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+--- Thread: Propane generator for off grid solar system (/showthread.php?tid=8681)
Propane generator for off grid solar system - hotinhawaii - 03-31-2011
Does anyone have a recommendation for a propane generator and installer? I am building a house that will have a 7.2kw PV system with 15 panels and 16 batteries. It has to be propane, so don't even suggest other options, please. I was quoted $22,000 for a 25 kw Onan gen but it just seems huge as a backup! And, it's too expensive. I would like it to automatically go on when batteries are low. The electronics are all Outback.
RE: Propane generator for off grid solar system - Radiopeg - 03-31-2011
My other half says try Generac, he has seen them here on the mainland at Home Depot. He also said many people "convert" another type over to propane. Don't have any specifics on that process, but hope the thought helps. Peggy
RE: Propane generator for off grid solar system - hotinhawaii - 03-31-2011
Rob, sorry I posted this in the wrong place. Move it if you'd like.
RE: Propane generator for off grid solar system - peteadams - 03-31-2011
I've commented on this before (http://www.punaweb.org/Forum/topic.asp?TOPIC_ID=8380&whichpage=6), but the main purpose of batteries, in my opinion, in a residential PV installation is to get you through the night and, secondly, to cushion very gray days. The purpose of the generator is to feed the batteries at night, handle very gray days and occasional heavy loads. If you commonly need to run a generator during the day the solar panel installation is inadequate for your power draw or you designed it that way. Usually a money versus life style issue.
That said, a 25kw generator seems huge overkill unless you are planning large power draws (a/c, big refrigerator) and you are looking at the solar panels only as supplement. Your system is almost 3x our 2.6kw system (3-3.5kw typical daily draw), but I can easily charge our eight L-16 batteries with our 3kw Honda in a few hours in the evening even though we are watching TV and only on battery power. Our original set of twelve batteries was also easily charged by a 6500 contractor style generator. The generator previous to the Honda was a 6.5kw Chinese propane machine, about $1000. Propane was selected for one major reason. Since we only used the generator occasionally the fuel never got stale or collected moisture. A plus was that the machine was much cleaner to operate and maintain than a gas or diesel. The portability of the Honda turned out to be very useful for us at the nursery and it's being used for a lot more than charging batteries now.
White Cloud Nursery
www.whitecloudnursery.com
"If you think education is expensive, wait until you see how much stupid costs"
RE: Propane generator for off grid solar system - Kapohocat - 03-31-2011
I would say the big generator is good - Robert put one in for K&N - they whined at the size but it takes about 1/4 the time to charge the batteries as the smaller honda. So they save a lot in fuel costs and have more than double recovered the cost in 9 years and it is 20 yr 100% duty rated. Also a lot less time to listen to genny hum.
They got a Kubota Marine diesel for $6000 - they are now going for about $9000. I dont know what the propane genny's are going for.
RE: Propane generator for off grid solar system - hrooster - 03-31-2011
Generac specifically VOIDS the warranty if it is used as backup for solar
http://the-hroost.com
RE: Propane generator for off grid solar system - David M - 03-31-2011
Curious about your 480 watt panels. Could you tell me more about them?
Can't think of the name, but there is a generator place in Shipman and they can build you a propane generator, one of my neighbors has one. As for size, I was advised that generator should be 2x inverter capability, butI don't have a good refence for that. We have a 25kw diesel for our 4.5kw PVs and it does a great job.
David
Ninole Resident
RE: Propane generator for off grid solar system - Sniper Steve - 04-01-2011
I'm posting a link for you to check out. I've bought gensets from this company in the past and have always been happy with everything. You always want more power then you need. You never want to max out your genset. Here is a link for a honda and allot cheaper. If your looking for a totally closed unit. Hit the home button and research the LP generators. I've personally ran dual 100K units on ocean going tugs. I know about having power all the time and run generators. Hit me up if you need any help. These guys should be able to also set you up with a timer or transfer switch to charge your system. Don't know much about charging all those batteries, but these guys are very nice and should be able to help you out.
Good luck,
Steve
http://www.generatorsales.com/order/Honda-13kw-Propane-Generator.asp?page=H04595