can ask him...

peteglider said:

First it would have to be a natural gas generator.

Second, I don't think that will work - the volume of gas needed to run a generator is much much higher than a grill.

But I imagine that if a high volume line were run to the grill, with a line for a generator, then it would work for both

The line was specifically put in to be big enough for a grill or a generator. So that's taken care of.

I guess my question is more whether a portable natural gas generator makes sense as a backup power solution. W/R/T heat, I was also think I could run a space heater off of it, and maybe put in a wood burning stove in a separate area.

I really just want to make emergency preparations that are not going to kill me cost wise.

There are several companies that make conversion kits to turn gas generators into NG or propane systems. Sometimes it is a bolt-on, sometimes you need to drill the carb... always (of course) the warranty is voided on the generator, but that's not always a terrible thing.

What I've been running into is the problem alluded to above - diameter of gas pipe and the length of the run to the generator. While I can pay a plumber to upgrade my line, well... I may just stick it out with gasoline for the forseeable future.

Oh, and I think someone already mentioned that you can buy tri-fuel generators - tempting but expensive. Then again, not having to deal with gasoline is pretty appealing.

I guess it'll take a bit of research to come up with the right answer. At the moment, if I hadn't got an investment in a gas generator already... I'd probably go trifuel and pay a plumber to upgrade my gas line.

ALee said:

peteglider said:

First it would have to be a natural gas generator.

Second, I don't think that will work - the volume of gas needed to run a generator is much much higher than a grill.

But I imagine that if a high volume line were run to the grill, with a line for a generator, then it would work for both

The line was specifically put in to be big enough for a grill or a generator. So that's taken care of.

I guess my question is more whether a portable natural gas generator makes sense as a backup power solution. W/R/T heat, I was also think I could run a space heater off of it, and maybe put in a wood burning stove in a separate area.

I really just want to make emergency preparations that are not going to kill me cost wise.

Hell, if you are sure your gas line is up to it... then this could be VERY cost effective and relatively simple!

I'd suggest a 7000 watt system, get an electrician to wire it into your panel (people use transfer panels, but I prefer the interlock kit (www.interlockkit.com) and you're probably in business! For me the tough part is (a) the gas line and (b) the sunk cost of my gasoline generator... two problems you don't have!

Sure you can do it and it will work - however it depends on how big of a generator you need to feed (Watt & HP). We hashed out a lot of this on another thread. I contributed the following info: http://www.propane-generators.com/natural-gas.htm

(The chart gives a good guidance at least for this suppliers kits (converting gas and propane generators to NG) of required Pipe size (inches) Based on Distance in feet from Meter relative to Generator Wattage & Engine HP). For example if you converted your 4000W (8HP or less) gas generator to NG with their kit, you can run it from your home NG with a 1/2" pipe no further than 30' from the meter. If you want it 50' or 100' from the meter, you gotta up your pipe to 3/4", and so on. Yes you lose a bit of power w/a conversion but it will work, and you can always buy a trifuel generator and just go with the NG. But apparently even if you had a good sized generator of 8000W & 16HP, a 1" pipe will cover you whether you want to have it 50' or 100' from the meter. Again, I am offering that link as general guidance of what I can imagine you can expect across the line with all generators out there.

The real point is you can certainly do it.

Damn you, Mapledrew! I now feel obligated to do this. Curses!

Family friends, when I was a boy, had a house on a lake in Maine that was so remote there was no electricity. Propane was used for the stove, oven, hot water, fridge, and lighting inside and out. In the winter when the lake froze over, propane deliveries would be made (ice truckers!).

So NG could be a back up in many ways. Actually as a space heater, it's also very efficient.

Thank you for the comments!

Now, does anyone have a recommendation for a portable gas generator? And was there a thread somewhere else with how to calculate how big a generator you need?

My primary recommendation is to NOT run out today and buy one! Meaning, take a little time, do some research and make a good purchase.

Manufacturers I like

Honda
Briggs and Stratton
Honeywell (I believe the new ones use generac engines)
Generac


There are a few links/threads on MOL that talk about sizing a generator; here's one from google:

http://www.donrowe.com/inverters/usage_chart.html


Note the difference between "starting" and "running". This is why the generator you buy needs to be reasonably well sized (and make sure your generator is clearly described... 6000 watt generator should be 6000 running, with a surge of 7000 or more).


There are plenty of threads right now on storing gas safely, how much you might need, etc. Without knowing your situation or your requirements, I would not suggest anything less than 6000 watts and would be comfortable suggesting 7500 to you. My reasoning is that the units aren't THAT much more expensive, you may find yourself in a position to want to extend power to your immediate neighbors, and you know... why buy it twice? No real harm to buying a larger than needed generator, but a true pain in the ass to buy one a little too small.

I run my 7500 at a very low percentage of total output and the gas efficiency is great. If I need to draw significantly more power (i.e. rainstorm with all pumps going, neighbors pumps going, etc) then I have that capacity.

Also, and I"m sorry that this has been repeated (by me!) already... but having some real extension cords in the house is a good idea:

http://www.amazon.com/Coleman-Cable-Outdoor-Extension-Lighted/dp/B000A3I3GA/ref=sr_1_1?ie=UTF8&qid=1352552569&sr=8-1&keywords=extension+cord+10+gauge

Even if you consult with an electrician and do a panel hookup, get yourself a few of these babies. You can go 12 gauge if you want to save a bit of money, but don't go lower please!


http://www.amazon.com/Coleman-Cable-50-Foot-Multi-Outlet-Extension/dp/B0004UKZD8/ref=sr_1_10?ie=UTF8&qid=1352552668&sr=8-10&keywords=extension+cord+12%2F3



Depending on your panel you may be able to go with an Interlock kit; great system, foolproof, code compliant and just really really functional! Your electrician will be able to help you, or I can give you the name and number of my guy.

www.interlockkit.com

If you are just running fridge/lights/gas boiler/tv a 4000 peak watt should be fine. If you need to run a sump pump or forced air heater it gets a bit more complicated. I read somewhere that the optimal usage load of a gennie is around 60-70 percent. Any less and you are wasting gas, any more and you are stressing the generator. Kind of like how a car is most efficient at 50mph I guess.

Probably true - but "perfect" sizing of a generator is pretty hard to do... and when you consider the neighbors (even if they have a generator, it might fail... or yours might!) it has always made sense to me to buy larger than the minimum required.

Guy at work did the nat gas conversion. It's been done for decades. He's run his for hundreds of hours, both to test (that's the kind of guy he is) and now in Sandy.

I was skeptical but am sold. From what he has said and wha I've read there is no appreciable drop off in output.

Edit for clarity- people have done it for decades. His is fairly new. As far as voiding warranty, if you use one that drills the carb, yeah that'll void it.

My system is out of warranty already (because it's three years old) so that wouldn't really be an issue for me. If the darn thing will run well on NG, I am very (very) interested in doing the conversion.

I guess I need to start researching conversion kits... and have a chat with my plumber about running that gas line.

Whatever I figure out ill share. You do the same!

The thing is... and now I have sympathy for my neighbors who don't own generators yet.... is that I JUST DON'T WANT TO DO ANYTHING ELSE. I want to watch television, maybe rake the yard, take a nap... not think about an NG conversion for my generator.

Having gotten that out of the way, I am on it! I found a few websites that sell kits, but my generator/engine isn't on it (though I suspect I have a US made "knockoff" Honda 420 on this Honeywell). What I really want is a simple and easy way to set up for NG, but be able to convert back to gasoline power in about 30 minutes or less - assuming a gas line break, some other kind of "isolating" disaster.

I promise I'll get back to the thread in a week or two with what I find out. My real (financial) worry is the gas line.

From what I understand you just need them to run it to the side of your house like an outdoor faucet. You can tree it off whatever gas is in the basement to a wall (dryer?). Then you use a quick connect hose when you need it for the generator or a grill.

I don't think it'll be that bad. I'm working parallel to you. Will let you know what my quotes are.

There is this company that sells a conversion kit that covers all 3 fuel types. No drilling of carb jets. The C kit is about $179.00. Seems to be a fairly easy install. Check them out at uscarb.com or Google them. Also, there are a few you tube videos showing how to do the conversion.

Thanks! I like "easy install", and if I can back it out and go back to gas easily that's a huge bonus.

Those Yamaha tri-fuel generators look like a great idea. Expensive at $3700 for 6k watts but if you simply run a natural gas line to the outside of your house and put in an external generator inlet box in the same place along with an interlock or transfer switch you have a REALLY nice solution that is quiet, doesn't need gasoline, uses what is now a low-cost fuel source in natural gas and you can roll the generator away when not in use.

I'm tempted to suggest buying two gas generators and converting one - then you have some redundancy AND you've saved money at the same time.

You can buy mine. It's got roughly 10 hours on it. I'm going to check out the Yamaha.

I'll buy yours (maybe). What is it?