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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Ed on February 17, 2015, 01:33:41 pm

Title: Another way to do solar
Post by: Ed on February 17, 2015, 01:33:41 pm
With all of the discussions of solar in several threads, I'll offer what I am trying.

My thought process, simply stated, was that carrying the panels in one of my bays and then positioning them on the ground would be more efficient than mounting them on the roof.

If I stored the panels upright, on the long side, they wouldn't take much space in a bay. Unfortunately, standard 26 inch panels wouldn't fit. AM Solar sells 21" wide panels that they designed to fit in narrow RV roof spaces. They are 135 watts and fit my storage space perfectly.

I made up some swiveling, adjustable legs from aluminum C channel I had left over from some other project.

I finished the electrical part of the install just in time for Quartzsite in January. By keeping the panels oriented to the sun, 2 panels replaced all of the amp hours that 3 of us used (wife and 20 year old son) each day. At first we were cautious with our usage but started increasing it, including using the microwave on inverter, when we saw that we were replenishing our usage each day. We didn't run the generator at all in 5 days with only 270 watts of solar.

At Q, some of us started experimenting with the panel angles. Using Ron's very cool Fluke Clamp On ammeter(I bought one, Ron) we measured output with a panel flat on the ground and then angled at the sun. There was a full 50% increase in amps output when we raised the panel to an optimum angle.

Another reason that 2 panels did so well was that I positioned them facing east and almost perpendicular to the ground to catch sun up. I was getting good output for 2 hours before the fixed panels facing south were getting much, if any.

When we left the coach, I just positioned the panels for maximum exposure for the time we were gone.

Conditions at Q were ideal but since then I have added a third panel for those less than ideal days.
Dry camped at San Simeon State Park on the central coast of California last week and using all 3 panels the controller was in float mode early in the day.

The very experienced solar forum members at Q predicted that I would have the panels on the roof by next year at Q and they may be right, but so far I'm getting a kick out of doing it this way.

If anyone is interested, I'll post details on the storage, hook up, and theft prevention that I've done.









 
Title: Re: Another way to do solar
Post by: Kemahjohn on February 17, 2015, 02:09:33 pm
Many years ago I designed a simple transistorized servo system to constantly keep solar panels pointed at the sun-- one axis only.  Very simple and easy to build.  I'll see if I can find those plans.  Been a long time so I'm not promising I'll find it.
Title: Re: Another way to do solar
Post by: Tom Lang on February 17, 2015, 02:24:32 pm
Very good.

What's the trick in getting a 40' coach into San Simeon, with a 35' limit?  We used to go there, but not since buying the 38' coach.
Title: Re: Another way to do solar
Post by: Ed on February 17, 2015, 02:30:59 pm
Many years ago I designed a simple transistorized servo system to constantly keep solar panels pointed at the sun-- one axis only.  Very simple and easy to build.  I'll see if I can find those plans.  Been a long time so I'm not promising I'll find it.

Wow! That sounds interesting...
Title: Re: Another way to do solar
Post by: Pierce & Gaylie Stewart on February 17, 2015, 02:32:24 pm
OK, here are the drawbacks to doing it that way. It's a pain to remove panels and set up. Winds and or dogs will eventually knock one over and break it. I have lost two 100 watt panels this way. It only cost us about $160 per 280 watt panel (plus controller but you need one anyhow) so put four on the roof mounted in a fixed position as I'm not about to climb up on the roof to tilt them. A tumble off accident is just waiting to happen. Just climb up occasionally to Windex them. Charges fine even in cloudy weather.

Pierce
Title: Re: Another way to do solar
Post by: Ed on February 17, 2015, 02:37:44 pm
Very good.

What's the trick in getting a 40' coach into San Simeon, with a 35' limit?  We used to go there, but not since buying the 38' coach.

Tom, no chance of getting 40' into the lower part of San Simeon but the Washburn primitive part of it is good. The web site shows a 31' limit for Washburn but at least 1/3 of the sites can take a 40' coach if you back in. I've been there several times. Rangers and Hosts are very cool about it. Never had a problem.
Title: Re: Another way to do solar
Post by: wa_desert_rat on February 17, 2015, 02:40:57 pm
On our sailboat and in our little 21' travel trailer (a 1970s Streamline - think Airstream spinoff) I happily moved panels around. Lashed to the mast or to the boom on the boat and tied to the trailer tongue of the TT. Just moving them every couple of hours can help two 100-watt panels do the job of 400-watts (almost). It really does help. But we were careful about securing ours. Never had a bird poo issue either. But I admit that the roof-mounted panels are easier. Not to say that you cannot do both (but it's not easy).

Craig
Title: Re: Another way to do solar
Post by: Ed on February 17, 2015, 02:46:04 pm
Pierce, so far set up and teardown have been very easy.

I'm going to slot the legs to accept tent stakes.

Dogs....no solution to that potential problem yet. Maybe when they lift their leg the sizzle sound from the heat will scare them away.

This is just another way to use solar panels. I'll add you to the list that predicts they will be on the roof next year.

Title: Re: Another way to do solar
Post by: Ed on February 17, 2015, 02:49:09 pm

Craig, I agree. And its kind of satisfying seeing the results.

Not mentioned yet is that I can park under a tree for shade and still get full sun on the panels. FWIW
Title: Re: Another way to do solar
Post by: Chuck & Jeannie on February 17, 2015, 03:23:12 pm
If anyone is interested, I'll post details on the storage, hook up, and theft prevention that I've done.
So what is your theft prevention...Smith & Wesson, or 12 Gauge?
Title: Re: Another way to do solar
Post by: Pamela & Mike on February 17, 2015, 03:27:16 pm
Ed,
We do just as you. We have 2 panels with a total of 180w of solar.  One of the panels has been used on 3 different coaches over the years, as we got it shortly after Solarx started marketing them. Back then we had to build our own voltage regulator as there were nun on the market that we knew of, yes long before the web. We set them up on custom made tripods so we can park over in the shade if desired. Our results are about the same as yours. We have found that our limiting factor is the holding tank size rather than electrical sizing.
I for one would like to see your follow up on storage and set up to see if there is a way we can improve our set up.

Pamela
Title: Re: Another way to do solar
Post by: toyman on February 17, 2015, 03:28:23 pm
I have 500w on the roof of the Lazy Dazy, last year, in Idaho, I didn't see enough charge to run a flash light. Always in the shade. I'm probably going to do portable for the FT. I may carry them on the roof of the tow'ed, if they don't fit other places.
Title: Re: Another way to do solar
Post by: Roland Begin on February 17, 2015, 04:11:50 pm
Can't charge your batteries with solar while going down the road if the panels are in the basement. When we head to Maine we continue boondocking as long as we can . Batteries are always charged at the end of a day's driving. Not saying you will have your panels on the roof next year as it is "different strokes for different folks", just too much bother for me.

Roland
Title: Re: Another way to do solar
Post by: Ed on February 18, 2015, 12:15:24 am

Pamela,

You were really pioneers. That's very interesting.

I'll take some photos of the storage.
Title: Re: Another way to do solar
Post by: Tigratrus on February 18, 2015, 12:52:51 am
If you're looking at portable and lightweight, have you looked at the flexible panels?

There's quite a bit on Technomadia about their flat panel trials using PVC pipe frames for tilting. I tend to think that the standard rigid panels would be easier to work with, but the flexible panels are a LOT thinner and lighter.

Might do a ground array to supplement the roof panels, love hearing what others have tried and how it's worked out. :-)

James
Title: Re: Another way to do solar
Post by: Tom Lang on February 18, 2015, 01:08:52 am
If you're looking at portable and lightweight, have you looked at the flexible panels?

There's quite a bit on Technomadia about their flat panel trials using PVC pipe frames for tilting. I tend to think that the standard rigid panels would be easier to work with, but the flexible panels are a LOT thinner and lighter.

Might do a ground array to supplement the roof panels, love hearing what others have tried and how it's worked out. :-)

James

It wouldn't be pretty to some, but how about sticking flexible panels on the sidewall facing the sun?  Pretty good angle in the winter.
Title: Re: Another way to do solar
Post by: Pamela & Mike on February 18, 2015, 07:21:48 am
It wouldn't be pretty to some, but how about sticking flexible panels on the sidewall facing the sun?  Pretty good angle in the winter.


Tom,

We have ran across a fellow out in the desert South West that has done something similar. He has some brackets that hang off the side of the coach (it is a early 90's U280) and puts his panels on that. The panels are not flexable but rigid. I have some photos somewhere but can't find them this A/M.

Pamela & Mike
Title: Re: Another way to do solar
Post by: fouroureye on February 18, 2015, 08:50:43 am
"Scotty, we need more Power, what about the Warp Drive? (http://www.foreforums.com/index.php?topic=20148.msg145362#msg145362)

Does this look familiar? Wayne Macauley spoke to him..
Title: Re: Another way to do solar
Post by: Pamela & Mike on February 18, 2015, 09:10:56 am
John,

Yes that is the rig. We have some close ups of the mounting system somewhere. We talked to him on one of our trips to western New Mexico or Arizona.

Pamela & Mike
Title: Re: Another way to do solar
Post by: toyman on February 18, 2015, 09:11:15 am
A friend of ours removed his awning, mounted a awning rail on his panels. He can then extend them as he wants, and shade the side of his RV. Works for him.
Title: Re: Another way to do solar
Post by: Ed on February 19, 2015, 10:22:18 am
Here's a photo that shows how the panels are stored.

The bottom "trays" are made from 2.5" pvc conduit. They are lined with pipe insulation. I added a strip of 1/8" luan on top of the foam so the panels would slide easily.

Edit: Photo didn't show. Better read the instructions again...
Title: Re: Another way to do solar
Post by: Ed on February 19, 2015, 06:37:16 pm
Let's try again....

Title: Re: Another way to do solar
Post by: lgshoup on February 19, 2015, 07:11:15 pm
Toyman, I've always thought the best place for solar would be as replacements for window awnings. Tip them as you want. What an idea ^.^d
Title: Re: Another way to do solar
Post by: John Haygarth on February 20, 2015, 10:20:45 am
Larry the only problem with that one is very limited area on each side, and one side would not be doing much all day long?
Now if they made a roll up panel for main awning then you may have something!!
JohnH
Title: Re: Another way to do solar
Post by: Pierce & Gaylie Stewart on February 20, 2015, 11:28:45 am
With almost 1200 watts up top and only costing under $650 for the panels, they not only keep the coach cooler with all the space they take up (mounted with about 1 1/2" air space under)  but don't even worry about parking in the shade or pointing in any particular orientation. Just have to remember to turn on the controller.  ;) With the low sun in Quartzsite, we still peaked at 550 watts once the sun was up. With LED lights and LED-LCD TV/satellite receiver, there is not much draw except for the microwave and latte maker in the morning so floats in a couple of hours. We do shut off the inverter during the night.

Pierce