Flexible solar panels are among the easiest ways to add power to an RV roof. There’s no rack, no tilt bracket and, with the right adhesive, very few holes. Renogy’s current solar panel installation manual sets out a specific recipe for gluing flexible modules to a roof. It covers silicone bead width, spacing, which edges to leave open, and a 72-hour cure. This guide walks through those steps in order, then adds the wiring, bending limits and heat notes RV owners need before they climb the ladder.
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The video above is my test of the BougeRV Arch Pro 200W flexible panel, the panel I use as the example below. The Arch Pro 200W is on Amazon.
Before you start: three roof checks
- Roof material. RV roofs are usually EPDM rubber, TPO, fiberglass or aluminum. Whatever silicone, tape or sealant you use has to be compatible with that surface. Check your RV maker’s roof guidance before buying adhesive.
- Flat or ribbed? Renogy uses different methods for flat roofs and non-flat (corrugated) roofs. On a non-flat roof, the panel needs to sit on at least six silicone lines across its back. If it can’t, Renogy says the panel isn’t suitable for that roof.
- Open space. Measure between vents, the AC shroud, antennas and skylights. A 200W Arch Pro is 53 x 31 inches, according to BougeRV. Leave walking room around fixtures so you can service them later.
Tools and materials
| Item | Why you need it |
|---|---|
| Flexible panel(s) | The panels themselves |
| Roof-compatible silicone structural adhesive | Renogy’s recommended bonding method for flexible modules |
| Double-sided mounting tape | Holds the panel in place while the silicone cures |
| Primer (if your adhesive maker calls for it) | Renogy’s flexible-panel guideline shows a 3M primer step |
| Cleaner (e.g., isopropyl alcohol) and lint-free rags | Bonding surfaces must be free of dirt and residue |
| Hand roller or pressing tool | Renogy calls for light, even pressure along each bead |
| Roof cable-entry gland and lap sealant | To bring the wires inside and seal the hole |
| Solar extension cable (10 or 12 AWG) with MC4 ends | Renogy’s inter-module and controller cables use 10/12AWG |
| Charge controller or power station with a solar input | To turn panel output into battery charge |
Step-by-step: flat RV roof
These steps follow section 5.3.1 of Renogy’s installation manual. Where a number comes from Renogy, I’ve said so.
- Plan the layout. Lay the panels out, still in their packaging, and mark the corners with painter’s tape. Renogy’s diagrams show panels with either the long side or the short side facing the direction of travel. Pick whichever fits around your vents. Leave 5–10 mm between neighboring panels (Renogy).
- Carry it flat. Renogy’s guideline warns that carrying a flexible panel unevenly can crack cells and reduce output. Support it along its length with two people.
- Clean both surfaces. Remove dirt and old residue from the roof and from the back of the panel. Renogy says this is what gives a strong bond between the backsheet and the roof. Let everything dry completely.
- Prime if required. Renogy’s guideline shows a primer step and says to let it sit for 2–3 minutes after applying. Follow your adhesive’s own instructions here.
- Apply tape to the short edges. Put double-sided tape along each short edge of the panel’s back, as flush with the edge as you can.
- Run the silicone beads. Lay lines of silicone along the length of the panel, 6–10 mm wide and 3–5 mm thick, with about 10 mm between lines (Renogy). The gaps let heat escape and water drain.
- Place it within five minutes. Renogy says the panel has to go down within 5 minutes, before the silicone starts to cure.
- Press evenly. Roll lightly along the bonded areas, in the same direction as the beads. Use even pressure across the panel, never point pressure, which can damage cells.
- Leave the short edges open. Renogy’s manual says not to seal all four sides. Leave at least the short edges unsealed for heat dissipation and drainage, and to avoid the risk of fire.
- Let it cure for 72 hours. Renogy says to leave it 72 hours for the silicone to fully cure, out of direct sun, rain and bad weather. Don’t drive until it has cured.
A note on Renogy’s older guideline
Renogy has an older one-page “Flexible Panel Installation Guideline” (written for its DB-H series) that you may still find online. It said to bead silicone around all four edges with no gaps (at least 10 mm wide and 4 mm thick), add adhesive bars every 30 cm, and fully seal the windward edge so wind and rain can’t get underneath.
The current manual changes that advice. It leaves the short edges open for cooling and drainage. I’d follow the current manual and whatever your own panel’s manual says. If they conflict, contact the panel maker before you glue anything.
Corrugated or ribbed roofs
On non-flat roofs, Renogy’s method (section 5.3.2) differs in three ways:
- Tape goes on each long edge, not the short ones.
- Silicone is applied to match the width of the roof’s raised ribs, with at least six lines across the panel’s back.
- Once the silicone is done, you can add bolts through the panel’s own mounting holes for extra hold.
The same rules apply: place the panel within 5 minutes, press lightly along the glue lines, and leave 5–10 mm between panels.
How much can you bend it?
Flexible panels bend, but how much you bend them during installation affects output. Here’s what the makers say:
| Source | Maximum bend | Installation guidance |
|---|---|---|
| Renogy manual | 240° (for storage) | Mount flat, or with less than a 30° bend. Never more than 30° when bending across a short edge. |
| Renogy manual | n/a | Past 30°, more than 30% of the panel is no longer directly lit, which cuts output. |
| BougeRV Arch Pro 200W | Up to 270° | Designed for curved RV roofs and boats |
| BougeRV Yuma 200W CIGS | 360° | Can be rolled up |
On a gently crowned fiberglass roof you’re well inside these limits. On a sharply curved teardrop or Airstream-style roof, check the arc before you buy. A narrower panel may follow the curve better than a wide one.
The peel-and-stick option
Some panels come with adhesive already on the back. BougeRV’s Yuma 200W adhesive version is one example. BougeRV says it sticks to any smooth surface with no drilling. A punched version with corner grommets is also available for screws or brackets.
BougeRV’s FAQ gives three upkeep tips for adhesive panels:
- Clean the panel with a soft, damp, non-abrasive cloth.
- If you remove a panel, take any residue off the roof with industrial alcohol.
- Replace the adhesive backing if gaps start to form between the panel and the roof.
I compare those two BougeRV panels in BougeRV Arch vs Yuma CIGS 200W.
Getting the wires inside
Most installs run the cables through a roof cable-entry gland near the panels, then down to the controller through a cabinet or the fridge vent.
Renogy’s manual says to protect cables from mechanical damage, sun and rain, and to keep bends no tighter than a 43 mm radius. Seal the gland with a sealant that’s compatible with your roof.
Keep the run short and the wire thick. My voltage drop calculator guide and wire gauge chart cover the sizing.
Series or parallel? Check the voltage
Renogy’s manual explains the basics. In series, voltages add and current stays the same. In parallel, currents add and voltage stays the same. Renogy also advises against mixing panel models or brands in one string.
Using BougeRV’s Arch Pro numbers (Voc 36.4V, Isc 6.7A):
| Wiring | Open-circuit voltage (STC) | Current |
|---|---|---|
| 1 panel | 36.4V | 6.7A |
| 2 in series | 72.8V | 6.7A |
| 2 in parallel | 36.4V | 13.4A |
Voltage rises in cold weather. Renogy gives a correction formula based on the panel’s Voc temperature coefficient. With the Arch Pro’s -0.3%/K, a 14°F (-10°C) morning raises Voc by about 10.5%. That puts two in series at roughly 80V (estimate).
Confirm that your controller or power station’s solar input can take that voltage before wiring in series. If it can’t, wire in parallel. For a controller option, see my SunSwift 60A MPPT review.
Heat and shade: what to expect
Glued-down panels run warmer than rack-mounted ones because there’s no airflow underneath. Renogy’s FAQ puts output loss at 0.3–0.5% for every 1°C above 25°C. So a panel running 30°C hotter than that baseline produces roughly 9–15% less power (estimate).
The open short edges and gaps between beads in Renogy’s current method help a little. Expect summer output below the label rating.
Shade is the other factor. Renogy’s FAQ describes its flexible panels as two vertical halves. Shading most of one half cuts output by only about 10%, but shading both halves, even slightly, drops output almost to zero. Keep panels clear of the AC shroud’s afternoon shadow.
For more on panel ratings, see solar panel specs explained. Weighing flexible against rigid? My flexible vs rigid solar panels for RVs and vans guide covers the trade-offs.
Upkeep
Check the beads and the cable gland each spring and after long trips. Clean the panels gently. My CLEANTITE cleaner review shows how I clean my flexible panel. Don’t walk on panels unless the maker says they’re walkable. BougeRV says its CIGS panels are walkable.
For smaller vehicles, see my car roof mounting guide for flexible panels.
FAQ
What adhesive should I use for flexible solar panels on an RV roof?
Renogy recommends silicone structural adhesive, plus double-sided tape to hold the panel during curing. The adhesive must also be compatible with your roof membrane, so check your RV maker’s guidance.
Should I seal all four edges?
Renogy’s current manual says no. Leave at least the short edges unsealed for heat dissipation and drainage. An older Renogy guideline said to seal all four edges, so follow your own panel’s manual.
How long before I can drive?
Renogy says to let the silicone cure for 72 hours, out of direct sun and rain.
Can I screw flexible panels down?
Many have grommets or mounting holes. Renogy’s non-flat roof method adds bolts through those holes after the silicone. Every roof penetration needs sealing.
How much can a flexible panel bend once installed?
Renogy recommends less than 30° for best output. Its panels bend to 240° for storage only.
Bottom line
A flexible-panel roof install is a weekend job if you follow the maker’s recipe. In short:
- Clean everything.
- Tape the edges and run 6–10 mm silicone beads with gaps.
- Place the panel within five minutes and press it evenly.
- Leave the short edges open and give it 72 hours to cure.
Get the wiring voltage right for your controller, and your RV will charge silently all day with almost nothing on the roof to catch the wind.