What size Solar Panel?

[BIG BOB]

I just purchased a 1994 28' Fleetwood Savanna travel trailer. I also installed 2-6v Trojan T105 batteries in series. The trailer has a hookup for a solar panel. I live in the Pacific Northwest next to Spokane, Washington. What size panel would I need to meet the demands of this trailer and area?

 

[illflem]

Bob, it depends entirely on how much power you use. The best bang for the buck is used Arco panels, thousands of them came off a very large solar farm that was dismantled years ago. They are about 16"x40" and in excellent condition. One thing great about solar panels is that they never wear out unless damaged, used is great. There are a couple of places in Spokane that sell panels that can hook you up. I bought some from an outfit in Sandpoint, http://www.backwoodssolar.com/ , great folks to work with, they will set you up exactly to your needs.

 

[jandtjil]

Solar panels

Big Bob

From the Mr Solar website (www.mrsolar.com), try the following link. http://www.mrsolar.com/faq/faq5.htm



JJ

 

[JWhitcomb]

Output

Illfem, do you you know the out put of those Arco panels, wats and amps?

 

[illflem]

JW, the Arco's were 22 watts @ 17 volts when new in 1980, they typically lose about 10% with age, so about 20 watts. I looked around a little for used Arcos after posting earlier, didn't find any. I know there must still be some out there though, the dismantled solar farm most came from wasn't just acres, it was square miles in the Mojave desert. Environmentalists didn't like it, too much shade for the lizards. Just need to look harder, I paid $90 each for mine. A new one with the same output will set you back about $500, makes you want to consider a generator instead.



I used seven of the Arcos to run remote electrical irrigation system valves, one panel each. Had to run them thru an inverter to get 110 AC then kick it back down to 24 volts, all just to get AC. Also needed a $12 regulator at each station. The single $40 Napa deep cycle battery at each station has lasted ten years with just adding water. I've been very pleased how trouble free the systems have been, just water once a year. Batteries like solar power.

 

[JWhitcomb]

Illflem, the reason I was asking is I have some of those and have lost any info on them. At 20 watts that would be around 3 amps I think. I will have to look up the data to convert. Thanks

 

[illflem]

20w/17v = 1. 176 amps

 

[dabubba]

Big bob--Another tdr member and I are in the solar bus---Your panel size will depend on how you use your rig-- if you are just wanting to charge the battery from running your lights and heater on a weekend get away, a 50-75 watt panel will be enough- maybe a tv, but you need to be conservative on your power-- I have a mid size system with a 100 & 75 watt panel and 6 trog 6V batts to a 1. 5 kw inverter and have had no complaints on batterys- My partner has a 5kw inverter with 4 6V trog batts and has no complaints but he made that a separate system in his rv for ac only-- he can run his ac for awhile on solar--- if you have any questions or would like some personalized help email me- or call me 1-866-sun-wind, I'm in after 4:00

pm pst mention the tdr and I'll try my best to meet or beat other's prices on solar or wind pv systems or parts-

 

[klenger]

I have two 120 watt solar panels on my 5er. Works great. With a small panel and two T105 batteries, the batteries will be fully charged after a few days on not being used, and you may get about 2 days of use out of the batteries, but the panel will not do much to maintain the charge. If you want coutinuous power from solar panels for extended periods of time (severl days or more) you need to calculate your amp-hours of use per day, and then calculate how many watts of panels you need. Rembermbe that the output power of the panels in measured with direct sun perpendicular to the panel. This does not happen in the real world. I guess that I spend about $1500 for the two solar panels and controller, but for me the price was well worth it. During the summer, when the weather is mild and we do not run the furnace much, the panels will keep the batteries charged indefinitly. We run the stereo a good part of the day, lights for several hours at night, a laptop computer for a hour of so, and the water pump. Off season with less sunlight and more demand from lights and furnace, the pannels cannot keep up with demand.



Clear as mud?



kl

 

[RobG]

I have a pair of Kyocera 120 watt panels on my Lance 1030 truck camper, and a 16A charge controller. I've been running a pair of cheap Costco-brand Group 27 batteries, but they're about dead, so I'm going to step up to a pair of Trojan Group 31's. I really want to go to three of 'em, so I may very well get three, since I'm going to rewire things anyway...



Anyway... the key is to have lots of panels and lots of batteries. The goal is to keep from draining your batteries below half, keep 'em full of water (which is what I failed to do on the Costco batteries and why they're dead) and they'll last well.



I strongly recommend the little $12 book from the folks at RV Solar Electric (www.rvsolarelectric.com). It'll tell you everything you ever wanted to know about batteries and solar power.



Rob

 

[BIG BOB]

That's a great site!

Thanks Rob,



That site is great. I'll give Noel a call for his recommendations.



Thank every for the great information.