Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Paul Smith on April 18, 2013, 03:45:47 pm

Title: Where To Locate a Solar Panel?
Post by: Paul Smith on April 18, 2013, 03:45:47 pm
Hello!

I plan to have AM Solar add a solar panel this Summer. 

My first thot was to put it over the 3 AGM  house batteries - which are right behind the driver (and a bit below ;o). 

But then I thot it might be better to put it near the fridge location to ease wire entry thru the roof via the fridge 'exhaust pipe'

What do you recommend?

best, paul
Title: Re: Where To Locate a Solar Panel?
Post by: P. Wyatt Sabourin on April 18, 2013, 03:53:07 pm
Near the fridge for ease of wiring, but away from anything which could shade the panel. A shaded panel may produce only 10% of the rating. 
Title: Re: Where To Locate a Solar Panel?
Post by: Roland Begin on April 18, 2013, 04:04:15 pm
Near the fridge for ease of wiring, but away from anything which could shade the panel. A shaded panel may produce only 10% of the rating.
And it does not take a lot of shade either.

Roland
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 18, 2013, 06:08:32 pm
They at Amsolar know what to do and Micheal is a good installer. They do not work well if even a slight shade covers part of one. Go with the 150watt ones but why not put a couple up there while at it. Faster charge rate and use minimum #6 wires from roof.The wire will come down back of fridge and then under and into the battery bank and have them put the remote in the side of cabinets (drawers) in kitchen. I also had the Trimetic put in for ease of view while driving. You need a breaker from solar and also from controller. Do it now as you will be adding more panels later I am sure. Great rv spot there too next to the pond. Greg and Deb are rvers too so they have it fixed up nice. The office for waiting in is first class. You will be well looked after.
John h
Title: Re: Where To Locate a Solar Panel?
Post by: Paul Smith on April 18, 2013, 06:51:10 pm
Thanks, John.

Yes, I know Amsolar. Good folks. I had 2 earlier motor homes there. I'll think about 2 150 watts

Yes, I'm getting:

SunRunnerâ„¢ Signature W/100/60/2 System | SunRunnerâ„¢ Signature Systems (http://www.amsolar.com/home/amr/page_208_65/sunrunner_signature_w100602_system.html)

which is good for 1,000 watts.

I'm not disposed to getting tilt bars. (I'm not allowed on roofs anymore - SWMBO orders ;o)

best, paul

Quote
They at Amsolar know what to do and Micheal is a good installer. They do not work well if even a slight shade covers part of one. Go with the 150watt ones but why not put a couple up there while at it. Faster charge rate and use minimum #6 wires from roof. You need a breaker from solar and also from controller. Do it now as you will be adding more panels later I am sure. Great rv spot there too next to the pond. Greg and Deb are rvers too so they have it fixed up nice. The office for waiting in is first class. You will be well looked after. John h

Title: Re: Where To Locate a Solar Panel?
Post by: P. Wyatt Sabourin on April 18, 2013, 08:07:18 pm
The effect that shade has on the output of a panel depends to some degree on how the panel is manufactured. The least expensive panels will drop to zero with just the shade of your hand. Most panels today do not do that. Also a cloudy sky reduces output. When in Canada in the summer, my panels only produce about half as many amphours a day as they do in California during the winter.
Title: Re: Where To Locate a Solar Panel?
Post by: Jon Twork on April 18, 2013, 08:41:36 pm
A lot depends on what amount of real estate you have available for panels.
Usually a row down the right side of the rig works depending on your model, I guess.
I would have a good aluminum fabricator put together a 25'-30' or more, aluminum base frame and a tilt frame powered by linear actuators at both ends.  This would allow you to have as many panels as you have space and to be able to tilt them with the touch of a button.  Makes it easy to wash the panels too.  What with the cheap price of panels these days I would try to get to a 1000 watts. 
Try Solar Panels, PV Systems and Inverters Distributor (http://www.sunelec.com) for pricing and to keep the other dealers honest.
Regards,
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 19, 2013, 12:27:25 am
 Paul, excellent price that Amsolar have on the Morningstar 60 MPPT comtroller, others are charging a lot more. I made my own tilt bars for panels as I have 5 panels now. Copied their design then made mine for 1/8 th the price and in stainless too. I have both 150's and 100 watts.(total 700) When I stopped in at Boxing day to pick my last one up they were all out of 150s so got the 100. I will soon be rewiring the whole system with #2 wire and have made my own combiner box to handle the larger wires and future add ons
John H
Title: Re: Where To Locate a Solar Panel?
Post by: John S on April 20, 2013, 09:26:40 am
So has anyone attached solar to the isolator by coming down inside the rear cap.
Title: Re: Where To Locate a Solar Panel?
Post by: wa_desert_rat on April 20, 2013, 12:02:03 pm
One of the great advantages to MPPT controller is the ability to move to 24v panels which are much less expensive for equal wattage than 12vdc panels. Wire sizes are also reduced because the current is halved. I have two 240-watt panels and two 60-w unisolar panels (in 12vdc). The unisolar are long and slender and lay flat on the coach with a self-stickum. They are much more friendly to random shadows than the big panels. Two in parallel and two in series down to the MPPT controller.

Right after the wiring in the engine room is finished and the Wineguard goes away.

Craig
Title: Re: Where To Locate a Solar Panel?
Post by: Don & Tys on April 20, 2013, 01:04:14 pm
Craig,
Could you share some info about your 240W solar panels? Specifically, what make are they, how much, and possibly most importantly, what are their dimensions? I have two of the 136 watt 24V Unisolar panels and two of the 68W 12V Unisolar the panels waiting to be installed. Of course my plan is to wire the 2 24V panels in parallel with each other and then in parallel with the 2 12V panels which will be in series with each other. If I maxed out my space on the roof, I could double that with six more of the 68 watt panels. But I'm also considering the option of adding some conventional panels instead in the future for the upgrade path. I do like the shade tolerance of the Unisolar units.
Thanks, Don
One of the great advantages to MPPT controller is the ability to move to 24v panels which are much less expensive for equal wattage than 12vdc panels. Wire sizes are also reduced because the current is halved. I have two 240-watt panels and two 60-w unisolar panels (in 12vdc). The unisolar are long and slender and lay flat on the coach with a self-stickum. They are much more friendly to random shadows than the big panels. Two in parallel and two in series down to the MPPT controller.

Right after the wiring in the engine room is finished and the Wineguard goes away.

Craig
Title: Re: Where To Locate a Solar Panel?
Post by: wa_desert_rat on April 20, 2013, 03:17:27 pm
I'll have to check on the brand when I go to the shop either later today or tomorrow (baby sitting right now). The panels are big but no bigger than two 12v panels with half the wattage. I bought them last year just before the new import duty went into effect but I'm not certain they were Chinese. About $1 per watt per panel. The DW moved them to the back wall in the shop pending the completion of the dreaded engine wiring project.

My plan is one panel forward over the passenger seat and one aft where the roof carrier box sits now. Then the narrow unisolar panels along the edge of the coach port and starboard. I'm hoping that the flex in the unisolar panels will allow them to follow the curve of the coach roof.

Your parallel - series - parallel is the same configuration I'm going to use. The MPPT controller should handle that well.

I also have mounting feet that I'll use the high-adhesive 3M tape on... with adjustments for tilting when appropriate. Satellite dish is going as is the Wineguard antenna and the storage box. May increase fuel mileage too. :D

Craig
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 20, 2013, 04:56:36 pm
This is my roof layout of panels and wiring. I will be putting a new made combiner box before the fridge vent insyead of all the wires going to  the vent fixed box now, when I do the cable upgrade. The second 2 pictures are of the deflectors I have infront of panels to keep wind from causing a whistle. I made them again out of aluminum and taped them too roof then Dicor.
JohnH
Title: Re: Where To Locate a Solar Panel?
Post by: wa_desert_rat on April 20, 2013, 05:00:01 pm
John... those deflectors are brilliant!

Why are you upgrading the wiring? Have you detected losses in the system?

Craig
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 20, 2013, 05:21:07 pm
yes I am losing my mind!!!!
No losses, just that as I have upgraded the battery set up for hopefully more even charge (I do not even know if they were not being charged unevenly) but  figured it is a good move using Bus Bars for connecting each battery, that while at it change to a larger copper stranded wire for panels to breaker box then to controller then to breaker and on to bar and fuse link. The recognized loss of volts is usually around 2% so hope with bigger wire I can get rid of that. Need to keep working on coach for something to do!!!
I have also convinced Ruth that I really need a pit for underneath stuff. So this summer I will dig out one about 12 ft long as this will cover engine and tranny and driveshaft all at once then just turn the rig around for the other end. It will have a good 8" pad around with rebar and a sectional steel cover so I can turn the wheels over it. Drop in steel tubing across the opening with checkerplate on should do fine. Luckily we are all sand for 100 ft down so easy digging.
picture is one I posted before but shows the new battery hookup
John H
Title: Re: Where To Locate a Solar Panel?
Post by: Paul Smith on April 20, 2013, 05:32:48 pm
I don't understand your comment about wiring currently going to "vent fixed box now"

And where will you put the wiring when you put the new made combiner box in front of the fridge vent?

best, paul

Quote
This is my roof layout of panels and wiring. I will be putting a new made combiner box before the fridge vent insyead of all the wires going to the vent fixed box now, when I do the cable upgrade. The second 2 pictures are of the deflectors I have infront of panels to keep wind from causing a whistle. I made them again out of aluminum and taped them too roof then Dicor.
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 20, 2013, 10:23:33 pm
yes Paul, at the moment the wiring from panels goes to a box fastened to the side of fridge vent stack (common) and the one I have made is free standing and no connections will be on that vent, just wires going thru the side then down the stack. The wires will still follow the same route just connections will be changed because of the larger wiring. The box I am using is a 6x6" electrical box and I have drilled holes thru the sides for wires in on one side and wires out on opposite side. The actual joining of wires will be in a ground bar that I cut and added a heavier copper clamp for pos and neg out. Here is a pic of that box
John
Title: Re: Where To Locate a Solar Panel?
Post by: wa_desert_rat on April 21, 2013, 11:11:30 am
I have a free-standing junction (combiner) box too. I plan to mount it aft of the refrigerator vent with 3M tape.

John... are you using #2 wire from the panels to the J-box? Or from the J-box down to the regulator? I can see some advantages to using larger wires on the rooftop both physically and electrically. Larger wires are less likely to be blown around by the slipstream underway and there would be some advantages due to resistive losses. I may re-think this, myself. #2 seems kinda big, though.

I like the idea of a working ditch under the coach a lot!! Not sure if I like it enough to go rent a backhoe and do it, though. After cataract surgery I've had problems working while laying on my back for some reason.

The city here is a b***ch to work with and I doubt I could get a permit to build one of those outside. The inspectors are all entrenched and obstructive to the max which has resulted in many businesses relocating outside of the city limits to build facilities (and others deciding not to come her at all).

Craig
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 21, 2013, 11:59:06 am
after the box all way to battery etc hookup. I also have #4 if I find the wire too heavy to form but I think it is going to be ok but tough.
I do not think I will use a backhoe as the sand here is firm but easy to dig thru, and there are no rocks in it. I had to dig a trench from our guest house to house septic tank a few years ago for the sewer line and electrical/phone and satellite cable, water and did a 18" by 4ft deep  about 60ft long and it took 2 of us about 4 hrs so really easy. Luckily as I am a Director of our local Volunteer District and covered by the Regional District I can talk of record to Engineers etc and they know my work habits so they said just make sure it is safe for walking over and no kids can get in it. One nice thing on being in a rural community I guess.
John H
Title: Re: Where To Locate a Solar Panel?
Post by: Paul Smith on April 21, 2013, 01:32:53 pm
Good question, John. But why go inside?

Put the roof combiner box at the top left corner of the FT (looking a the rear of the FT).

Run wires down on the outside and thru a hole into the engine compartment.

The question is whether AmSolar's TriStar-60 MPPT controller can survive engine heat.

Am I missing something here?

best, paul

Quote
So has anyone attached solar to the isolator by coming down inside the rear cap.
Title: Re: Where To Locate a Solar Panel?
Post by: Paul Smith on April 25, 2013, 04:30:19 pm
The rear roof of our U320 has a 7ft by 7ft clear area.

I like AmSolar's SunRunner(TM) Signature W/100/60/2 System

with 2 GO150 Solar Panel (http://www.amsolar.com/home/amr/page_33_20/go150_solar_panel.html) s (150 watt each)

The Combiner Box will fit nicely near the left rear corner of the roof.

Then the wires can go down the outside of the motor home about 4 ft and then through a hole into the engine compartment.

Then forward about 8ft to the Controller. If the Controller CAN survive the environment of engine heat it can be on the engine side of a wall. Otherwise the Controller can be on the bedroom side of the wall.

Then short wires to the motor home's Isolator (through the wall if the Controller is on the bedroom side of the wall).

Is there a reason my Link 2000 will not suffice for instrumentation?

Will the Isolator be a good enough place for Am Solar's Controller to sense the house battery voltages?

Am I missing something here?

best, paul

Quote
So has anyone attached solar to the isolator by coming down inside the rear cap.
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 25, 2013, 05:58:31 pm
I do not like the idea of wires going down the back end and much prefer the vent down the fridge and I am sure AMSOLAR would suggest this too. Less wire run as the controller goes nice in the wall of centre bay then up across to batteries and remote panel in kitchen cabinets. If you look at my picture in the "sewer hose" discussion you will see my controller on the wall. I am taking that off and putting it on a wooden panel with the breaker box next to it. Fits nice and easy to get too, and, it does not get hot and dirty as in engine location. The leads from controller do not go to isolater but to a fusible link(shunt) for neg and the positive to batteries. There is a temperature sensing line to go to batteries too.
They know what to do. Main thing is keep wires as short as possible OR use heavier wires to keep voltage drop as low as possible.
John H
Title: Re: Where To Locate a Solar Panel?
Post by: Tim Fiedler on April 25, 2013, 06:24:37 pm
Hmmmm, should I run some wire next week for future solar install (Dave Head will want solar when he buys my coach.... ;-)) when I have refrigerator out for install of residential?
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 25, 2013, 07:34:09 pm
Tim as long as you leave roof vent on it will not be a problem to do later.
John h
Title: Re: Where To Locate a Solar Panel?
Post by: Keith and Joyce on April 26, 2013, 12:32:44 pm
I used two stick-on flex panels that are about 18" x 18' (yes feet).  Stuck them down along each side of the roof and ran the wires down the fridge vent.

Keith
Title: Re: Where To Locate a Solar Panel?
Post by: Jim Frerichs on April 27, 2013, 11:32:18 am
Keith,

If we may ask, what brand, wattage output and price for your panels?

Jim

2002 U320
Title: Re: Where To Locate a Solar Panel?
Post by: Pierce & Gaylie Stewart on April 27, 2013, 11:40:23 am
Just noticed these 230 watt panels on Craigslist: SOLAR PANEL-230 WATT (http://sacramento.craigslist.org/bfs/3768908908.html) . Seems like a great deal at $.80/watt. They look like the panels in the new outside display at Home Depot. Anyone use this brand yet?

Pierce
Title: Re: Where To Locate a Solar Panel?
Post by: wa_desert_rat on April 27, 2013, 12:33:29 pm
I used two stick-on flex panels that are about 18" x 18' (yes feet).  Suck them down along each side of the roof and ran the wires down the fridge vent.

My flex panels (unisolar) are not as long as yours but only 60-watts (@12vdc). They are much less prone to shadow problems due to the way they're wired. I should have bought a third one to use on my 21' Streamline (fishing trip) trailer; just have two 30-watt hard panels for that. You can see the fishing trailer with the little 30-watters in use at Adventures in Paddling the Pacific Northwest (http://www.nwkayaking.net). Advantages to the little panels is that I can move them around as the earth rotates to keep them aimed at the sun. Those panels gave us enough power for TV, radio and lights for a week's vacation camping in So. Cal. (before we got the FT).

You don't actually HAVE to have a charge controller, either; as long as you perform that function yourself. And if you use a germanium diode instead of a silicon diode you won't have that 0.6volt drop; but germanium diodes of sufficient current capacity are hard to find. Ebay is probably the only hope. I had one on our sailboat in the 1980s and it worked beautifully.

On the trailer I just connect the panels directly to the battery (they have built-in diodes) and use a digital voltmeter to determine when they need to be disconnected (once the batteries reach about 14.5vdc). You could do this with larger panels if you were careful but I'd worry about wind throwing bigger panels around but if you don't want to mount the panels on the roof top it's certainly do-able. I wouldn't get anything larger than the panels John Haygarth is using and I'd figure out a decent way to secure them.

Craig
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 27, 2013, 02:58:23 pm
Craig, they were my sentiments too as I thought those 230 ones are too big(even tho' they are only 9+ inches longer and a few wider) but lying flat they will vibrate more. Mine are fine and frame is solid.
I have just mounted my new breaker box and controller to a 3/4" plywood panel and wired it up using the #4 cu wire as the #2 was way too tough for these bends. I used corrosion inhibiter on connections (cu to Al) so soon I will wire from box on roof to this breaker with #2 cu as that should be easier??? then it is too Batteries etc.
Here is the panel.
John H
Title: Re: Where To Locate a Solar Panel?
Post by: Pierce & Gaylie Stewart on April 27, 2013, 05:56:32 pm
Thought I might pick up a couple of the 24V panels but want to know what brand MPPT controller works/priced well in the conversion. Anyone done this before?

Thanks in advance.

Pierce
Title: Re: Where To Locate a Solar Panel?
Post by: John Haygarth on April 27, 2013, 07:12:51 pm
check out Morningstar website as they are one of the best. The MPPT series is what you want.
A 60 amp is around $550
John H