Solar system with RV - integrated vs modular

[mrfusi0n]

I have a fifth-wheel RV trailer my family is using as a semi-permanent home. We will not be traveling in it nor do we plan to move it any time soon. Stock, it has two 12v lead acid marine batteries and a gasoline generator. Next to the RV we have a 20' shipping container we are using for storage. My plan is to fill the top of the shipping container with solar panels and have the inverter, charge controller, battery, etc. inside the container. I've sized the solar system on the larger side with up to 5kw of pv (won't all fit on the container), up to 6kw inverters (3kw growatt x2), and a 10kwh 48v lifepo4 battery bank.

Finally, my question is, should I integrate the solar into the existing RV systems or keep things more modular and wire the solar to the RV "pretending" it is shore power. The RV expects a 4-wire, 50amp plug (split phase). I can't give it 12kw but I could still give it 6kw which is more than enough for our needs.

I like how clean the modular approach would be since the RV is not modified but it might be a waste of the generator since it wouldn't charge the solar batteries without additional wiring. Also, the RV 12v systems would be powered via AC instead of the more efficient 48v to 12v DC/DC conversion (maybe that doesn't really matter).

My last thought is that in a few years, we may build a small home or tiny home and would use this solar system for that instead of (or in addition to) the RV.

 

[DerpsyDoodler]

Finally, my question is, should I integrate the solar into the existing RV systems or keep things more modular and wire the solar to the RV "pretending" it is shore power. The RV expects a 4-wire, 50amp plug (split phase). I can't give it 12kw but I could still give it 6kw which is more than enough for our needs.

Wiring up a 50 amp (or 30 amp, there are dog bones you can use to plug a 30a source into a 50a plug) outlet seems like the most simple (KISS) and practical. It keeps your options open “just in case”. I don’t know what the codes or ordinances are like where you live or if you could be forced to move your tt, at some point. Are you making it a permanent structure? (Taking off its wheels and putting it on blocks?

 

[mrfusi0n]

Wiring up a 50 amp (or 30 amp, there are dog bones you can use to plug a 30a source into a 50a plug) outlet seems like the most simple (KISS) and practical. It keeps your options open “just in case”. I don’t know what the codes or ordinances are like where you live or if you could be forced to move your tt, at some point. Are you making it a permanent structure? (Taking off its wheels and putting it on blocks?

Thanks for the reply!
I'm in a fairly remote part of Hawaii so I don't think codes and ordinances are much of an issue at least for now. I do want to keep things as safe and straightforward as possible, though.
A couple things I forgot to mention before are that the solar will be about 50' from the RV. Also, I could do split phase with the two Growatts but I'm thinking of combining the two hots since nothing needs 240v and I'd like the full 6kw available on either side/phase. I think that makes sense and is safe... right? ?

I'm leaning towards keeping it simple as you suggested. It may not be the most efficient but optimization is usually best left for "phase 2" (assuming "phase 1" is simple and makes sense). Thanks again!

 

[snoobler]

I have a fifth-wheel RV trailer my family is using as a semi-permanent home. We will not be traveling in it nor do we plan to move it any time soon. Stock, it has two 12v lead acid marine batteries and a gasoline generator. Next to the RV we have a 20' shipping container we are using for storage. My plan is to fill the top of the shipping container with solar panels and have the inverter, charge controller, battery, etc. inside the container. I've sized the solar system on the larger side with up to 5kw of pv (won't all fit on the container), up to 6kw inverters (3kw growatt x2), and a 10kwh 48v lifepo4 battery bank.

Finally, my question is, should I integrate the solar into the existing RV systems or keep things more modular and wire the solar to the RV "pretending" it is shore power. The RV expects a 4-wire, 50amp plug (split phase). I can't give it 12kw but I could still give it 6kw which is more than enough for our needs.

That's what we did.

My 40' shipping container has the panels on top and equipment inside. I have the inverter output out the wall of the container into conduit to a 50A RV power plug.

The container is about 40' from the closest 5th wheel (we have two), and the receptacle is about 30' from the container. I use a few of the 30' big 50A extension cables and splitters to get everything hooked up.

This is an aerial from 5/2020:



The Northernmost unit is a motorhome. That has left and been replaced by another 5th wheel forming about a 60° angle with the original 5th wheel.

You can see 3 of the 9 solar panels that are now installed. Have another 9 to go. The two big white dots are 275-330gallon totes for water storage.

Recent pic from totes looking back at container/power pole/panels:

 

[DerpsyDoodler]

just to note, I’m not an electrician. if by “combining the two hots” you mean wire up a 240v split phase outlet, that’s entirely up to you and your wants/needs. I’ll be wiring a 50 amp shore inlet for my rv. 1 leg will go through disconnect to inverter, other leg will go through disconnect and into its own side of my ac main, while my inverter will feed the other side of that box. This means I could effectively wire 240 split phase outlets for when I’m on shore power, but I see no need. I have a generator that will do 240 split phase (just not at the full 12k) for the very rare occasion I may actually need it; but if/when I ever find myself wishing I had it, it’s just a wire run and outlet installation away (when connected to shore, anyway). And if I ever need it on the road, then I’ll look at investing in an inverter(s) capable of it.

 

[snoobler]

I currently have L1 and L2 shorted. Once I get the second Quattro online and working with the first in parallel 120/240VAC split phase, I'll revert to standard wiring.

 

[snoobler]

Fresh pic from the Blink cam:



Panels:



Mascot:

 

[mrfusi0n]

Very helpful, guys! Thanks so much!
Great setup, snoobler!
I'll report back once I get stuff setup. Hopefully in a few weeks...

 

[chrisski]

With the amount of power you’re talking, it’d be hard not to use the Shipping container.

I have a 12 volt system with 4 golf cart batteries, and with wiring, SCC, Inverters, busbars, that takes up half of the pass through storage under the master boardroom.

Another reason I like the shipping container idea, is the metal roof on the container is much more secure mounting the panels to the roof with tilt mounts than the tilt mounts I have on the RV. When I tilt the panels onthe RV, I can get 40% more production, but not sure how secure they would be in a huge gust.

I really do like @snoobler ’s system.

 

[snoobler]

My "racks" are technically adjustable... I just don't bother. When I see 80% rated output in December, I lose all motivation to mess with it.