# Solar power for an RV



## Saffron (May 24, 2006)

I really want to hook up solar power to my little RV for camping. When we stay at a campground, I would rather pay the cheap fees and not have power hookups and use solar power.

Has anyone ever done this before and could give me pointers?


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## wy_white_wolf (Oct 14, 2004)

Yes, I have a camp trailer on solar for power. Unless you are very frugal on your electricity usage you will never recover the costs of the system.

First thing you need to do is calculate how much power you plan on using. That is the wattage needs for everything and the number of hours you plan on using each device in a day. You need to consider worst case usage when calculating.

We would also need to know how often you plan on using it and how long each time.

Area that you are camping in would also be nice to know how much insolation is available.


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## Saffron (May 24, 2006)

I travel all over US in my RV when we use it (we are sporadic about it, sometimes a lot of travel weeks on the road, sometimes just a week here and there). Also camp at a resort a few miles up the road frequently with friends.
A lot of time spent in Southeast and eastern seaboard - but travel to Missouri, Wyoming, Colorado, Kansas, occasionally Texas.

I would prefer to use it instead of the generator. Especially right now as we are having issues with the generator shutting off and haven't found the cause yet.

Would like to use while driving to provide air conditioning in the hotter areas, or fans under normal use, have it run the frig, microwave, whatever instead of using gasoline and lp gas. Prefer to save those items.

I am not as concerned about recovering my costs as I am to getting used to using it, maintaining it, etc and having it for a SHTF situation or bugging out if it ever comes to that. That doesn't mean I don't want a frugal system though, because cost is an issue.

Tell me what information I need to get and I will.


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## Explorer (Dec 2, 2003)

Like frequently recommended here you need a "kill-a-watt" meter. Then measure every power consuming device along with the hours used each day. That will be a good start in sizing your potential system.


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## mightybooboo (Feb 10, 2004)

No A/C,start with about 600 watts.Still going to need propane for refer as the RV refer is a big energy hog,at least is on mine.

This would get you lights,limited microwave,laptop and satellite.When you see what you really want to use you can go from there.But from those Ive known,600 was a good start.

150 watts wont do squat really.Thats what ours has on roof,and it keeps the battery charged to start it after sitting,and a bit of lights,not much more when living in it.

If we were still RV'ing I'd really fill the roof.

Look for used panels around 2 dollars a watt on Craigslist,and blemished new panels at 2.73 watt and save some money if you care to.You dont have to go high dollar retail to set up an RV.

Panel prices are very very good right now BTW.


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## byexample (Aug 28, 2009)

Setting up an RV to run on solar is fairly straight forward. From a conceptual stand-point what you are looking to do is build an off-grid 12 volt solar power system and then you connect the batteries of that solar power system to the battery connectors of your RV.

That's the basic idea. There are many things that you can do to optimize your RV's electrical system for use with a solar power system. Here's some things we did to our RVs to make them work better on solar:

1). The wires in your RV's DC power system are likely under-sized. This doesn't matter so much for lighting and other low-power loads. But it creates some serious problems for electronically controlled appliances (fridge, furnace, etc..). We replaced the feed wires from the battery compartment to the DC power distribution panel with larger wires to keep voltage drop to a minimum. 

2). We also replaced the feed lines to the furnace with larger wires. Many folks will tell you that they can't run their RV's propane furnace on solar at night... the fan just keeps running and trying to ignite the propane... but it never actually kicks on and ultimately will suck your batteries dry without producing heat. This is caused by voltage drop due to under-sized wires. After upgrading our feed wires to our furnace we never had a problem running it on solar again... even in low power situations. I think we went with 4 gauge or 6 gauge copper wire for our furnace.

3). If you want to run an inverter and have AC power in your RV make sure you disconnect/disable the built-in AC to DC power converter or it will conflict with your solar power system... perhaps even causing damage. Also the 120 volt AC to 12 volt DC power supply / battery charger in most RVs is one of the most horrifically inefficient power supplies I've ever encountered. They are really, really bad news and should never be used in conjunction with a solar power system in my opinion.

4). If you want to use your RV's fridge you will have to use propane. The AC and DC power modes on those appliances simply convert electricity to heat to drive the cooling action in place of using propane. Any time you use electricity to create heat you are likely looking at a very inefficient conversion... and a lot of energy. If you try to run your propane fridge via electricity on a solar power system be prepared to run out of power quickly unless you have a really, really big system with lots of batteries.

5). Recommend that you avoid using your RV's built-in 25 watt incandescent lighting. We converted our RV lights over to 12 volt LED lights... which draw next to nothing compared to those little 25 watt bulbs. Those 25 watt bulbs will suck your batteries dry very quickly. You could also install 12 volt DC fluorescent lighting or, if you have an AC inverter, you can use regular household compact fluorescent lighting. Almost anything is better than an incandescent light... which is nothing more than a heating element that just happens to give off a little light.

Don't store / house flooded batteries inside your RV's living space. Regular lead/acid batteries out-gas hydrogen as a natural part of their operation and use. That type of battery must have very good ventilation. If you want / need to bring batteries inside your RV's living area look at the various types of sealed batteries that are rated for in-door use.

And as Explorer mentioned, make sure you have a means of measuring power draw. A kill-o-watt meter is great for measuring the power draw of AC appliances. For system-wide monitoring we use a Trimetric meter on our system(s)... recommend you consider some sort of system meter for any battery-based system. Going without a power meter is like driving a car without a gas gauge. Yeah, you can do it. But sooner or later your guestimates on how much gas/power you have will prove to be wrong.

Be well,

Patrick Harris
http://ByExample.com


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## Windy in Kansas (Jun 16, 2002)

I seem to recall reading some threads on this forum about solar applications and RV use. Good site even if there aren't.

http://www.rvnetwork.com/


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## mightybooboo (Feb 10, 2004)

delete,link didnt work

OK,lets see if this link works....Its a super rundown on making rv solar work

http://handybobsolar.wordpress.com/2009/07/22/solar-power-that-works/


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## ChristieAcres (Apr 11, 2009)

Would love to see more info on this Thread! We enjoy camping and go fairly often in the Winter, however, we happen to live in the Pacific Northwest. Sun exposure isn't the best, but there are areas where we go that get better rays... Currently? This may crack up you guys...

My DH has an Inverter he wired under the hood of our Diesel ol' work-truck (2 heavy duty deep batteries...close enough, right?). Okay, while traveling, he charges up these batteries and also the Trailer battery. When we camp, he flips the power over to the truck batteries. In the morning, he switches the power back to the Trailer battery, and we take the truck for a drive. In case the truck batteries are too low for the truck to start, we have a great little 1,000 watt generator (which is then used to charge the truck batteries up). There should be a better way...

Why doesn't someone invent a wind operated system for RV's... While driving down the road, the velocity (like a windmill) creates the power needed to be converted via an inverter (probably more than that) to charge battery banks. Don't ask. I already asked my DH last year, why we couldn't get a series of batteries and have the vehicle system charge them in succession. Yes, I got a blank look and later the "Lori, that won't work because..."

Where we live, we don't get enough sun exposure to make solar panels feasible at all. I figure if we go Solar and go Wind, too? We got it covered (nice windstorms over the Winter and enough wind to fill in the gaps when the sun isn't shining...). In the meantime, DH designed and built us a woodstove and is about to put in a steam system using it, also, to bring more heat back to our bedroom (other end of our home). We already use the blower from the furnace to act as the heatilator (DH designed it to blow through steel tubes and right out the other side of the woodstove). Just above this hot air flow, which rises, of course, there is a steel clothing rack (another DH design) suspended from the ceiling. No, we don't use the clothes dryer... For the rest of the year, I have a clothesline... Now, if we could just get this electricity challenge figured out... DH thinks it is too cost prohibitive to put in both wind/solar systems... With Solar prices down, and everything else down... Thoughts?

Wood? Our property has life-long supply, easily.


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## Micahn (Nov 19, 2005)

My dad retired last year and got himself a new motor home. In the last couple of months he has added Solar to it. He can run everything but the AC on solar full time if needed.
In a few months he is planning on going almost full time RV living so he wanted it set up to save as much $$$ as possible. 
He has I believe 2 panels on the roof (Not sure of the size off hand) and had added 4 6V batteries for storage. 

He has also added many other options as air bags, one of them banks systems on the engine, as well as many other new toys. He even has a wireless network set up with a version Internet card plus a wireless printer.

Oh and he has talking about getting a wind generator for when parks some place for a while.


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## solidwoods (Dec 23, 2005)

I like the generator idea.
Solar panels are $$ per watt.
You can build your own gen with a small gas engine and a car alternator.
You can use a flexible coupling instead of pulleys and belt (see Motion industries for these)
Build it in a metal frame so its portable, use a large muffler for noise.
Solar just doesn't make a whole lot of elec and for a part time use item it's more expensive (because of little purchase cost payback).
Even the purchase of a 110vac gen could be justified for dual use to use if your home elec it out.
jim


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