Posted by Frontier on December 24, 2010, 10:20 pm
I would say it comes down to how often are you without power and rely on the
generator. If itís an infrequent occasion that you run this generator I
would say itís a waste of time. We are 100% off grid and avoid genset power
like the plague. If you think AE (solar/wind) is expensive per watt hour,
genset power is ridiculous. There are all kinds of other issues as well.
Batteries donít like to see only hard, high amperage, charging. If your
getting them on the cheap/free thatís one thing.
I have often though a nice hybrid setup would be one that combines many of
the concepts in this thread, multiple backups (main batteries, backed up by
UPS, etc.), perhaps two gensets, one small to run the core items,
fridge/freezer, lighting, TV, perhaps furnace fan, well pump, etc. the core
essentials. Then a larger genset that would charge batteries AND run the
core items when it is running. One genset running at a time of course. As I
mention, in a power outage the vast majority of time a miniscule amount of
the generators fuel consumption is being used to power items in your home.
The rest of the fuel dollars are flying out the exhaust in idle waste.
Posted by Bruce Gordon on December 13, 2010, 7:08 pm
Bring your question over to the Onan Forum on www.smokstak.com and one
of our Resident Smartguys, can give you ALL the Answers to ANY of your
Onan Questions. They have hundreds of ManYears of professional Onan
Bruce in Alaska add path before the @ for email
Posted by Curbie on December 25, 2010, 12:54 am
On Mon, 13 Dec 2010 10:09:27 -0800, Carla Fong
The general formula for fuel consumption (at 100% load) is:
So the Honda GX 650 is about 23 HP.
1 Horse Power = 2545 btu/h.
The Fuel Heat-Value of Natural Gas is 1030 btu/ft^3.
Modern small spark ignition engines are about 30% efficient.
So, (((23*2545)/1030)*(1/0.3)) = 189.43ft^3
Where Onan puts fuel consumption at 184 ft^3
This general formula for fuel consumption will get you pretty close
for any internal combustion engine at 100% load.