Expedition Duo: "Freedom" the RV Goes Solar

"Freedom" the RV Goes Solar - Phase II

This is the second in a series of blog posts about adding solar to our RV "Freedom". If you haven't seen the "Phase I" post, check it out here:

"Freedom" the RV Goes Solar - Phase I

The Plan

After doing some research, power calculations and taking some measurements of the available space on the roof of the RV, we decided we would start with multiple solar panels totaling 800 watts. We think there is enough space available for a total of about 1400 - 1800 watts on the roof if future expansion is needed, but we think 800 watts will be sufficient to run the necessities for short periods of time while boondocking.

We will be using Renogy 100 watt panels due to cost per watt and space configuration on the roof. We will also be using aluminum strut channel for mounting the solar panels to allow for future configuration changes and to allow us to put as few holes as possible in the roof. Due to the fact that our RV roof is made up of Styrofoam sandwiched between two thin sheets of wood panel with a PVC rubber roofing membrane, it will be necessary to screw the strut channels to the metal cross members of the roof. By utilizing the strut channel, we will be able to use fewer screws placed into the cross members, rather than needing to put multiple screws into the roof for each panel.

The eight solar panels will be connected in two groups of 2P x 2S. Each group will have it's own breaker and charge controller.

Phase II: Equipment Needed

For Phase II, we'll be adding the solar panels to the roof of the RV, adding a junction box (with terminal block) on the roof to connect the solar panels, installing the wiring from the junction box to the equipment compartment inside, installing breakers for the solar panels, and installing the solar charge controllers. Let's get started...

List of the major equipment necessary for Phase II:

8 - Renogy 100 Watt solar panels
1 - Weatherproof Junction Box
1 - 10 Gang Terminal Block
4 - 10 AWG Solar Y Connectors
2 - 10 AWG Solar Extension Cables (1x20ft., 1x10ft.)
1 - Circuit Breaker Box
2 - Circuit Breakers
2 - Victron SmartSolar MPPT 100 | 30 Charge Controllers
50 ft. of 10 AWG wire

Phase II: Equipment Installation

The first part of our solar panel installation was to determine a suitable location to have the wiring enter the roof of the RV. We decided to have the wiring enter the roof directly above the rear of the refrigerator. This location was fairly easy to access (by removing the fridge), and it also provided access to a route for the wire to reach the equipment compartment located in the bedroom by following the existing duct and water pipes running from under the cabinets in the kitchen and through the back wall of the bathroom.

We started by removing the refrigerator and locating the place for the 2" hole through the roof, being careful not to hit any of the cross members. Next, Mark nervously drilled the hole through the roof.

Next, we placed a piece of 2" PVC through the hole and sealed it into place using LAP Sealant. The purpose of the 2" pipe is to make it easier to run the wires, and to also make it easy to cap off in the future if need be.

Next, a 2" hole was drilled into the bottom of the junction box, and the box placed over the pipe. LAP Sealant was used to seal around the pipe inside and out, as well as around the edge of the box where it contacts the roof. A small hole was drilled into the pipe, and a block of wood and screwdriver used to hold it in place until the LAP sealant dried.

Mark had prepared the junction box with cable glands and the terminal block ahead of time, so that it wouldn't be necessary to mount these after the box was in place.

After the LAP sealant dried, the wires were ran down behind the refrigerator, to the floor, and back to the equipment compartment in the bedroom. The solar breakers and charge controllers were installed in the equipment compartment, and 10 AWG wiring used to make the connections to the existing Lynx Distributor.

(insert pictures of breakers and charge controllers here)

The next step was to install the solar panels on the roof. We began by installing strut channel screwed to the roof cross members with stainless screws, and using LAP sealant around every screw. Next, we installed the solar panels to the strut channel using stainless hardware. Finally, the solar panels were wired together in two sets of 2P x 2S and connected to the junction box.