7x14ft Trailer + 1.8kW Roof Array

[Casteil]

Looking for some constructive criticism around some plans for a solar trailer setup to collect/store power and feed it into a transfer switch in my house for 6 select circuits to offset a good portion of my consumption, so if you're interested in seeing what I've already planned/ordered - carry on, and thanks!

Main Components

• 7x14ft enclosed cargo trailer, 7ft interior height with a 'v-wedge' front, rear double doors & side 'rv' style entry door
• 4x 455W SolarEver half cell mono perc panels from SanTan (+1 'just in case', could be hung down the side of the trailer in future for auxiliary 12V LFE setup permanent to trailer)
• 1x 5.1kWh LifePower4 rackmount battery bank from Signature Solar
• 1x Growatt SPF 3000TL-LVM-48P inverter from Signature Solar
• 1x Reliant Pro/Trans2 6 slot transfer switch for code-approved feed into house circuits (non grid tied)

Design

• 4x 455W Array mounted on rails a few inches over roof, hinged on driver's side to tilt for angle to sun (possibly both sides if I can figure out a convenient system/design for that with easy/secure stowing for travel)
• PV entry gland, feeding inside to location for Inverter + Battery (likely in front wedge area)
• Semi-portable case for inverter + battery, able to hang on wall with a French cleat, or possibly moved inside for extreme weather
• 'Shore power box' - 'in-use' weather box with 120V 15A inlet, and outlets for 120V AC output (NEMA 5-20 feeding into a generator transfer switch), and switchable PV output (~110V DC / 16A - if extreme temps require running inverter + battery inside)
• 1" rigid foam insulation (R5) for trailer walls/ceiling to try to help regulate interior temps in extreme conditions

Added Benefits / Functions

• Mobile Trailer / Workshop / 'Toy Hauler' with Solar & 120V AC portable power system/battery storage onboard (expandable) to use on rural property
• Possible camper if more time/money put into interior
• If I move, my solar setup comes with me without a fuss

Many other considerations, but these are the main ones. This will sit in my driveway for its first couple years probably (receiving improvements), collecting/feeding power into some of my more continuous 120V AC circuits. My average consumption for the whole house is only ~400W continuous on a typical day (or a total of about 10kWh), so demand from these circuits isn't crazy. I also won't be backing up AC and/or stove usage with this system unless/until I get a second inverter to parallel along with another LifePower4.. but my 20A fridge circuit feeds a couple extra outlets that I could run things like the toaster oven or other cooking devices in a pinch.

Trailer will look something like this, but lighter in color to keep it cooler in summer:

 

[JoeHam]

Someone on the forum just did a build almost exactly like this.

I think it’s a great way to proceed.

Hopefully my second cup of coffee will help me find it for you ?.

 

[Casteil]

Someone on the forum just did a build almost exactly like this.

I think it’s a great way to proceed.

Hopefully my second cup of coffee will help me find it for you ?.

Was it this one? Just had a gander at it last night as I was posting this ?

I suppose a couple things I'm seeking specific input on are:

1. Options for an 'in use' weather box for 'shore power' and PV DC + 120V output
2. Hinging ideas for the roof mount panels to be able to hinge from both sides, or lock securely for transit
3. Any glaring flaws or concerns more seasoned solar gurus may recognize with this setup

 

[JoeHam]

No it was a utility trailer setup to plug into a house or outbuilding like yours.

It had two 16s DIY 280Ah batteries mounted on the right side as you look in from the back and an AIO inverter/MPPT on the wall. I think he was using an RV style plug for the power connection through the wall.

I cannot recall if the solar panels were going to be flat mounted on the roof or ground mounted next to it.

Sorry I can’t find the thread yet or be more help.

 

[JoeHam]

Still can’t find it but here’s one YouTube idea for panels :

 

[Casteil]

Still can’t find it but here’s one YouTube idea for panels :

Hadn't seen that one yet. That'd be a much cheaper trailer though, it's ~$10k for the all-aluminum frame trailer I'm thinking about. Guy makes a lot of points I'd had as considerations, too (e.g. the fact that I can just slap this Growatt 3000 + LFE battery into a cabin for power later).

Their use of aluminum tubes for hinges & sleeved supports is pretty slick. I might have to consider that.

I mocked this idea up for my 'hinges' yesterday evening, basically holes drilled/bushed in the ends of the unistrut (colored orange), using clevis pins for pivots, with the ability to lock it all down for transport (the clevis pins would also be used to secure the panel-tilt prop arms to the trailer then the panel array) -


Might have to break the array into two pieces that can hinge separately so I don't have to try to simultaneously lift, prop up & pin support for 200+ pounds worth of panels 9ft+ off the ground. So yeah, that prop for the panels using the sleeved tube sounds kind of nice..

 

[Odom1957]

You could use a linear actuator to lift the panels, then you wouldn't need to lift them by hand. Also, you could use linked linear actuators to lift multiple panels simultaneously with multiple actuators. You will have to allow for a little space under the panels for the actuators to sit, but not a lot.

 

[Casteil]

You could use a linear actuator to lift the panels, then you wouldn't need to lift them by hand. Also, you could use linked linear actuators to lift multiple panels simultaneously with multiple actuators. You will have to allow for a little space under the panels for the actuators to sit, but not a lot.

Not a bad idea - will keep that in mind. I already anticipate keeping the panels elevated off the roof a little anyway (mostly for snow/ice considerations), so fitting a linear actuator or two in is definitely possible.
...would definitely need some additional consideration/design though, especially if I still want the panels to be able to hinge off either side of the roof.

Also - received my panels from SanTan today & everything appears to be in good shape (nice looking/feeling panels)! Unable to test yet though; haven't seen the sun since last Sunday, and it might be another week if we don't get a brief glimpse tomorrow afternoon.

 

[Heyjimmy911]

I kept the roof static and use tilt only the side panel. The side panel also acts like an awning. I make enough power to run my a/c all day, a small freezer, a fridge/freezer, lights, microwave, cappuccino machine, toaster oven etc. I guess what I'm saying is you may not need the extra power associated with he tilt roof. I used sun power 327w commercial panels because they felt sturdier and they fit edge to edge. I went overboard with nuts and bolts as well as additional aluminum reinforcement along the edges of the panels.

If you do engineer a roof tilt, please do share. I've been thinking about it for a few years.

 

[JoeHam]

Nicely done Jimmy !

Love those sliding glass doors.

 

[Casteil]

I kept the roof static and use tilt only the side panel. The side panel also acts like an awning. I make enough power to run my a/c all day, a small freezer, a fridge/freezer, lights, microwave, cappuccino machine, toaster oven etc. I guess what I'm saying is you may not need the extra power associated with he tilt roof. I used sun power 327w commercial panels because they felt sturdier and they fit edge to edge. I went overboard with nuts and bolts as well as additional aluminum reinforcement along the edges of the panels.

If you do engineer a roof tilt, please do share. I've been thinking about it for a few years.

Nice setup! I'm probably going to do a slight overhang over the back double doors for a little bit of cover. But just like your setup, I could fit two along the 14ft length of the trailer for a total of 2.7kW. In hindsight, I really should've ordered a 6th panel.

We'll have pretty comparable wattage though (~2275W) if I end up putting my 5th panel on the side. I'll definitely keep this thread updated. Roof panel tilt would be mostly for winter - I'm at a relatively high latitude so my winter sun stays pretty low in the sky.

 

[Odom1957]

There are calculators online that show you how to mount actuators to allow for a certain tilt angle, and most importantly, show you the force required, based on weight.

The only advice I can give you from my experience is to attach the top of the actuator away from the hinge. This requires less force to lift than the opposite direction, allowing for a more compact setup.