Foretravel Owners' Forum

Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: fatheeler on September 20, 2023, 01:19:30 pm

Title: Solar Panel Install
Post by: fatheeler on September 20, 2023, 01:19:30 pm
I am getting ready to install 5 435 watt SunPower panels on the roof of the rv after laying it out am a little concerned that I am to close to the edge of the roof, looking for a little guidance on this, the inside edge of the tape is where the pane
 Edge would be
Title: Re: Solar Panel Install
Post by: craneman on September 20, 2023, 01:40:22 pm
I would make the brackets able to be tilted to lift the outer edge of the panel for pressure washing under the panels. You are not walking on the roof with that setup.
Title: Re: Solar Panel Install
Post by: fatheeler on September 20, 2023, 01:50:34 pm
Yes sir my thought would  be 13/16 unistrut with home made 3x2 5052 ALM angle with a 87 degree bend to get it close to plumb so panel would sit fairly flat, running VHB tape along full length of the unistrut looks like I will have 6 1/2" between the panels for a path way

Thanks
Mike
Title: Re: Solar Panel Install
Post by: Rich Bowman on September 20, 2023, 04:22:34 pm
Remember to raise the outer edge of the panel (taller brackets) enough to account for the curve of the roof.

Rich
Title: Re: Solar Panel Install
Post by: fatheeler on September 20, 2023, 05:25:34 pm
Looking at it will be 2-1/2 " on the outside and 1" on the inside  that should get them close to flat so the charge controllers will play nice, mainly concerned about how close to the edge the panels will be and if it will create any kind of turbulence

Thanks
Mike
Title: Re: Solar Panel Install
Post by: Lon and Cheryl on September 20, 2023, 07:08:12 pm
I have 6 panels installed. I did not use the curved radius on the roof for any mounting points.
I mounted my panels on rectangular aluminum beams using hinges to secure them to the beam. The beams are mounted just before the curved roof radius, all mounted horizontal and both sides can be tilted to the drivers side.
All my panels can be easily tilted 180 degrees if needed. They can easily be removed by just pounding out the hinge pins.
Title: Re: Solar Panel Install
Post by: dbennett9 on September 21, 2023, 12:31:39 am
Your panels don't look like they are any closer to the edge than ours, and we have not had any issues.
Title: Re: Solar Panel Install
Post by: Barry & Cindy on September 21, 2023, 11:50:59 am
How are you going to safely step off the coach ladder on to the roof?
Title: Re: Solar Panel Install
Post by: Barry & Cindy on September 21, 2023, 12:01:42 pm
We used two long aluminum angles on each side of panels.  One angle screwed to roof structure cross beams.  The other angle bolted to panel's OEM bottom holes.  Then several fasteners keep the two separate angles bolted together.

Our idea was to physically attach roof beams and not use adhesive mounts that depend on the thin top surface of the roof being stable.  Panels are subjected to very high winds under panel that can greatly exceed coach speed when wind direction comes from direction of travel.  Panels need to be lifted off roof to keep them cooler as lower temperatures increase panel output.  A short vertical wind-deflector panel could be mounted in front of panels to deflect air from going under panel while driving down the road.  We did not want to drill mounting holes in panel, to preserve manufacture's warranty.

Hinges could be used to allow tilting side to side.  We used to tilt, but found it limiting as coach parking is best east-west, getting on roof to tilt & lay down, and with the sun constantly moving there was no optimum position.  We later added more panels to compensate for not tilting.  We have seen diehards use a turntable to track the sun with tilted panels with a rope over the side of the coach.  There are also motor driven turntables that follow sun direction.
Title: Re: Solar Panel Install
Post by: Bob & Sue on September 21, 2023, 01:40:44 pm
They also make surface mounted panels.  And some manufacturers are using them.  Yes... I've heard the pros and cons.
  But, I've got a repair shop that uses them ( surface mount) and claims no problems yet. If I were to upgrade I'd be using them.
Title: Re: Solar Panel Install
Post by: Zach on September 21, 2023, 02:18:54 pm
How are you going to safely step off the coach ladder on to the roof?
I've heard this a few times in regard to my setup. Why does someone need to get onto the roof? Visual inspections can be done with a telescoping ladder around. The panels are semi-permanent, so any damage or sealing that needs to be done can be done following the removal of the panels. Most of the roof is covered, so cleaning isn't necessary. A simple hose down and brushing of the panels is all you need a couple of times a year at most.

My 5th wheel had a similar setup and used angle aluminum bolted to the bottom of the panel and another piece of angle on the roof. Never had an issue and didn't make them raised on the outside portion of the panel (they angled slightly to the edge of the roof). You really don't need a full length of angle aluminum and can just make some brackets. I'd use at least 1/8" thick aluminum.
Title: Re: Solar Panel Install
Post by: Dakota Slim on September 21, 2023, 03:02:22 pm
Why does someone need to get onto the roof?

To clean, service or replace the AC units? I suppose you could devise a way to walk across the panels without breaking them.
Title: Re: Solar Panel Install
Post by: fatheeler on September 21, 2023, 04:17:57 pm
I thought about that turning the panel across direction of travel with a 4 or 5" gap and making a step out of 2x10 with 5" legs
Title: Re: Solar Panel Install
Post by: Michelle on September 21, 2023, 06:18:44 pm
They also make surface mounted panels.  And some manufacturers are using them.  Yes... I've heard the pros and cons.
  But, I've got a repair shop that uses them ( surface mount) and claims no problems yet. If I were to upgrade I'd be using them.

Are you referring to flexible solar panels?  Many folks in the LTV group have had issues with them (they are installed as the OEM solar option) and have replaced them with rigid panels.
Title: Re: Solar Panel Install
Post by: Bob & Sue on September 21, 2023, 07:11:23 pm
Now I'm curious what the issues with flexible panels were.
  I assumed ( wrongly ? )technology was moving forward and problems were solved maybe not.

  Haven't talked to the repair guy since Covid , I'll have to see if he's had issues. Maybe it's the brand ?
Title: Re: Solar Panel Install
Post by: Barry & Cindy on September 21, 2023, 08:45:20 pm
Full length angle vs corner brackets: The inside roof beams are not usually located where the corners of the panel are located. Nothing more secure than screws into metal roof beams. And may not be best idea to drill new holes in solar panel frame to match roof beams.

Roof ladder: Service roof mounted air conditioner units, clean fiberglass roof to keep sides of coach clean. Painting roof will help keep fiberglass sealed. Clean solar panel glass. Safer way to climb onto roof than a ladder leaning against side of coach

How to tilt solar panels.

Your coach to maintain. There is no right solution. There is no real safe way to climb onto roof, including OEM ladder.
Title: Re: Solar Panel Install
Post by: Michelle on September 21, 2023, 08:59:09 pm
Now I'm curious what the issues with flexible panels were.


Significant overheating since there's no airflow on the underside.  Lowers output quite a bit from spec.  The overheating also has caused issues with the roof fiberglass. 

Bubbling/blistering/delam of the panels themselves, again due to heating.

Having to repair the roof after scraping the delaminated panels off.

They're easy for the shops that install them, not so much for the owners a couple of years down the road.
Title: Re: Solar Panel Install
Post by: Protech Racing on September 22, 2023, 01:26:56 pm
Things will stay cleaner and dryer if the water has a place to run off of the sides.  Full length VHB tape  should have some pass throughs for water escape.  IMHO.
Title: Re: Solar Panel Install
Post by: fatheeler on November 06, 2023, 03:25:13 pm
Finally got the panels mounted, I am planning on running wires down threw the frig vent there is a pipe that runs across the top of the cooling fins with little dimples in it does anyone know if this area gets to hot to run wire around it, also wondering about wind deflectors on front of panels to help with any kind of lift issues. The panels are held by 1" VHB 5962 with 3-M 4200 and 4000UV under and around the brackets, the brackets are also threw bolted on the outside and screwed into roof on the inside
Title: Re: Solar Panel Install
Post by: Zach on November 06, 2023, 05:35:15 pm
Similarly installed this way on my fifth wheel four years ago. Panels never moved. You shouldn't experience much, if any, lift with how low they are to the roof. Most wind is going to deflect off the nose and scatter at that height. If you do add deflectors, you're more likely to create noise associated with wind vibration.
Title: Re: Solar Panel Install
Post by: Elliott on November 06, 2023, 05:47:25 pm
I agree with Zach. Had similar on my 5er for three years without issue. Too many unknowns with aerodynamics to worry about it. Run it and move onto the next project.
Title: Re: Solar Panel Install
Post by: fatheeler on November 06, 2023, 06:04:01 pm
Thanks I will leave them at that,
Title: Re: Solar Panel Install
Post by: MarkC on November 06, 2023, 10:09:40 pm
Knowing very little about solar, I have a question.
Does installing the panels flat make that much difference compared to mounting at a slight angle following the roof curve?
Seems that as you never know the direction you'll be parked, you may never have perfect sun exposure therefore never getting 100% solar gain, and with the roof angle mounting you may get better gain on one side than the other?
Just curious.
Title: Re: Solar Panel Install
Post by: Chuck & Jeannie on November 06, 2023, 10:29:06 pm
When we had the solar panels mounted on our coach, I took the option of having them be "tilt-able".  In our case, to raise the panels I had to climb up on the roof, and (for each panel) loosen 4 wing nuts, remove two bolts, insert two aluminum prop rods, install four bolts, and tighten 6 wing nuts.  Then to lay them back down flat the same routine in reverse.  I did this a few times while we were boondocking for several days in one spot, but the chore soon became too much trouble to bother with.  After that, they just stayed flat.  I DO still tilt them up if I want to give the roof a good scrubbing, but that doesn't happen often...cuz I'm lazy.

Conventional wisdom says, if you really NEED the additional solar output that would be gained by tilting the panels, just add one more panel to your array.  The extra panel will do as much good as tilting the array, and it's a whole lot less work...plus safer (fewer trips up on the roof).
Title: Re: Solar Panel Install
Post by: Dakota Slim on September 02, 2024, 12:19:55 am
I thought there was a more recent post on this topic but couldn't find it so I'll bump this one.
My existing rigid panels (2 x 250 = 500 watts) are 8 years old and are only putting out about 7.5 amps when they used to produce twice that. One may have stopped working and as soon as it cools off I will climb up on the roof and see if I can test them individually but the wiring is under the panels and testing may require as much work as replacing them.
I am seeing some really low prices on flexible panels and wonder if anyone has installed the latest products. Michele mentioned people have had issues in the past but I'm wondering about what they are selling now. 
Title: Re: Solar Panel Install
Post by: Protech Racing on September 02, 2024, 03:39:53 pm
For 2 panels. Wire in series.  That way a failure is very noticeable.
Yes prices are way down.  I bought 370 watt panels for $200 new .
Title: Re: Solar Panel Install
Post by: steve on September 02, 2024, 06:34:01 pm
Which ones did you get?  I'm looking to replace the old panels on our coach.
Title: Re: Solar Panel Install
Post by: Protech Racing on September 02, 2024, 06:36:58 pm
Bought from Pedro in Deland Fl .
Not sure for brand today.  They put out so lid 30 plus amps in sets of 2 .
I will check but oot for 15 days. 
Title: Re: Solar Panel Install
Post by: Pierce & Gaylie Stewart on September 02, 2024, 07:11:40 pm
Our 4 x 285 watt panels are still going as strong as when we installed them back in 2008. They have taken a lot of falling tree branches without a problem. Midnite controller still working fine also. AGM batteries have a little less capacity but also 16+ years old. Panels are Yingli commercial left over from a big Mojave solar farm install. Nice to have more watts but getting rid of the OEM inverter and LED conversion now requires much less.

Pierce
Title: Re: Solar Panel Install
Post by: red tractor on September 02, 2024, 08:15:43 pm
Nice to see you back Pierce
Title: Re: Solar Panel Install
Post by: Pierce & Gaylie Stewart on September 02, 2024, 09:46:53 pm
Thanks! Long story with bad doctor, Covid, long covid with brain fade, new left hip (at UCSF) and being stuck in Budapest in a wheelchair but driving a stick shift rental car. Never every believe how good the airlines say the air is in the plane.

Pierce
Title: Re: Solar Panel Install
Post by: rbark on September 03, 2024, 02:01:26 am
Was wondering where you went Pierce! Glad your back also.
Title: Re: Solar Panel Install
Post by: TGordon on September 03, 2024, 07:07:28 pm
For 2 panels. Wire in series.  That way a failure is very noticeable.
Yes prices are way down.  I bought 370 watt panels for $200 new .
I bought 6, 540 watt panels from Solar Power Systems & Solar Energy Equipment - A1 Solar Store (https://a1solarstore.com/), they have pick up points all over the country, $192.00 each + the applicable state, local and galactic taxes. I picked mine up in San Diego, CA.

Tim
Title: Re: Solar Panel Install
Post by: Dakota Slim on September 03, 2024, 10:21:50 pm
I bought 6, 540 watt panels from Solar Power Systems & Solar Energy Equipment - A1 Solar Store (https://a1solarstore.com/), they have pick up points all over the country, $192.00 each + the applicable state, local and galactic taxes. I picked mine up in San Diego, CA.

Tim
Thanks for the link. Their prices and selection are great but it would be a long drive me. They will ship for $250 and up.
A group purchase might be in order.
Title: Re: Solar Panel Install
Post by: Caflashbob on September 04, 2024, 12:56:12 pm
My guru buddies personal safety assessment is that to not run high voltage off of an rv roof.  Danger to firemen in case of a fire. Hail damage?  Tree branch?  So i ran all three panels wiring with each  panel individually extensioned down off the roof at the refer vent location into the front storage bay then iacross and into  a midnight sun junction box that is capable of combining 6 panels positive and negative cables(i am only using 3 so far) then into a high capacity Magnum Energy PT-100 solar controller which is capable of 240 volt and 100 amps then into the Magnum 2812 inverter charger. The 365 watt LG neon panels maximum voltage is 39 volts. He was absolutely uninterested in doing any higher voltage work off of the rv's roof.  May need to be in conduit if combined on the rv roof?  Codes?  Old rv roof panels were only in the mid to high 20's in voltage per panel for a reason it seems.

My understanding is that firemen will not approach an rv on fire with a large PV roof installation for the fear of the possible high voltage.  There maybe insurance issues if high voltage violates codes?

The higher wattage panels may put out high enough voltage individually to be a concern?  Were not made for rv use.  Residential or commercial.  Be safe is my concern as was my guru buddy. [irrelevant comment removed - Michelle]
Title: Re: Solar Panel Install
Post by: Dakota Slim on September 04, 2024, 03:11:54 pm
I thought there was a more recent post on this topic but couldn't find it so I'll bump this one.
My existing rigid panels (2 x 250 = 500 watts) are 8 years old and are only putting out about 7.5 amps when they used to produce twice that. One may have stopped working and as soon as it cools off I will climb up on the roof and see if I can test them individually but the wiring is under the panels and testing may require as much work as replacing them.
I am seeing some really low prices on flexible panels and wonder if anyone has installed the latest products. Michele mentioned people have had issues in the past but I'm wondering about what they are selling now.
Well, I climbed up on the roof early this morning (when it was only 85 degrees) and found that my panels were filthy and there were some large matted globs of salt cedar needles and seeds on one of my panels. I got out the hose and cleaned them up as well as what was on the rest of the roof. It's high noon now and they are putting out 16 amps.
Title: Re: Solar Panel Install
Post by: Michelle on September 04, 2024, 03:26:52 pm
Codes?  Old rv roof panels were only in the mid to high 20's in voltage per panel for a reason it seems.

More because of the technology at the time. 

As for codes, RVIA has the following  Product - Community Hub (https://my.rvia.org/NC__Product?id=a1B2M00000H1sklUAB)

Best to research for yourself as technology and guidance changes constantly and what may have been the case years ago no longer applies.

I can't imagine any RV fire where a firefighter is going to get up on the roof of the RV, thus worrying about them not responding to or fighting a fire because of the voltage of panels on the roof is complete and utter fear-mongering. 

There are residential codes regarding panels on fixed structures needing disconnects, which may delay respondents getting on the roof of a building until those disconnects are thrown, but again, that doesn't apply in the case of an RV fire.  RV fires are fought from the ground or a bucket truck, not the roof of an RV.
Title: Re: Solar Panel Install
Post by: Pierce & Gaylie Stewart on September 04, 2024, 04:52:29 pm
Michelle has it right on. As a retired fire fighter, our first priority is lives. While fiberglass does not burn, the resin that bonds it together plus all the thin wood used in construction make for a fire that spreads not in minutes but seconds. When we roll up to a RV fire in a park, the first thing is to check that everone including pets is out. Most of the time it's way too late as the fire is well established and protecting other RVs and structures is next with water applied to the burning coach done after we secured a water supply. An RV fire on the street us usually fought with the first engine using tank water to put the fire out.

Lithium battery fires are the most difficult as they may require  a huge amount of water minimize the spread to surrounding areas. Last month, a Tesla trailerless semi with only lithium engine batteries crashed on I-80 and shut the interstate down for all night and part of the next day because of the toxic smoke. Last night, also only a few miles from us, only a couple of lithium batteries (72 lbs total) caught fire in a sealed railroad freight car destroying the entire car and damageing the next inline fright car. Tesla story: A Tesla Semi crashed and caught fire on a California highway - The Verge (https://www.theverge.com/2024/8/20/24224576/tesla-semi-crash-fire-highway-california-i-80)

If you have an RV fire, the very first thing to do is get everyone out as quickly as possible and then call 911. Trying to go back in to save any personal belonging may be fatal as many in RVs, aircraft and homes have found.

Pierce