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APevtPV · 01-05-2016, 09:44 AM

I'm wanting to make my 1973 31' a/s Excella fully solar. right now it has the original gas/electric fridge, gas oven and range, and the regular electricity. The heater runs off of propane and we have the A/C (although I'd rather not run it). I plan to have a TV in there and small appliances (but not all plugged in at once, of course).

I'm just trying to figure out how many solar panels/amps I'll need to get to be sustainable.

Has anyone made their airstream fully solar? I saw some people online who put five 500 watt flexible solar panels on their Fleetwood Excursion RV.. I feel like that would draw more power than the airstream for some reason, but I may be wrong. Here's the link to the page I saw the info (Powerful and Flexible RV Solar Panels)

Any ideas/thoughts?

Trailbob · 01-06-2016, 10:06 AM

You might search the Generator and Solar forum for info, and post your questions there. Lots of knowledgeable and helpful folks. Also check out AM Solar and their tutorial.

Generators & Solar Power - Airstream Forums

dznf0g · 01-06-2016, 10:35 AM

For my needs, I have settled in at 260 watts. A 100 watt panel permanently mounted rooftop and a 160 watt portable unit, as I camp in the shade mostly.

KJRitchie · 01-06-2016, 10:39 AM

I guess it all comes down to your power needs and your budget. You need to calculate what is your typical daily power draw will be and then plan for the appropriate battery capacity to cover that need. Then you can determine the amount of solar that is needed to charge the batteries on a daily basis. The costs will add up fast.

Kelvin

dznf0g · 01-06-2016, 10:49 AM

We typically use 28 - 30 Ah per day. That's with LED lighting, water pump, charge a phone or two, fridge, and water heater on propane, a bit of music, and not much LED TV.

Gearheart · 01-06-2016, 02:59 PM

Quote:

Originally Posted by dznf0g

We typically use 28 - 30 Ah per day. That's with LED lighting, water pump, charge a phone or two, fridge, and water heater on propane, a bit of music, and not much LED TV.

Amps X volts = watts so it is important to know if that is 30 AH @ 12 V or 30 AH @ 120 V. The 12 volt scenario is 360 watt hours so a 40 watt unit with 9 hours of sun has you covered. 120 volts is 10 X more.

Sbb · 01-06-2016, 03:05 PM

Isn't the amount of Solar watts only as good as how many batteries you have to take in the power? More watts, more batteries needed? Could be totally wrong here. I have one panel I put out, portable style since I find the shade is a huge help in an Airstream, and I have two deep cycle batteries. Any more solar and I would have to get different batteries. It suits my needs, but my needs are small.

KJRitchie · 01-06-2016, 03:15 PM

More solar means more amps so if you have 600 watts of solar and only 200ah battery bank the panels will charge the batteries faster than if you only had a 200w solar. 200w puts out about 11amps so 600watts would put out over 30amps. Also helps on cloudy days. The solar charge controller also has to have the correct charging characteristics to match the battery type; flooded, AGM, Lithium.

I'm thinking the solar system that would work for me is 200 watts on the roof and 200 watts of portable solar. I'd have this matched to a 200ah battery system. Our energy needs are basic too.

The roof panels could charge the batteries while towing. When at a campsite we could park in the shade and use portable or if in the sun would have 400w of solar if deploying the portable.

Kelvin

Silver Hawk · 01-06-2016, 04:14 PM

I have a 200 watt solar panel on my roof, 300amps of 2x 6volt AGM batteries.
In two years of traveling twice a year (spring and fall - don't like the crowds in summer), I've never used the 2000i Honda I bought (I take it just in case).
We boondock mostly. The batteries never get below 50% when we camp and are charged up by noon when we travel (both solar and TV).
We run an inverter for microwave, tv and coffee grinder - all else is 12volt. We don't 'watch' our electrical use. I just watch our battery level and haven't had a problem yet.
This may help you with real world use verses calculated use.

KJRitchie · 01-06-2016, 04:35 PM

What brand and model of battery are you using? What solar controller, inverter/charger?

Kelvin

dznf0g · 01-06-2016, 05:40 PM

Quote:

Originally Posted by Gearheart

Amps X volts = watts so it is important to know if that is 30 AH @ 12 V or 30 AH @ 120 V. The 12 volt scenario is 360 watt hours so a 40 watt unit with 9 hours of sun has you covered. 120 volts is 10 X more.

That's 12 v. But....at my latitude, count on 7 hours a day and 5 hours at anything close to maximizing the panels. Add to that cloudy 0r partly cloudy days, and 40 watts is woefully inadequate.

airdreamers · 01-06-2016, 05:42 PM

I am not very knowledgeable when it comes to sola, but think for my needs 2-150 watt panels with a Solar Boost Controller serves me well. Run everything moderately but the A/C. n Full battery charge most sunny days by noon. Battery storage is two #27 group.

lewster · 01-06-2016, 05:48 PM

Quote:

Originally Posted by APevtPV

I'm wanting to make my 1973 31' a/s Excella fully solar. right now it has the original gas/electric fridge, gas oven and range, and the regular electricity. The heater runs off of propane and we have the A/C (although I'd rather not run it). I plan to have a TV in there and small appliances (but not all plugged in at once, of course).

I'm just trying to figure out how many solar panels/amps I'll need to get to be sustainable.

Has anyone made their airstream fully solar? I saw some people online who put five 500 watt flexible solar panels on their Fleetwood Excursion RV.. I feel like that would draw more power than the airstream for some reason, but I may be wrong. Here's the link to the page I saw the info (Powerful and Flexible RV Solar Panels)

Any ideas/thoughts?

Just a few comments from one who installs RV solar for a living:

The Winns were sponsored by Go-Power, the company that sells the supposedly wonderful flex panels. THEY ARE NOT THAT POWERFUL when compared to solid 100 watt monocrystaline panels. I have written several times about my personal experience with flex panels in direct comparison to hard panels. AM Solar was selling them last year when all of the hype about them hit the market. They soon realized that their output was a fraction of what it could be using hard panels and discontinued them after discovering other problems from their design and construction.

The rat's nest of connectors on their roof is also a definite source for voltage drop (an unwanted side effect that will decrease the efficiency of your solar array) from these panels, making them far more inefficient than they already are.

Start your solar education here: AM Solar's Educational Pages for RV Solar Systems

There are many ways to cobble together a system that will 'work' from available solar components. There are only a few reliable sources that have been in the RV solar business for a long time that can design a system for you using fully compatible, proven components that will provide you with the maximum output and return for your investment dollars.

Choose wisely!!!!

Smari · 01-07-2016, 10:24 AM

Quote:

Originally Posted by KJRitchie

I guess it all comes down to your power needs and your budget. You need to calculate what is your typical daily power draw will be and then plan for the appropriate battery capacity to cover that need. Then you can determine the amount of solar that is needed to charge the batteries on a daily basis. The costs will add up fast.

Kelvin

How does one calculate or measure power needs? I'm thinking of solar down the road a bit, and would love to actually measure on a daily basis, what I use until then. Is that possible?

lewster · 01-07-2016, 10:33 AM

Do some reading from the link in post 13.

Lew Farber
RVIA/RVDA Nationally Certified Master Tech
ABYC Certified Master Marine Electrician
Master Tech Energy Systems, Inc.
AM Solar Certified Installation Center*AMS Lithium Batteries
Lifeline AGM Batteries**Magnum Inverters
541-490-6357

switz · 01-07-2016, 12:24 PM

More than the minimal number of panels means the batteries get charged quicker when clouds interrupt the sunshine during the day.

Clipper2014 · 01-07-2016, 12:33 PM

You will never be able to really run AC off of any conceivable installation of panels and batteries on your trailer, or other high draw devices. From experience the best bet is a portable 140-160 watt solar panel that you can move a couple of times a day to get it in the sun and a couple of good house batteries. You start out fully charged, you use up 30-40 amps a day, you get an "average" of 30 solar amps a day, you run an "average" deficit of 5- amps per day for a week of boon docking. You'll be OK.

The above arrangement will cost you less than $500, and the work to move the panels around. $500 might be less than what it would cost you just for labor to mount panels and install a solar charging system in your trailer.

On really sunny days when you can keep your panels exposed to the direct sun for 6 plus hours a day, you will run a surplus, on crummy days a deficit. Rather than running the furnace all the time, wear a sweater. Read or play games rather than watching TV. You'll be OK.

If you want to go really crazy you could get a second panel of the same size, about $350, assuming the charge controller you bought for the first panel can handle the load. You wire them together, but now it's a more time consuming or a two man job to move and store them. They only weigh about 25 pounds, but with all the wiring it is more complicated. With this extra panel you will now pick up a lot more amps. Use the micro wave with an inverter a little to reheat your coffee or maybe even prepare your TV dinners. Use your hair dryer for a few minutes. Fat City!

More direct and productive of a lot more amps is a generator. One small, quiet, economical Honda generator will easily keep your battery's topped up if you limit your amp draw. You would probably need to run it 1-2 hr.s per day. The solar panels don't need to be run, just moved to produce quiet power See how your neighbors like it?
A couple of big, snarling Honda generators can be run together with your AC, the noise of each canceling out the noise of the other and viola! AC.
These kinds of generators, however, have a weigh penalty (80b.s each) for you to manage and store, and require you maintain a good supply of gas on hand to feed them.

Cheers

interstateflyer · 01-07-2016, 12:53 PM

AM Solar at Welcome to AM Solar_Your RV Solar Specialists since 1987 is a great resource. They sell kits for DYI and can also recommend installers around the country that use their product.

They installed 325 watts plus two Lifeline 6V AGM batteries on our 23D. We can go out almost indefinitely with this setup. We could have gone with 200 watts but wanted a quicker recovery time for the batteries.

mandolindave · 01-07-2016, 01:23 PM

Well…How big is the glass, and how thirsty are you ?

wcrockett · 01-07-2016, 01:24 PM

Look at the power consumption for each appliance in the trailer to estimate how many amps you will use per day. The labels on the appliances usually show power in watts and current in amps. You need batterys that provide at least more than twice the amps consumed per day. So if you use 75 amps per day you need more than 150 amps of battery capacity per day. If you have 300 amos then theoretically you should be able to go 2 days without charging the batteries. As a rule of thumb you need 100 watts of solar for every 100 amp hrs of battery capacity. For example I have 3 105 amp agm batteries so I need at least 315 watts of solar power. I have 340 watts of solar and on a clear day my batteries are charged in 5 hours.