Is this solar setup a bad idea?

[kckyle]

I leave my TT parked in the woods on my farm. I eventually plan to build a cabin out there. I dont have electricity so I want to get some solar panels and batteries set up to provide additional power. My idea is to build a pretty decent size setup and house my batteries, inverter, charger, etc in a small shed near my tt and just have a 30amp outlet on the outside I can plug my TT into. This way I don't have to modify my electrical system on the trailer and when I build the cabin I can continue using that same setup for the cabin. I'm thinking as far as the trailer goes it would be just like I was plugged into shore power? What do you think? will this work like I think it will?

[dutchmensport]

I've always said, "Anything is possible if you have enough time, talent, equipment, space, and money." What you would like to do is do-able, but at what cost? A portable generator with an adequate fuel supply tank would be much easier.

[flybouy]

Originally Posted by kckyle

I leave my TT parked in the woods on my farm. I eventually plan to build a cabin out there. I dont have electricity so I want to get some solar panels and batteries set up to provide additional power. My idea is to build a pretty decent size setup and house my batteries, inverter, charger, etc in a small shed near my tt and just have a 30amp outlet on the outside I can plug my TT into. This way I don't have to modify my electrical system on the trailer and when I build the cabin I can continue using that same setup for the cabin. I'm thinking as far as the trailer goes it would be just like I was plugged into shore power? What do you think? will this work like I think it will?

Solar panels won't work in the woods. You need an unobstructed view of the sky. The panels ideally should be tilted perpendicular with the sun.

[JRTJH]

There is a thread current active on "large solar systems". One member posted photos of his system and stated that he ran the trailer air conditioner for 5 hours and still had 30% of his available battery charge available. That means to me, that he probably could run his air conditioner for around 7 to 8 hours before he had no available power. https://www.keystoneforums.com/forum...ad.php?t=50119

Cost to do that? According to that member, parts were around $14,000 and labor was another $3,800. That's roughly $18,000 to be able to run the trailer with air conditioning for 8 hours.

Comparing, a Champion 3200 watt inverter generator costs about $600 and will run 5-8 hours on a gallon of gas. Using this system, even at the end of that 8 hours, with another gallon of fuel, you can keep the air conditioner running "indefinitely".

Doing some "off the wall math", at $3 a gallon and getting 5 hours per gallon, I figure you could buy and run that champion generator for around 29,000 hours and still have enough money left over to buy a new generator if you wore that one out.... BTW, 29000 hours is roughly 3 years and 4 months.

[GHen]

I’ll agree with above comments, if you don’t have very good sunlight, buy a generator.

If the TT is in the shade and If your shed has full sun, you could do the setup like you describe. Since you will lose efficiency by running power through and inverter, put a quick disconnect on a battery in the shed. When you arrive take a charged battery from the shed and put it in the TT. Rotate as needed. Just need to cut some trees down.
I would also completely disconnect the battery in the trailer each time you leave or it could be dead/damaged from parasitic devices using power, when you return, turn it back on.
If the shed solar will be covered with snow for a while in winter, I would also disconnect those batteries, better yet, take them home.

Summary, cut a bunch of trees down or buy a generator.

[snoobler]

Originally Posted by kckyle

I leave my TT parked in the woods on my farm. I eventually plan to build a cabin out there. I dont have electricity so I want to get some solar panels and batteries set up to provide additional power. My idea is to build a pretty decent size setup and house my batteries, inverter, charger, etc in a small shed near my tt and just have a 30amp outlet on the outside I can plug my TT into. This way I don't have to modify my electrical system on the trailer and when I build the cabin I can continue using that same setup for the cabin. I'm thinking as far as the trailer goes it would be just like I was plugged into shore power? What do you think? will this work like I think it will?

This is what I have done, except the shed is a 40' shipping container in glorious AZ sun with 3kW of solar on it (fixed tilt for optimal year-round performance), 12kWh of T-1275 4S2P (48V, 250Ah), a 4kW inverter and 50A RV pedestal outside the container. The pedestal is actually wired with L1/L2 shorted since my inverter is only 120VAC.

I already have the hardware for the following upgrades:

50kWh Lithium battery
A second invterter that can operate parallel with the other to provide 120/240VAC split phase.

I power two 5th wheels, obviously at reduced capability due to 4kW absolute continuous power limit, and it's literally like they're plugged into shore power. Neither 5th wheel is modified.

I can run ONE A/C for about 8 hours without dipping into the battery.

Originally Posted by flybouy

Solar panels won't work in the woods. You need an unobstructed view of the sky. The panels ideally should be tilted perpendicular with the sun.

This. I harvest a large number of photons from sunrise to sunset since most of my "trees" are the 10-15' juniper "bushes" and the occasional 20' pinon pine. I also benefit from 6500' elevation. Thinner atmosphere means more sun to the panels.

Shaded panels perform horribly compared to their ratings. You really need to assess how much solar you can harvest and how the change in the sun's position throughout the year impacts it.

[kckyle]

wow thank you for all of the replies and sorry I left out some key details.

My trailer is just 80ft down a hill north of a large pasture where I would place the panels so there is plenty of sunshine available.

I have a nice 30amp Inverter generator that will run 24 hours on a standard propane tank. Its great generator and pretty quiet but my goal is to have some silent power.

I want to be able to wake up and have the use of my coffee maker, microwave, tv, etc but still be able to look out and see some deer, coyote, turkey and other wildlife without a loud generator scaring them off.

I was thinking to size my systems such that I could run the basics for quite a while and even run the AC for a bit but also connect the generator to the system so I can fire it up as needed. I have seen these all in one inverter chargers that allow you to connect your solar panels and your generator so that when your batteries are low you can fire up the generator and the generator will power your load and help recharge the batteries at the same time.

I'm trying to find the sweet spot where I spend the right amount on solar to mainly cover the basics so Im not wasting a bunch of money on extra solar I hardly ever use but also have enough solar that I'm not constantly running the generator.

It sounds like snoobler has a setup very similar to what I'm thinking. That makes me feel better that someone else had the same idea and it seems to be working well. Since I'm only looking to run 30amp and a couple hours of AC I think my system could be quite a bit smaller although I will size my inverter charger such that I have the ability to expand the panels and batteries as needed.

I'm think something like this all in one inverter charger which basically acts as a UPS https://watts247.com/product/lv6548-...built-in-wifi/

with 1000w of panels and 48v 100ah battery to start.

[German Shepherd Guy]

Totally doable.I have lived off of the grid now for over 40 years. As John said though a system as big as mine would run 18,000 at today's prices. Mine was less than 1/2 that but I have also added to it through the years. Mine is over4kw. I run a full size house and shop (some large machinery as I ran a knifemaking business and a blacksmith shop) and can produce 220 ac. I do it where we have well over 240 days a year of good sun at 8,000 ft elevation.
My monthly "electric bill" has now averaged out at less then $30 per month. And I am beholden to no electric co-op.



If I was starting over I would add in a wind generator, which in your area seems like it would make a lot of sense.
Go online check your local area. There are lots of folks now who make their living installing solar systems. They would know your area and what the requirements in batteries and panels would be for a system to do what you want.
Listening to generators sucks. Sometimes it is the only way but with your wanting a cabin there I would go with the solar/wind option if possible.

Good luck.

[roadglide]

Originally Posted by kckyle

I leave my TT parked in the woods on my farm. I eventually plan to build a cabin out there. I dont have electricity so I want to get some solar panels and batteries set up to provide additional power. My idea is to build a pretty decent size setup and house my batteries, inverter, charger, etc in a small shed near my tt and just have a 30amp outlet on the outside I can plug my TT into. This way I don't have to modify my electrical system on the trailer and when I build the cabin I can continue using that same setup for the cabin. I'm thinking as far as the trailer goes it would be just like I was plugged into shore power? What do you think? will this work like I think it will?

I like the idea running the cabin from solar. There is no reason to modify your rv ele system for solar . The only place I connected to was the panel breakers underneath the refrigerator my system isn’t connected to the converter. I have 70 amp controller charger that takes care of the batteries. The inverter is connected to the breakers switches for the camper . My system has a relay coming from the inverter automatically switch over when the generator or shore power is on.

[snoobler]

Originally Posted by kckyle

wow thank you for all of the replies and sorry I left out some key details.

My trailer is just 80ft down a hill north of a large pasture where I would place the panels so there is plenty of sunshine available.

I have a nice 30amp Inverter generator that will run 24 hours on a standard propane tank. Its great generator and pretty quiet but my goal is to have some silent power.

I want to be able to wake up and have the use of my coffee maker, microwave, tv, etc but still be able to look out and see some deer, coyote, turkey and other wildlife without a loud generator scaring them off.

I was thinking to size my systems such that I could run the basics for quite a while and even run the AC for a bit but also connect the generator to the system so I can fire it up as needed. I have seen these all in one inverter chargers that allow you to connect your solar panels and your generator so that when your batteries are low you can fire up the generator and the generator will power your load and help recharge the batteries at the same time.

I'm trying to find the sweet spot where I spend the right amount on solar to mainly cover the basics so Im not wasting a bunch of money on extra solar I hardly ever use but also have enough solar that I'm not constantly running the generator.

It sounds like snoobler has a setup very similar to what I'm thinking. That makes me feel better that someone else had the same idea and it seems to be working well. Since I'm only looking to run 30amp and a couple hours of AC I think my system could be quite a bit smaller although I will size my inverter charger such that I have the ability to expand the panels and batteries as needed.

I'm think something like this all in one inverter charger which basically acts as a UPS https://watts247.com/product/lv6548-...built-in-wifi/

with 1000w of panels and 48v 100ah battery to start.

Make a list that has:

What you want to power, how many watts, how many hours, W * h = Wh.

Sum all the Wh.

That's the amount of battery you need
That's used to determine how much solar you'll need based on your location and available solar.

NOT a fan of MPP Solar/Growatt units. What's not obvious with the particular unit you linked is that it's a power hungry monster by itself. Even if powering no loads, it will burn 100W continuously.

You will need the equivalent of a a 12V, 400Ah lead-acid battery (48V, 100Ah) just to have it turned on, even if you don't use any loads at all - not even a single LED light.

Additionally, the 250Voc/18A PV input limits on the MPPTs make it essentially impossible to get 4000W out of an attached array. 3000W is the practical limit.

My 5kVA inverter uses 27W and has an excellent true surge capability of 10,000VA. Even with A/C, microwave and other loads, I've never overloaded it. I could if I started maxing out the loads on the 2nd 5th wheel, but it's more like a spare bedroom now.

You should use the list I mentioned above in sizing the inverter. Given that you have a 30A/120V system, you shouldn't be looking much beyond 3000W.

Define the need, satisfy the need.

Concerning solar, at less than $0.50/kW, PV is often the cheaper part of the system. Batteries are what kill you. It's a pretty common practice to skimp a bit on battery for extra PV when you know you can use your power hungry items at peak solar and never have to worry about using that power at night.

You can save even more on solar by buying quality used panels from some place like SanTan Solar.

EDIT: If you plan to use the same system on your future cabin, you need to basically design the end system and then figure out how to piecemeal it.

[bbells]

Yes, it will work. I have 3 solar setups on my hobby farm. A 27kwh grid tie in. A 5kwh offgrid system on a trailer with 800ah in batteries (barn). On my shed I have 1.5kwh with 200ah batteries. Oh, my camper has 1.5kwh with a 200 amp 12v battery. All were designed by figuring out my useage first, then deciding on battery and panel size. That is the only way to do it. With the camper you can either do the math, or you can plug in a "Kill a Watt" meter when hooked to a regular 120v extension cord and adapter for the trailer. And record the numbers for a day or so. Same deal for the cabin. Home refrigerators/freezers take a lot of power. AC takes way more than most solar systems can handle - You would need a very large battery bank (3000wx24hrs=72kwh). You would be better off running a generator when using AC. But, if you switch to led lights the usual stuff would not take too much power. Lights, stereo, TV, even the microwave is ok for short periods of time.