Most "how much solar do I need" guides give you one formula and expect it to apply whether you're towing a 17-foot teardrop or driving a 40-foot Class A. It doesn't. Roof space, typical daily power draw, and towing/payload constraints are different enough by RV type that the right starting point looks different for each one. Here's a breakdown by category, with realistic targets rather than best-case marketing numbers.
Camper Vans & Class B Motorhomes
Van roofs are compact and usually shared with a roof rack, fan, and sometimes a pop-top mechanism — real usable solar space typically tops out around 400W even on a full-size cargo van chassis. The upside is that van-life power draw tends to be modest: LED lighting, a 12V compressor fridge, laptop charging, and occasionally a small induction cooktop or espresso machine.
| Typical Setup | Target Range |
|---|---|
| Solar array | 200–400W (roof-limited) |
| Battery bank | 100–200Ah lithium |
| Inverter | 1,000–2,000W pure sine |
Our van life solar setup guide covers the full build in more depth, including where to route wiring through a van's tighter cavity space.
Travel Trailers (20–30 ft)
This is the largest RV category on the road, and roof space is generally good — a single AC unit, a couple of vents, and an antenna still leave meaningful open area. The constraint here is usually tow vehicle payload and trailer tongue weight more than roof space, especially if you're also carrying a large battery bank.
| Typical Setup | Target Range |
|---|---|
| Solar array | 400–600W |
| Battery bank | 200–300Ah lithium (or 300–400Ah AGM) |
| Inverter | 2,000–3,000W pure sine |
If your travel trailer roof has an odd layout around the AC and vents, see our guide on fitting solar around obstructed roof space before assuming you're capped lower than you actually are.
Fifth Wheels
Fifth wheels typically have the largest usable roof area of any towable RV, split across the main body and the raised front "gooseneck" section. That upper deck is often shaded less and easier to keep clear of obstructions, making it a strong spot for a dedicated array.
| Typical Setup | Target Range |
|---|---|
| Solar array | 600–800W+ |
| Battery bank | 300–500Ah lithium |
| Inverter | 3,000W pure sine |
Because the pin weight sits over the tow vehicle's bed rather than a rear hitch, fifth wheels generally tolerate a larger battery bank without the same tongue-weight concerns travel trailer owners face. That's part of why fifth wheel owners tend to run larger lithium banks than trailer owners of similar length.
Class C Motorhomes
Class C roofs are long but often narrower than a fifth wheel's, and typically carry one or two AC units plus the cab-over bunk structure at the front, which usually isn't usable for panels. Expect a similar array size to a travel trailer, with power draw sometimes higher due to onboard generators and larger appliance loads common in this class.
| Typical Setup | Target Range |
|---|---|
| Solar array | 400–600W |
| Battery bank | 200–400Ah lithium |
| Inverter | 2,000–3,000W pure sine |
Class A Motorhomes
The largest roofs on the road, often with 2+ AC units and correspondingly higher baseline power draw (residential-style fridges, multiple slide-outs, sometimes washer/dryer combos). Many newer Class A models ship with factory-installed solar as standard equipment, reflecting how much this category has shifted toward expecting solar rather than treating it as an aftermarket add-on.
| Typical Setup | Target Range |
|---|---|
| Solar array | 600–1,000W+ |
| Battery bank | 400–800Ah lithium |
| Inverter | 3,000–3,500W+ pure sine |
Start from your actual power draw, not just RV type
These ranges are starting points. Run your real appliance list through our sizing calculator to get a number specific to how you actually camp, then compare kit options sized to match.
The One Thing That Matters More Than RV Type
How you camp changes these numbers more than what you drive. A Class A owner who mostly stays at RV parks with shore power needs a fraction of the solar a van-lifer boondocking full-time needs, regardless of roof size. Use the ranges above as a ceiling based on available space, and your actual usage pattern — covered in our battery pairing guide — to decide where within that range to land.