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offgrid
Senior Member
Joined: 23 Jul 2018
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Topic: new R-Pod owner Posted: 26 Sep 2018 at 1:17pm |
GlueGuy, Brent S has already bought a 100W module and controller, so I'm assuming that's going to be a 12V module and a PWM controller. There are a couple of higher voltage 120W modules out there but they're rare because they have to use cut cells, and I haven't seen a high voltage one at 100W for awhile.
The ones you're using with Voc in the 35-40V range are probably going to be 60 cell residential grid tie modules or maybe 72 cell commercial project modules with 250-400W ratings. Those plus an MPPT controller are a great choice if you need that much solar charging. Turns out the length of the 72 cell modules is almost exactly the same as the width of an rPod so my plan is to mount those edge to edge on mine. But I'm trying to run my air conditioner from them, which most folks will think is crazy...
Brent S, as GlueGuy says you can mount your controller either at the solar module or at the battery, or as many folks do, in a compartment and then run over to the battery. Since its all operating at 12V the voltage drops will be the same either way in this case.
The size solar panel you bought is fine and meets most rPod folks solar charging needs, not counting any big AC loads like your microwave or air conditioner. Once you use it and the trailer a few times you'll get a good idea what your actual needs are.
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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold
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GlueGuy
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Joined: 15 May 2017
Location: N. California
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Posted: 26 Sep 2018 at 1:28pm |
I have a couple modules in the garage that are 150 watts each with OCV of 37 volts. They were meant for off-grid applications of 24 or 48 volts depending.
The newer ones we've been using for several years now are in the 250-350 watt range, and they are quite a lot larger; they would be very impractical for an R-pod solar system. With newer controllers they can be either off-grid or grid-tie. Sure can cook though!
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bp
2017 R-Pod 179 Hood River
2015 Ford F150 SuperCrew 4WD 3.5L Ecoboost
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offgrid
Senior Member
Joined: 23 Jul 2018
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Posted: 26 Sep 2018 at 2:33pm |
Yeah, my buddy at Ameresco designed some in the 120-150W range at 24V. A couple other PV companies have them too. Pretty specialized product though, most companies are doing what you're doing now and using the standard resi or commercial modules which can be bought for less than $0.50/watt.
I don't think the big modules are impractical if you roof mount them and don't try to move them around. Lots of RV'ers do that now. I'm too lazy to move them around anyway.
The 72 cell ones are about 77-78 inches long by 39-40 wide. rPods are about 77-78 inches wide. I plan to mount 3 across on standoffs on my 179 above the roof after I yank off that POS roof air and replace it with an efficient and quiet mini split and yank off the TV antenna which I never use. That'll give me about 1050 nominal watts and the air gap will keep the PV array and rPod cooler too. But like I said, most people would think I'm crazy.
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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold
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Brent S
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Joined: 25 Sep 2018
Location: SE USA
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Posts: 21
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Posted: 26 Sep 2018 at 2:40pm |
Yes my system is a 12v 100w with a 20 amp pwm controller. It came pre wired supposedly, so will see if I want to add a larger/longer wires. I haven’t even opened the box from amazon yet, but hope to at least look at it tomorrow.
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offgrid
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Posted: 26 Sep 2018 at 3:46pm |
20A controller is good, you should be able to add at least one more 100W module to that if you find it necessary. I don't know if you are aware of this yet but all the solar cells are in series so even shading one cell bottlenecks the whole dang module. So when you're using solar modules, try to keep them completely out of the shade. I see you live in the SE as I do, I know that can be hard to do here because we like to camp under the nice shady tree canopy in the summertime...have fun!
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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold
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Brent S
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Joined: 25 Sep 2018
Location: SE USA
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Posts: 21
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Posted: 26 Sep 2018 at 4:00pm |
Thanks, I’m in NE Georgia, so sun isn’t usually a problem. Staying out of it can be! I researched campers a lot before deciding on the rpod due to its design. Can’t wait to take it out!
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offgrid
Senior Member
Joined: 23 Jul 2018
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Posted: 26 Sep 2018 at 4:10pm |
My daughter and grandson live outside Savannah. I'm in Hatteras NC, aka hurricane alley . We were in the WV mountains in our 179 for Florence, one of the reasons I bought it was to bug out. Luckily, it missed us here, no damage other than a few shingles . I looked at tons of trailers before I bought my pod this spring. You're going to love yours.
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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold
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Brent S
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Joined: 25 Sep 2018
Location: SE USA
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Posts: 21
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Posted: 26 Sep 2018 at 4:21pm |
I’ve seen more of the flexible panels out there now and think they would be ideal for doing the whole roof, front and back. I’m sure you could get an ac to run, just not sure of the cost/benefit being worthwhile. Cool to have the option though.
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Brent S
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Joined: 25 Sep 2018
Location: SE USA
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Posted: 26 Sep 2018 at 4:25pm |
I’ve been a prepper most of my life, which is partly how I justified buying a camper. Seriously after growing up in Fla. with he hurricanes I was a prepper before I even knew what one was. Glad your home escaped any bad damage!
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offgrid
Senior Member
Joined: 23 Jul 2018
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Posted: 26 Sep 2018 at 4:33pm |
To be honest, I personally wouldn't take "flexible" modules if they were given to me, I used to design solar modules for a living and know too much about it. Solar cells are made of crystalline silicon, which is a (very) brittle material. Nuff said, don't want to start a debate on that...
My objective with the ac is to run it overnight during campground quiet hours, not to run it 24/7 from solar. So the main thing is to have a very efficient ac unit and a large battery bank. The solar is there to reduce the cost of generator runtime to recharge during the day.
The cost will be a few $K, mostly for the Li Ion battery.
The benefit? DW has told me she won't camp with me on the beach here on the OBX without ac in the summer. Can't say I blame her, and neither of us like the private campgrounds with hookups around here much. So right now we either have to drive all the way to the mountains where it's cool or not camp.
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1994 Chinook Concourse
1995 RV6A Experimental Aircraft
2015 Rpod 179 - sold
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