YES: RV Solar/ Li/ and AC running full time

Very interesting idea! I think on my next build I'm going to do sliding panels out from the roof, so it's like a solid solar awning. Yeah.

I would kill to find a solar panel that can actually roll up into a 2-3" Radius. Then line the awning with them and roll them up when done!! Anybody know if it exists?

Lt.Dan said:

I would kill to find a solar panel that can actually roll up into a 2-3" Radius. Then line the awning with them and roll them up when done!! Anybody know if it exists?

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I have thought of that myself but have not seen any yet. also thought about flex panels on the outer end of the awning just install eyelets inline with the panel eyelets for attachment but not sure how good it would be if the wind picked up

Lt.Dan said:

I would kill to find a solar panel that can actually roll up into a 2-3" Radius. Then line the awning with them and roll them up when done!! Anybody know if it exists?

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You and me both. But you know someone, someday will figure out how to make an ultraflexible cell.

This looks like a pretty good deal. The footprint is a bit bigger than what I'm looking for, but the other numbers looks pretty good.

K8MEJ said:

This is good advice, especially if you have plenty of room on both sides of your camper at your camp spot. I did something different, though. I made solar awnings to use when the driver side of my TT is exposed to the sun. They don't look pretty, but they add another 300 watts (realistically 220 watts is the most I've ever seen them make when wired in series) but most importantly they help keep the windows on that side of the RV cool without having to lower the shades and put reflectix behind the shade.

I got the idea from the RV with Tito DIY RV channel on YouTube. I made some slight changes but it's essentially his idea. They can also be ground mounted if you need the extra solar but don't need to shade the windows.

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That's a good idea, I watch his channel too.

Lt.Dan said:

I would kill to find a solar panel that can actually roll up into a 2-3" Radius. Then line the awning with them and roll them up when done!! Anybody know if it exists?

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Maybe 10" radius. https://www.recycledgoods.com/solar-panels/?sort=featured&page=1&mode=4

Zwy said:

Maybe 10" radius. https://www.recycledgoods.com/solar-panels/?sort=featured&page=1&mode=4

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Wow! Only 136w and its that large of a footprint? It must have terrible efficiency.

And MC3 connectors?? Lol

Lt.Dan said:

Wow! Only 136w and its that large of a footprint? It must have terrible efficiency.

And MC3 connectors?? Lol

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There are other panels than just the 136w, some without any connector.

I checked just about every one, didn't see anything smaller than 8 inch diameter rolled up. https://www.recycledgoods.com/iland...e-solar-panel-battery-charging-solder-points/ Most of these are the most flexible panels I know of, designed for military use.

Wow it takes a lot of solar to keep up with ac, being conservative keeping thermostat 78-82 it takes 2000 watts of solar to have the extra head room for water pump ,hot water heater ect. and we have had some mild heat here 100-102 days and 70's at night . I don't think I will give up the genset or roof air just yet

Lt.Dan said:

I fully believe the 13.5k and 15k BTU rooftop AC's are not performing at their rating, or at the very least are loosing a lot of cooling capabilities due to ducting inefficiencies etc. I have 3x 15k BTU rooftop AC's and they struggle to keep the trailer at 80* when its 105-115* outside. With 45k BTU's, I'd expect it to easily maintain 70*. I also think this is why lower BTU mini splits and window AC's are capable of doing the same thing as my 3x rooftop AC's.

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I've wondered the same thing given the excellent performance @Generis is getting. I don't have ducting but it seems my unit shouldn't be struggling as much as it does for such a small space (and I use heavy blackout curtains between the cab and the main living area).

The efficiency of an AC unit will have a huge impact on the electrical load, that is for sure. Never doubt how many little things you can do to drop the solar heat load. Having a blanket cutting off the cab will not only make a heat barrier but also mean your cooling does not have to enter the cab area, and that's less cubic feet of air to cool. Heat load or not you're making your unit actually smaller to cool. That will also have huge impact on your electrical load over time.

In the last few days we've had another nice heatwave over here in Ontario Canada. I traveled in the RV south about 300 miles and discovered daytime temperatures of around 98 in full sun and around 78 at night. With this new heatwave, I discovered my heat pump has a middle mode!

As described earlier in my thread here, I do know that if I use the turbo button on the remote the compressor and fans will go into some kind of high gear and really crank out the cold air. Of course the watt load will suffer because of this, but it certainly can do it. This last weekend in the 98° sun I found out that the unit has some kind of middle gear, where if it needs more power to do maintenance it doesn't go from low to turbo, it has a very slightly different tone somewhere in the middle line. I'm calling it middle gear.

The heat was enough that the unit decided it was time to kick on the middle gear, and that produced around a 60 amp continuous DC draw through my electrical system. As we are slightly waning off of the solar high, my solar production was around 700 Watts and the heat pump was consuming all of it. I found that to be an interesting change of events although, it was incredibly hot and remains that way still today. No wind. No relief.

So with the "on" consumption being 700 watts, instead of the usual 400, my average went up quite a bit to something closer to 600 watts an hour. Of course that is the reading during the hot daytime hours. The result was around 170 amp hour reduction in battery (out of 500+ ah available) over the evening hours, and a little bit slower recharge during the day, because the consumption was higher than my normal.

I did come up with a fairly simple solution for my heavy electrical load, I simply change the thermostat. I usually leave it at around 72, and I bumped it up to 74 which was enough to certainly have a comfortable living space, but also eliminate a bunch of electrical load. Not very hard to manage, but a simple temperature change was all that was needed. This was a very interesting experiment!

Always learning as we go.

Update:
Finally got the Dicor EPDM coating on the roof yesterday, which was phase 2 of this project. Phase 1 was scraping off the old Dicor self-leveling sealant (23 years old!) around all the roof openings and applying new sealant.

I feel like I got it on just in time. One more year and I think I would have had to replace the roof due to sun damage.

Not me in the pic; got the help of a local RV tech to do the work at his house because I'm in a park currently (don't want to run the risk of being banned using caustic chemicals near other campers) and every shop is booked until the end of October.

The Rig in the Plastic Bubble™:




Using the power washer to remove the cleaner/activator and dirt. In Phase 1 I also got rid of the forward vent because it's going to get covered by solar panels anyway.




Two gallons gave me two thick coats and a third thin coat. The cleaning and application all have to be done on the same day.



I also got the use of a 2000psi power washer for two hours and I swear it took 10 years off my rig. Gonna have to get me one of those (like this 1,800 psi model at Home Depot). It's sparkly clean though I have a fair amount of recaulking to do now. Still completely worth it, though. The pollution had gotten caked into the caulking and in all the crevices; the power washer dislodged grime I would not have been able to with just a rag and garden hose.



Next steps:
• install the the mini-split heat pump
• remove the roof air conditioner (to make space for the four residential ~325W solar panels)
• install the solar panels
• enjoy a margarita

Next stop is Utah where I'll go check out Camping World's first "Electric World" location. Camping World was aiming to release an electric RV with Lordstown Motors but since that entity has declared bankruptcy who knows how they will pivot.

Generis said:

Never doubt how many little things you can do to drop the solar heat load.

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Definitely. I'm also anticipating that covering my roof with solar panels will help reduce insolation dramatically.

74 degrees is acceptable though I expect with your extra panel you'll have all the power you'll need for a lower indoor temperature and higher outdoor temperatures.

The update on the 9,000 BTU Senville in 90+ days is very useful; interesting to hear that it's not working hard with those temperatures. Still, near Vegas it reaches 115+ and a visit to Death Valley can get there and beyond. (Though why one would want to visit Death Valley in the summer is beyond me. Saline Hot Springs for Thanksgiving is my favorite time to go.)

@Generis, can we convince you to visit Nevada to perform some high temperature testing there, too?

For all of you running these alternate air conditioners from your batteries, please if you can, turn off your solar panels so that you can report actual draw in different conditions.

Thanks,

My battery bank increased capacity is in place. So I’m getting closer

richard cabesa said:

For all of you running these alternate air conditioners from your batteries, please if you can, turn off your solar panels so that you can report actual draw in different conditions.

Thanks,

My battery bank increased capacity is in place. So I’m getting closer

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What help is that? Turning off the charge?
If I've got a 38a charge and a 24a draw isn't that still 60 amps? If I've got a 25 amp charge and zero consumption or charge on the meter, isn't that still a 25a load?

The roof looks good, Mine has aluminum roof and it gets hot enough to cook on. Ambient temps make all the difference. Have had a cool down here for a few days mid 90's and the little 8000 btu window ac was working great sipped power compared to 105f . I think what I am going to do is run a 5000 btu window ac for mild days and the solar can keep up fine with it then for the extreme hot days run the gen set with roof air

Thanks, Tazmann. It turned out well. It's a very thick acrylic liquid that's easy to apply. When I was looking for a shop with a bay to do the work, one of the places I called told me they don't do recoatings anymore because they find "they don't last long." After working with it, I'm doubtful of that comment but I shall soon find out. (Maybe they wanted to upsell me and replace the whole roof?)

I'm sure you could be a short-order chef with an aluminum roof.

Your hybrid approach will work fine, I'm guessing. Running a generator sporadically is very different from having to run it all the time. I'm going to be two weeks at Bonneville Salt Flats and I'll learn firsthand what running a generator all the time will be like...

Curious to know the consumption in kwh for a 24 hour period in various conditions.

My biggest issue with this is most RVs tend to have horrible insulation. Going from half an inch to 1 inch for example is night and day in my estimations for power needs.

One of these years I want to build something that will run an A/C off battery for at least 72 hours, and I think that's easily done with R10 all the way around in a 16 foot trailer. That's 2" of xps foam for context.

richard cabesa said:

For all of you running these alternate air conditioners from your batteries, please if you can, turn off your solar panels so that you can report actual draw in different conditions.

Thanks,

My battery bank increased capacity is in place. So I’m getting closer

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It would be better to utilize a shunt on the ac circuit. That might not be a bad idea actually, it allows for calculation of expected draw to battery power seperate from the main shunt.