Autie retro tech geek!

Solar Powered Class-A RV

MK and I have been discussing this dream for many years and it’s finally going to happen. Our health problems make winter painful, so we’re going to follow the warmth.

We’re going to snowbird in a 40ft diesel pusher, and I’m going to cover it with solar panels. My career is as a solar designer, both grid-tie and off-grid, with experience designing both tiny systems and up to half a meg.

The plan is to put ~12kWh of batteries in the “basement”, with a 6.8kW 48v inverter, and 2.56kW of solar on the roof. I will plug the shore cord into the on-board power plant to avoid modifying any RV electrical systems. The Schneider XW6848 hybrid inverter will have a plug to go to the actual shore power when available.

Other immediate planned additions include a 4-camera security camera system, cellular Internet + WiFi, and 32TB media archive.  Future plans include composting toilet and remove black tank to add a second freshwater tank.

All of this, of course, will be documented thoroughly in this blog.

March 23, 2019: The Bus Comes Home

2008 Damon Astoria Pacific Edition with 20k miles


It has 3 slides, two opposing in the front and a smaller one for the bedroom.

Wasn’t long before I was on the roof, with a cardboard template matching the SolarWorld XL modules’ footprint

Here’s how I’m going to pull this off.  I’m putting 8 SolarWorld 320w XL modules on the roof (those are the big ones 37.8″x78.46″ typically used on commercial arrays).  They will be tied to the Schneider 60-150 charge controller in 4 parallel strings of two, which feeds a 12kWh bank of lithium iron phosphate batteries at 48vdc (4 250aH 12v units in series).  This powers a Schneider XW6848 6.8kW inverter, which will have a 50a receptacle so that the RV shore cord can be plugged directly into it.  Therefore, the RV’s electrical systems remain unmodified; the RV simply thinks it’s always plugged into the grid, even while going down the highway.

I will also have a new 120/240 50a shore cord on the input side of the inverter for plugging into campsites if needed, as well as a transformer to take 30a or 15a 120vac inputs as well (since the inverter is a split phase 120/240 unit, it needs 240vac input).  The beauty of this inverter is that I can limit the maximum power it pulls from grid, so even with a measly 15a 120v hookup, the system will pull from solar/batteries + grid as needed and never exceed what I tell it to.

There may be one minor modification made to the RV electrical, that is easily reversed should we want to sell and upgrade.  I may pull the generator’s output from the RV’s transfer switch and connect it to the generator input on the inverter.  Should there be bad weather for many days and we’re off-grid, I can then turn it on and charge the batteries in a couple of hours, then turn it off again, thus enjoying silence once again and barely using any diesel.

March 26, 2019: Procuring Equipment

I’ve purchased the panels and mounting brackets, and put in an order for the inverter.  I will be ordering the 4 250aH 12v lithium batteries soon.  I also have 12v deep-cycle GEL batteries to replace the existing flooded coach batteries with.  I refuse to have batteries onboard that need watering or that vent hydrogen.

March 27, 2019: Batteries and inverter ordered, just have to wait for all the components to start landing here in Hagerstown, MD!  Batteries expected to land here beginning of May from overseas.  Since we’re going to run off-grid (boondock) often, I need to make this rig more efficient.  Therefore high priority was to replace every single incandescent light bulb I could find with LEDs

March 28, 2019: My friend Jesse came over and switched out the batteries for me.  Out with the 4 flooded 6v GC-2 and in with the 3 GEL Group 27s.  The RV loses about 100 lbs and 100aH BUT these batteries will be constantly floated by the solar system so I didn’t need as much lead in there.  I may even take one out at some point to further lighten the load.

April 02, 2019: New LED fixtures for the ceiling came today.  These will replace the old-skool fluorescent fixtures currently in the bus.

April 04, 2019: Equipment has landed…just waiting on the batteries!