200 Watts Solar Project on A Frame

[DanM-AZ]

This is what I mean by bullseye:

[rockfordroo]

Originally Posted by DanM-AZ

Real world experience with just such a setup:

1. The reason I mounted mine permanently on the A-Frame slope is because I am primarily a boondocker. I usually have the freedom to pick a spot that is clear of trees to the south of me, and I can park the front of the trailer facing south.
   
2. Even when I cannot park optimally facing south, facing east or west, I will have optimum sun angle to the panels for many hours -- enough to give my little hard-sided tent all the power it needs. An A-Frame does not have huge power demands. 200 watts is ample, maybe even overkill, for an A-Frame's power needs.
   
3. Even facing north, which I once had to do, the 200 watts was able to keep up with my power demands just from ambient, shaded light. I was surprised by that, but it is true.

I live in Arizona - the nation's bullseye for maximum solar "insolation". If you live elsewhere, you may not see quite such good results.

Didn't mean to imply it would not work; just not as well if you can't get set up in an optimal direction. Sounds like you are able to get around the negatives most of the time. Also, you're at about 34 deg N latitude; going farther north will reduce your performance; That's just about anyplace in the US except the Gulf Coast and Florida.

Glad it's working for you.

[DanM-AZ]

RockfordRoo,
My primary point of disagreement with you is your statement, "This is almost NEVER unless you have panels you can adjust to face perpendicular."

This statement is more true for flat-mounted panels, than it is for our slope-mounted panels. Flat-mounted panels will actually never be facing directly at the sun, while our slope mounted panels, when parked either east, south or west, will indeed be pointed directly at the sun for a number of hours.

[rockfordroo]

Originally Posted by DanM-AZ

RockfordRoo,
My primary point of disagreement with you is your statement, "This is almost NEVER unless you have panels you can adjust to face perpendicular."

This statement is more true for flat-mounted panels, than it is for our slope-mounted panels. Flat-mounted panels will actually never be facing directly at the sun, while our slope mounted panels, when parked either east, south or west, will indeed be pointed directly at the sun for a number of hours.

I probably didn't say it well, but that's exactly what I was trying to say. For flat mounted, it's never perpendicular. For you, it's pretty good if you're facing south, but it's only good for a period of a few hours if you're facing east or west. For example, if your roof (and hence your panels) is angled at 45 deg and is facing east, your incident light is going to be 45 deg to the panels as the sun comes up, and is also 45 deg to panels at high noon. It will be 90 deg to the panels sometime around, say, 9am, but won't stay there for long. Of course, after noon, it's in shadow. Shadow doesn't mean NO current flow, but it will be a lot less.

The real point of my post was so that someone doesn't run out and put these on his A-frame, then go to Alaska, back into some north facing campsite, and then wonder why it's not working. They can work very well, but that requires certain "circumstances."

[biscuit72]

Originally Posted by rockfordroo

I probably didn't say it well, but that's exactly what I was trying to say. For flat mounted, it's never perpendicular. For you, it's pretty good if you're facing south, but it's only good for a period of a few hours if you're facing east or west. For example, if your roof (and hence your panels) is angled at 45 deg and is facing east, your incident light is going to be 45 deg to the panels as the sun comes up, and is also 45 deg to panels at high noon. It will be 90 deg to the panels sometime around, say, 9am, but won't stay there for long. Of course, after noon, it's in shadow. Shadow doesn't mean NO current flow, but it will be a lot less.

The real point of my post was so that someone doesn't run out and put these on his A-frame, then go to Alaska, back into some north facing campsite, and then wonder why it's not working. They can work very well, but that requires certain "circumstances."

I mostly boondock so I will have the flexibility to point the trailer south. The reason for the panels, besides just needing another 'camper' project is to limit my generator usage. Also, I decided to reclaim some garage space this summer and will be storing the camper at a RV yard. The solar will keep my batteries topped off. I will be in Moab next weekend and will report back on how the setup performs. Time to start thinking about my next mod...maybe an inverter so I can toast my bagel in the morning without running the generator

[CharlieS3]

Very nicely done. I am an aircraft mechanic and am picky about the way things are done. You did a very nice clean job, with the wiring cleanly and appropriately secured. I think your idea of stronger struts is a great idea.

I installed 6 140W panels on the top of my motorhome. Keeps us nicely topped up and will produce over 200 amps on a sunny day. We can be very piggish with our power, running the microwave and the coffee pot, plus the tV at night, without any concerns. You will really enjoy the freedom this gives you.

I think the sloping mount gives you great options, most of the time. Occasionally, it won't. Occasionally, you'll be in a forest. Occasionally, it will rain the entire week.

C'est la vie.

Charlie

[GEugeneS]

Originally Posted by rockfordroo

I probably didn't say it well, but that's exactly what I was trying to say. For flat mounted, it's never perpendicular. For you, it's pretty good if you're facing south, but it's only good for a period of a few hours if you're facing east or west. For example, if your roof (and hence your panels) is angled at 45 deg and is facing east, your incident light is going to be 45 deg to the panels as the sun comes up, and is also 45 deg to panels at high noon. It will be 90 deg to the panels sometime around, say, 9am, but won't stay there for long. Of course, after noon, it's in shadow. Shadow doesn't mean NO current flow, but it will be a lot less.
"

Actually, they have available, and I installed, flat roof mounts that can be easily tilted up to about 30 degrees, lengthwise. So you would mount the panel lengthwise on the RV, then park your RV east/west and adjust the panel for maximum exposure to the sun. However, being old and lazy, I almost never do that even though it would take only a couple minutes. Maybe for our younger campers, or those who don't have an auxiliary generator.

[Ditchdigger]

SUB

[mnoland30]

My flat mounted 100 watt panel charges my 2 batteries easily. As a test, I turned all 17 of my lights on at 4 pm and left them on until 10 pm. My battery was at 91%. I bought all of my LEDs on eBay for less than $40 total. Some are better than others. I usually buy one to test and then order a bunch. We don't run microwave, tv, or AC. The furnace pulls about 3 amps, and the fans about 1 amp each.

[rockfordroo]

Originally Posted by mnoland30

My flat mounted 100 watt panel charges my 2 batteries easily. As a test, I turned all 17 of my lights on at 4 pm and left them on until 10 pm. My battery was at 91%. I bought all of my LEDs on eBay for less than $40 total. Some are better than others. I usually buy one to test and then order a bunch. We don't run microwave, tv, or AC. The furnace pulls about 3 amps, and the fans about 1 amp each.

Seems to me that your test really only tested your batteries. I could do the same test on my TT without solar.

I think test you need to do is pull your batteries down to 50% and then determine how long it takes your 100W panel to recharge those batteries.

The trick to all of this is to 1) install enough batteries to run whatever you want to run in a day, and 2) install enough solar panels to recharge those batteries on a "average" days sun. There are trade-offs related to both, of course.

[biscuit72]

So I just spent 4 days in Moab with friends. We had a little rain, some crazy high winds and sun. I camped in my usual spot which faces my camper pretty much due East. My battery voltage never drooped below 12.9 volts. It seems that the voltage for these (2, 6 volt Trojan AGM's) is fully charged around 13.0+ volts. I ran the fantastic fan a few times, my new led strip lighting (45 watts) and the furnace one night. My wife did not go on this trip and I did not use as much power as I usually when camping in colder weather, but I have not doubt that this system is going to preform, even when not pointed south. Only issue I had is the adhesive failed on one of the cable tie brackets.