On Sun, 6 Oct 2019 15:31:32 -0400, Ralph Mowery
wrote:

In article , lid says...
have a propane generator and it is not going to run very long on a
15 pound tank (AKA 20 but never true). My 5.5 KW burns 0.8 gallons an
hour. A "grille" tank would last a little over 4 hours.

I had one filled, and weighed it. 36.6 pounds - the tare weight (16.6) =
20 pounds of propane. Another tank held only 19 pounds, still a lot more
than the 15 you get at exchange places.



I have heard the exchange places like Blue Rhino only put about 15
pounds in the 20 pound tanks. I go to Tractor supply and they claim to
weight the propane and charge by the ammount.

My generator is rated for about 3500 watts on gas and 3000 on propane.
The 4 gallon tank claims 10 hours on gas and 9 hours on a 20 pound tank
of propane at 1/2 load.

I do have a 5 kw gas unit that I have had for about 15 years, but have
not used it long enough to know how long it will run. I bought the
smaller unit because of dual fuel and a lower power unit will usually
run longer on the same ammount of fuel if it is not loaded very heavy.
All so with the propane if the power is only out for a couple of hours I
do not have to fool with the gasoline and the storage problems.

I have a 120 gallon tank buried in the yard. That is good for about 6
days. (24/7 at pretty much full load)
I do not see any drop in output on propane either. Maybe the engine on
mine is just oversized for the generator head or something. The
difference shows up in fuel consumption. 0.5 GPH gasoline vs 0.8 GPM
on propane. This is based on an 8 day outage where I was running half
gasoline and half time on propane so I got a pretty good test.