How many solar panels for a camper van?
About 4 panels at 100 watts, roughly 400 watts on the roof, for a camper van that draws 1.2 kWh (1,200 Wh) a day at national-average sun. Desert sun trims it to 3; cloudy country needs 4. In bigger 200-watt panels that is about 2. Where the 1,200 Wh comes from, and how the count moves with your sun, are both below.
The 12V loads that add up to 1,200 Wh
A van build runs lean by design: LED everything, one efficient compressor fridge, a single roof fan, and an inverter kept small on purpose. The daily draw is modest, which is the whole reason a couple of panels and a small battery carry a full-time van.
| Load | Wh/day | Basis |
|---|---|---|
| LED interior lights | 100 | A handful of 6 to 10 watt LED fixtures run four or five evening hours. An RV has more of them. |
| Roof vent fan | 200 | A 12V vent fan pulls 30 to 45 watts and often runs low all night in summer. RVs frequently have two. |
| 12V compressor fridge | 500 | The largest steady draw in most rigs: a 40 to 60 watt compressor cycling roughly half the day. Bigger box, bigger figure. |
| Water pump | 40 | A 12V demand pump only runs while a tap or the shower is open. Minutes a day, not hours. |
| Device and laptop charging | 120 | Phones, a tablet, a laptop, a camera battery. The RV figure adds a second person and a bigger laptop. |
| Inverter loads (TV, blender, tools) | 240 | Anything that needs 120V AC through the inverter: a small TV, a blender, charging power tools. Occasional, but it adds up. |
| Total | 1,200 | Our planning figure for this rig. Swap in your own. |
Each figure is a watt draw times the hours the load truly runs, not the hours it is switched on. The compressor fridge cycles on and off; the fan idles on low; lights are an evening thing. That gap between switched-on and actually-drawing is where most online RV numbers go wrong.
Panels by peak sun hours
The same 1,200 Wh a day, counted at 100W and 200W panels across the sun range you might travel through. The right column shows what the rounded-up 100W count actually makes against the load. Panels round up: a fraction of a panel is a panel you do not have.
| Peak sun hours | 100W panels | 200W panels | Daily output (100W) |
|---|---|---|---|
| 4.0 h | 4 | 2 | ~1.23 kWh vs 1.2 used |
| 4.5 h (US avg) | 4 | 2 | ~1.39 kWh vs 1.2 used |
| 5.0 h | 4 | 2 | ~1.54 kWh vs 1.2 used |
| 5.5 h | 3 | 2 | ~1.27 kWh vs 1.2 used |
| 6.0 h | 3 | 2 | ~1.39 kWh vs 1.2 used |
| 6.5 h | 3 | 2 | ~1.5 kWh vs 1.2 used |
Travel changes your sun figure more than a house ever does. A summer in the Southwest is a 6.5-hour climate; a winter parked in the Pacific Northwest is closer to 3. Size for the darkest place you plan to sit still in, not the sunniest place you drive through.
Roof space is the real limit
A high-roof van roof is generous on paper and stingy in practice. A roof fan sits in the middle of it, a second vent or a small AC unit takes more, and the curve of the roof edges is dead space for rigid panels. Many builds land on two 200W panels down the centerline, or a pair of flexible panels glued to the curve, rather than the four 100W panels a flat roof would hold.
4 100-watt panels take about 22 sq ft of clear roof (three 200W panels land close to the same footprint). That is the ceiling most rigs hit first: not the math, the metal. If the roof will not hold the count, the fix is fewer, thirstier days or a bigger battery to ride the shortfall, not a panel that will not fit.
The battery is the other half
Panels answer the daytime question. The night question, running the fridge and the fan until sunrise, is a battery question, and your 1,200 Wh a day is exactly the input that sizes it. Run that figure through the solar battery size calculator to see the usable amp-hours to carry, then come back and let these panels refill it.
Kitting out a van roof? Shop solar kits on Amazon (sponsored)
Questions people ask
How many solar panels does a camper van need?
About 4 100-watt panels, roughly 400 watts of rooftop solar, for a camper van drawing 1.2 kWh (1,200 Wh) a day at the national-average 4.5 peak sun hours. Strong desert sun brings it to 3; cloudy skies push it to 4. In 200-watt panels that is about 2, which fit a tight roof better.
What size panels do people use on a roof this small?
Mostly 100W or 200W rigid panels, plus flexible panels for curved or crowded roofs. Higher-wattage residential panels are physically too big to place well up there. This page counts in 100W and 200W because that is what actually bolts down on a rig.
Do these panels run the rig at night?
No. Panels make nothing after sunset, and a fridge and a fan run all night. The panels refill the battery by day; the battery carries the dark hours. Your 1,200 Wh a day is the number that also sizes that battery, on the battery size calculator.
Where does the daily watt-hour figure come from?
We added up the 12V loads in the table: lights, a roof fan, a compressor fridge, the water pump, device charging, and occasional inverter use. It lands at 1,200 Wh a day for this rig. Yours will differ, so a clamp-on watt-meter answers it for your actual setup in a day of camping.