whole roof solar

[LarryD]

just got a quote for a 3.2 kw whole roof solar panel system.... Any one have any experience with anything similar?

[Lt Keefer]

How do you clean the A/C units on a rig like that? Or inspect the sealant? How many of those attachment points will leak in a good downpour? How do you get up there to clean the panels? Too many questions for me to do something like that.

[Chateau_Nomad]

Experience... as in using a system of this size, or experience having a system like this installed?

If investing that much, I'd consider a track system where each bank of panels could be either slid or tilted to access the other roof components - A/C, vents etc.

Each bank (half) could slide sideways into a "use position" when parked, then slide back to center and lock for travel.

[LarryD]

@Lt Keefer the panels are detachable but you do have to mind the trellis/frame system. Should go a long way toward protecting the roof and a/c I'd imagine.

[LarryD]

@Chateau Nomad mostly around any concerns, especially with travel worthiness.

[ducksface]

The concern is
Value.
If you have a generator or an alternator or are camped in a cushy park, as shown in that picture,
Solar has exactly
ZERO value.

It's a fine hobby.
A small panel is a precious thing to have for batteries when storing away from shore power.
Otherwise
The only value is boondocking IF you don't have an alternator or generator.

I had a system about half that size on a 19ft toyhauler with a xantrex 3000 and all the solar toys.
No alternator, boondocking, and ran the heater and fridge at night in quiet, no shore power places.
My v10 is quiet enough no one can here it from 10 feet away.

Too much
'Hey! Look at me!'
In that system.

Not.even.if.it.were.free.

[LarryD]

Originally Posted by ducksface

The concern is
Value.
If you have a generator or an alternator or are camped in a cushy park, as shown in that picture,
Solar has exactly
ZERO value.

It's a fine hobby.
A small panel is a precious thing to have for batteries when storing away from shore power.
Otherwise
The only value is boondocking IF you don't have an alternator or generator.

I had a system about half that size on a 19ft toyhauler with a xantrex 3000 and all the solar toys.
No alternator, boondocking, and ran the heater and fridge at night in quiet, no shore power places.
My v10 is quiet enough no one can here it from 10 feet away.

Too much
'Hey! Look at me!'
In that system.

Not.even.if.it.were.free.

understood and agree. ROI is also nothing. But value is subjective. including 1kwh lithium batteries the system is nearly 30k. So whats that almost 30k buy me? It buys me the ability to boondock on the sand at beaches where generators are not allowed to be run. It allows me to give my wife multi million dollar views from waterfront property @ Race Point in MA, Montauk on LI in NY and countless other places here in Fl. In short, the value of that ~$30k is saving me millions of dollars. Seems pretty valuable to me.

[Chance]

Originally Posted by LarryD

understood and agree. ROI is also nothing. But value is subjective. including 1kwh lithium batteries the system is nearly 30k. So whats that almost 30k buy me? It buys me the ability to boondock on the sand at beaches where generators are not allowed to be run. It allows me to give my wife multi million dollar views from waterfront property @ Race Point in MA, Montauk on LI in NY and countless other places here in Fl. In short, the value of that ~$30k is saving me millions of dollars. Seems pretty valuable to me.

A system with 3,200 Watts of solar capacity could make 10 kWh of energy on a sunny day, and maybe up to 15 kWh if parked in south or desert in summer. You need a lot more than 1 kWh of lithium battery to start with, depending on what you plan to accomplish.

There are a lot of technical issues that need attention, but energy storage to be useful is one that’s at top of list. Can you describe how you plan to use this system?

[LarryD]

sorry, 1000. its actually 3x 330 victron batteries. plan is for coach to be 100% off grid, running a/c all day etc. most of these places allow you to run your gen for a few hours durring the day to top off as needed.

[LarryD]

Originally Posted by Chance

A system with 3,200 Watts of solar capacity could make 10 kWh of energy on a sunny day, and maybe up to 15 kWh if parked in south or desert in summer. You need a lot more than 1 kWh of lithium battery to start with, depending on what you plan to accomplish.

There are a lot of technical issues that need attention, but energy storage to be useful is one that’s at top of list. Can you describe how you plan to use this system?

3 of these for 1010ah @$3k ea

https://rvsolarconnections.com/shop/...thium-battery/

[Dan-sr@perra-us.net]

Originally Posted by LarryD

just got a quote for a 3.2 kw whole roof solar panel system.... Any one have any experience with anything similar?

What are those struts attached to? I wonder how whether the roof structure would be able to hold the fasters while withstanding the lift generated by all that wing area going down the highway at 70 mph into the 30-mph headwind? Actually, I am sure the fasteners will hold what I am not sure of is will the roof withstand the lift forces trying to pull the fasteners out.

Kind of resembles stuffing a Ford 427 V8 onto a British sports car... No wait someone has already done that. See the Schelby Cobra. NO wait most of those were intended as race cars and barely street legal in the 60's.

Just because you can do something doesn't mean it is wise or prudent.

[ducksface]

At 6'4" I've always been jealous of guys 5'7".
The myriad of cars they can drive that I look like a clown in....

Look up Bill Cosby Cobra.

[MLP]

Looks like all the inspection points for attachment are on the outer edges. The panels are quite high so cleaning could be done. A lot of money, but if your happy and going to use them for years to come...

[dkoldman]

Wow... double wow. I have zero experience with this. I have zero solar and don't even want to put a panel up to charge batteries. Mainly because I don't need to.

I have 250ah effective 125ah (50%)

You would have 990ah effective 792ah (80%)


So for $30k you can go 6 times longer than I under same conditions assuming I am restricted from using my Genny. Wow!!! But if you are running AC off batteries, I can't replicate that, but you will draw that 6 times longer number to a number a lot smaller.

If you buy, I wish you well. Stick with your priorities. Doesn't seem like cost is factor for you.

My wife and I do kind of what you are saying you want to do a lot but it is not in million dollar value areas. We have State and Camp passes to various lakes that we drive our RV to and just park next to the water, not always a campsite so we boondock. We may be there all day. Sometimes from the inside it looks as if we are in a boat on the water. We runs TVs and AC all day. I get Gennys may not be optimum, but we are never that close to anyone where a Genny can't be run.

[Chance]

Originally Posted by LarryD

3 of these for 1010ah @$3k ea

https://rvsolarconnections.com/shop/...thium-battery/

OK, that’s more like what I’d expect as a bare minimum. Energy storage is just over 12 kWh, so maybe 10 kWh maximum useable. That’s roughly one day’s worth of solar production.

A large motorhome parked in sun will need two air conditioners, and that will require close to 3,000 Watts in middle of day (assuming efficient rooftop units).

Worst-case scenario being that generators are not allowed, you should expect +/- 3 hours of cooling in middle of day before batteries are depleted.

If generators are allowed an hour or two in morning and then again at night, it changes everything because focus should then be to charge batteries as fast as possible, and that’s a different problem altogether.

A solar system similar to what you describe if intended for boondocking makes most sense to me to power one of the two air conditioners at night to sleep comfortably, then have solar recharge batteries during day for the next night.

If your goal is to air condition 24 hours a day without relying on generators, the numbers just don’t work out beyond maybe the first day.

Major concern is that 16 X 200-Watt panels will weigh at least 400 pounds, plus supports, etc. You will add at least 500 pounds on roof, or equivalent of 6 typical RV rooftop air conditioners. This will affect motorhome handling by increasing center of gravity.

Another concern is that roof structures where they span slide openings are not made to support that much weight.

In my professional opinion to make something like this work well would require designing a motorhome from the onset for the intended and specific boondocking application. Retrofitting technology usually ends up costing way too much for what’s gained, and often falls short on performance. It’s a very common problem IMO. As example, I found a van camper that I like floor plan and most of the design and build quality, so went to factory a couple of weeks ago to see how they are built. Unfortunately, to upgrade for boondocking like I want, it would take a ton of money, work and time. It’s technically possible, but jury is out on whether it makes much sense to try upgrading.

[Jimbo56]

Originally Posted by Dan-sr@perra-us.net

What are those struts attached to? I wonder how whether the roof structure would be able to hold the fasters while withstanding the lift generated by all that wing area going down the highway at 70 mph into the 30-mph headwind? Actually, I am sure the fasteners will hold what I am not sure of is will the roof withstand the lift forces trying to pull the fasteners out.

Kind of resembles stuffing a Ford 427 V8 onto a British sports car... No wait someone has already done that. See the Schelby Cobra. NO wait most of those were intended as race cars and barely street legal in the 60's.

Just because you can do something doesn't mean it is wise or prudent.

My thoughts as well. Of course, maybe a convertible motor coach might be a sight to see. Just don’t be behind it when it peels off. I wouldn’t trust Thor to have used enough screws to hold it down.

[LarryD]

Originally Posted by Jimbo56

My thoughts as well. Of course, maybe a convertible motor coach might be a sight to see. Just don’t be behind it when it peels off. I wouldn’t trust Thor to have used enough screws to hold it down.

I'd think downforce would be more likely than lift. Might help with the high speed cornering....

[dkoldman]

Originally Posted by Jimbo56

My thoughts as well. Of course, maybe a convertible motor coach might be a sight to see. Just don’t be behind it when it peels off. I wouldn’t trust Thor to have used enough screws to hold it down.

Did you you ask to see Convertible RV

No Solar in it either. Not recommended in areas with lots of dust or falling leaves, even with a Leaf Blower.

[LarryD]

Originally Posted by Chance

OK, that’s more like what I’d expect as a bare minimum. Energy storage is just over 12 kWh, so maybe 10 kWh maximum useable. That’s roughly one day’s worth of solar production.

A large motorhome parked in sun will need two air conditioners, and that will require close to 3,000 Watts in middle of day (assuming efficient rooftop units).

Worst-case scenario being that generators are not allowed, you should expect +/- 3 hours of cooling in middle of day before batteries are depleted.

If generators are allowed an hour or two in morning and then again at night, it changes everything because focus should then be to charge batteries as fast as possible, and that’s a different problem altogether.

A solar system similar to what you describe if intended for boondocking makes most sense to me to power one of the two air conditioners at night to sleep comfortably, then have solar recharge batteries during day for the next night.

If your goal is to air condition 24 hours a day without relying on generators, the numbers just don’t work out beyond maybe the first day.

Major concern is that 16 X 200-Watt panels will weigh at least 400 pounds, plus supports, etc. You will add at least 500 pounds on roof, or equivalent of 6 typical RV rooftop air conditioners. This will affect motorhome handling by increasing center of gravity.

Another concern is that roof structures where they span slide openings are not made to support that much weight.

In my professional opinion to make something like this work well would require designing a motorhome from the onset for the intended and specific boondocking application. Retrofitting technology usually ends up costing way too much for what’s gained, and often falls short on performance. It’s a very common problem IMO. As example, I found a van camper that I like floor plan and most of the design and build quality, so went to factory a couple of weeks ago to see how they are built. Unfortunately, to upgrade for boondocking like I want, it would take a ton of money, work and time. It’s technically possible, but jury is out on whether it makes much sense to try upgrading.

thank you for the response. I had not considered the weight on the roofs impact to the rigs center of gravity. Will noodle on it but not sure it'll be significant enough to matter for me. Its 8x405 panels btw if that matters. If I narrow down my use cases I come to two "most common" scenarios. 1. is a 12hr day at the beach, RV parked in a waterfront lot or road without power. 2nd is a week on the sand where we'd have to run the generator for some period each day. I think in both cases the system makes a significant impact on our enjoyment. I agree its not perfect but is the highest improvement for $ spent I can come up with.

[Chateau_Nomad]

The Achilles heel of RV solar/battery power sources is air conditioning. Everything else is manageable, but when you add the massive amperage requirements of traditional compressor powered cooling units - coupled with the extremely poor R-value of an RV, all bets are off.

Scrap the A/C and it's quite possible to comfortably do with half the batteries and solar. But if you MUST have A/C, better invest in a ground based solar farm and semi-trailer packed with battery storage to travel with you.

Otherwise, just fire up the generator, sit back and relax.