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Old 12-28-2016, 01:02 PM   #1
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PV Solar for the Heap

Hi everyone,

After much research, I am finally putting solar in my rig, something I should have done from the beginning. Figured I'd post my plan for criticism / ideas for others. It will be a budget build for sure, but I think in sunny Colorado, it should work just fine.

First off, I have pretty low electrical demands. All my lights are LED, my inverter maxes out at 1000 watts, and when we dry camp, we usually bring a cooler. Not really counting on running the fridge with this setup, though the fridge is incredibly energy efficient.

As of right now, I have six batteries in the bus total - two 12v in parallel for starting, and four 6v 225ah golf cart batteries for the house. These two banks are isolated / joined manually via one of these:



I wired the battery bank on the side of the road in a few hours, so this switch is in the storage compartment where the aux batteries are. Really inconvenient and I am going to move the switch to inside the bus by all the other electrical business in the back.

I picked up one of these solar charge controllers:

https://www.amazon.com/Solar-Boost-3.../dp/B0179V9JQI

It is a very compact unit, very intelligent, with many settings, and several uses, AND cost-effective. Crazy, right? It allows you to program different float voltages and settings for different types of batteries. What drew me most, however, is that you can either use 12-volt designed panels, or the higher voltage, higher efficiency 60-cell panels like you'd find on a house for grid tie systems, which operate at 24-36 volts. This unit is capable of reducing that panel voltage to whatever is the optimal charging voltage for your batteries at that time. It is much more efficient than a PWM controller as far as putting the juice from your panels to work.

In addition to this, it has an input for an optional battery temperature sensor, which you'd put near the batteries, so the computer knows what charging voltages are optimal at whatever temperature the batteries are at, increasing charging efficiency.

It ALSO has a 12 volt, 2 amp charging output for starting batteries.If you are parked for a long period of time and want the house and starting batteries disconnected, this unit will trickle charge them separately, given that there is enough sunlight. Excellent for me, since the bus is stored in a spot where it gets 8+ hours of sunlight per day.

I was planning on coupling this system with one 260 watt 60-cell panel from the following seller in Denver:

260 watt Solar Panels - New!!

Priced nicely at $160 each. I will build some sort of mounting system for them that allows me to pivot them if I want, but also to keep secure at highway speeds. The 260 watt panel should keep me safely under the maximum for the charge controller.

I will feed the wires through the roof with this plate:

https://www.amazon.com/gp/product/B0...A2X8N6V4HT8DJJ

And a few more goodies:

Fuse box (in and out style, no bus bar) - https://www.amazon.com/gp/product/B0...A2WCR1L7XCIL9L

ANL High-amp fuse holder for inverter and large 12 volt loads - https://www.amazon.com/gp/product/B0...A130UJC6EIIOR0

DC Circuit breaker for panel disconnect / protection (I might want to go with a lower-amp one...) - https://www.amazon.com/gp/product/B0...=A6AY1HFZHO49U

10 gauge cables with MC4 connectors (pretty standard for solar) to run through roof to charge controller - https://www.amazon.com/gp/product/B0...A2TN19FHI2Z5KL

I will be mounting the solar panel and charge controller at the back of the bus, across from my fridge (directly over the drivers side rear wheel) as there are already 2/0 lines to the battery banks there for the inverter, and mounting it there would be the shortest run, and would use existing runs. All I need to do is drill a few more holes for a couple more wires to relocate my battery selector switch, hole in the roof for the lines from the solar panel, and some smaller gauge wires to the starting batteries for the maintainer function from the charge controller. I don't currently have the battery temperature monitor, but I think I will get one, and run that as well.

I will draw up some amateur wiring diagrams shortly and make sure all my plans make sense.
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Old 01-12-2017, 12:04 PM   #2
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Picked up my panel from a seller in Denver, $160 for a 60-cell panel, like you'd put on a house. It is 39" wide and 65" long. 260 watt maximum, which should put us safely under the controller's 290 watt maximum.





Waiting on warmer weather for installation! I came up with a pretty simple way to make a mount that will allow this panel to be tilted in four different directions, using door hinges. I'll have to get up on the roof to adjust it, but it should work. I was also thinking about adding some cross bracing in the center of the panel, since this thing isn't designed for use on a vehicle.

More updates to come!
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Old 01-12-2017, 03:43 PM   #3
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Nice snag... the trouble I'm having right now is the only way I can get a decent price on panels is to buy a whole pallet of them... Nobody around here likes to sell single panels for any kind of reasonable price...
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Old 01-12-2017, 03:58 PM   #4
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Originally Posted by slaughridge85 View Post
Nice snag... the trouble I'm having right now is the only way I can get a decent price on panels is to buy a whole pallet of them... Nobody around here likes to sell single panels for any kind of reasonable price...
That's exactly what this guy in denver did. He buys them by the pallet and marks them up a bit, but they're still substantially cheaper than buying one and having freight shipping. He is just some honest dude who is into solar and wants to help people out. Try searchtempest.com, it searches Craigslist in a certain radius and you might find more Craigslist sellers. Where in kansas are you? CO isnt that far!
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Old 01-12-2017, 04:05 PM   #5
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I'm in eastern ks. I wouldn't think twice about hopping in my honda and zipping out to CO for some decent priced panels... except that the transmission just went out and my other options are a f150 that gets ~13mpg or a 72 nova that gets ~14mpg or the bus that gets 10... There is a guy in KC, he just never has any panels when I have the money and then after I drop a couple g's on my kids college tuition he has LOTS available...

I'll be interested to see how that particular panel works out for you. It's a brand and model I've been considering for a while.
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Old 01-12-2017, 04:46 PM   #6
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Check out this guy too: Sunelec.com

Prices as low as 38 cents per watt. He is generally THE lowest price anywhere. He has some amazing prices on "B" grade panels, ie, panels with tiny cosmetic blems that do not alter either the power output or the warrantee. Warehouses in Los Angeles, Phoenix, and Miami. Read his blog too. The guy is a trip! Even has free panels (shingles, really) that are recycled and yours for the asking.
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Old 01-12-2017, 07:03 PM   #7
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I just got 6 250 watt panels delivered to my door for 1300.00 from ebay. it was a drop ship from ca. 30 year warranty . I paid over 5 bucks a watt for my first panels 15 years ago.
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Old 01-12-2017, 11:14 PM   #8
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So-called "Grid-tie" panels with 60 cells are the cheapest way to buy PV. Another benefit is that most manufacturers make them, all at about the same power, so if one breaks you can easily find a replacement with similar Vmp and Isc, even if it's from a different company. I suggest mounting your panels inside support frames to reduce the load on the panels' own frames, then if you want to get fancy and tilt them you attach the tilting mounts and support struts to the support frames - this way you don't need to attach any hardware to the panels themselves. I've got eight Grade B Sharp grid-tie panels set up this way, and they're working well (except in this lousy rain!).

John
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Old 01-14-2017, 01:59 PM   #9
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Quote:
Originally Posted by slaughridge85 View Post
Nice snag... the trouble I'm having right now is the only way I can get a decent price on panels is to buy a whole pallet of them... Nobody around here likes to sell single panels for any kind of reasonable price...

Freight is very high on panels so try to find local. Plus if they are damaged in shipping you will have to fight with both delivery and company.

We finally found local that would break up pallet. Just ask if they will sell a couple. Keep looking and good luck.
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Old 01-14-2017, 02:05 PM   #10
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Originally Posted by slaughridge85 View Post
Nice snag... the trouble I'm having right now is the only way I can get a decent price on panels is to buy a whole pallet of them... Nobody around here likes to sell single panels for any kind of reasonable price...

Also try Loews or Home Depot. They sell panels so does Costco. We bought a solar kit from Home Depot last year but sent it back till Florida bill passed for DIY private solar. Now we went al lout to put on a utility trailor we've had for 15 or so yr.s.

https://youtu.be/WfH4fnBNjSE
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