Solar PV systems involve high-voltage DC and substantial fault currents. Improper installation can cause fire, injury, or death. Consult a licensed electrician and your local Authority Having Jurisdiction (AHJ) before any installation work, and verify every value against the current NEC edition and current product datasheets. Numbers and recommendations on this page are educational starting points, not a substitute for professional design and inspection.
RV / motorhome
Solar setup for an RV
RV solar splits into two completely different problems: boondocking without AC (1–2 kWh/day, easy to solve), and boondocking with AC (5–8 kWh/day, expensive to solve). Here's the build for each.
Typical RV load profile (no AC)
- RV absorption fridge on DC — 30W avg, 24h → 720 Wh
- Lighting — 40W, 4h → 160 Wh
- Water pump intermittent → 150 Wh
- TV/entertainment — 100W, 3h → 300 Wh
- Phone/laptop charging → 200 Wh
- Furnace fan (propane heat) — 100W, 6h → 600 Wh
Total: ~2 kWh/day for typical no-AC boondocking. Add an AC unit running 4 hours a day and you're at 6–8 kWh/day.
Recommended build — no AC
Recommended build — with AC use
Why these numbers
12V for no-AC builds stays compatible with existing RV electrical (lights, fridge, water pump, furnace are usually 12V native). Don't overcomplicate.
24V for AC-capable builds because 3 kW continuous inverter draw at 12V is 250A — wires get thumb-thick and connections get hot. 24V halves every current number.
Soft-start on the AC unit is non-negotiable. A 13,500 BTU rooftop AC has a startup surge of 4,500W+ for half a second — your 3,000W inverter will refuse to start it. A MicroAir EasyStart cuts the surge to ~1,800W. ~$300 component that makes the entire build possible.
Real-world gotchas
- Roof real estate. Many Class C and travel trailers can fit 400–600W on the roof; large Class A's can fit 1,200W+. Measure first.
- Tilt-up brackets. RVs parked for weeks in one spot benefit enormously from tilting panels south at 20–30°. Real-world: 30%+ more production through fall and winter.
- DC-DC charger. Almost everyone running LFP in an RV adds a 30–60A DC-DC charger that pulls from the alternator while driving. Adds another 1–2 kWh/day of charging capacity for free.
- Skip the converter, keep the inverter/charger. A modern inverter/charger (Victron MultiPlus, Renogy Pro) does the converter's job plus 50A shore-power passthrough. Cleaner install than two separate units.