Most people start camper solar with the panel wattage, but the useful number is the watt-hours your camper uses in a day, and it takes ten minutes with a pen to work out.
Solar power for a camper is a roof or portable panel feeding a charge controller, which refills a battery that runs the loads. Sized from daily watt-hours divided by sun hours, a weekend camper with lights, fan and phones typically needs 100 to 200 W, and a van or motorhome running a 12 V compressor fridge and laptop needs 200 to 400 W. Bigger rigs start at 400 W.
The guide below covers the four parts of a camper system, a worked table of daily watt-hours for a two-person van, and six numbered steps that turn that total into panel watts and battery size. It then compares rigid, flexible and portable panels, shows how the numbers change from a camper van to a motorhome, and ends with a spec table to check before ordering. Finished layouts for different roof types are on the page for RV and campervan solar setups.
What is solar power for a camper made of?
Solar power for a camper is a four-part system wired in a chain: a solar panel feeds a charge controller, the controller charges a battery, and the battery runs the loads. A fuse or breaker sits close to the battery positive terminal to protect the wiring between them.
- Solar panel: makes DC power whenever light reaches the cells, including while the camper is on the road. A roof panel stays fixed, while a portable panel can be carried into the sun.
- Charge controller: regulates the charge going into the battery. Under about 200 W a PWM controller can be enough; above that, or with higher panel voltage or partial shade, an MPPT controller typically yields 10 to 30 % more energy.
- Battery: stores the energy the camper uses after sunset and on cloudy days. Lithium iron phosphate (LiFePO4) batteries typically allow a deeper usable discharge than lead-acid.
- Loads: the lights, vent fan, fridge, water pump and device chargers the battery runs. Camper loads are typically 12 V DC, and an inverter is only needed for devices that require AC power.
The battery is the fuel tank, the panel is the pump that refills it, and the controller is the valve between them. That is why panel watts and battery watt-hours are sized separately, both from the same daily energy figure.
Battery capacity is easiest to compare in watt-hours. According to PVEducation's battery capacity reference, Wh capacity is approximated by multiplying Ah capacity by the nominal battery voltage, so a 100 Ah LiFePO4 battery at 12.8 V holds about 1,280 Wh. Charging a laptop from a 12 V DC charger typically wastes less of that energy than running it through an inverter.
Panel voltage has to suit the battery before the chain works, and the guide on matching a panel to a 12 V battery walks through that check. The controller choice is covered in more depth in how MPPT and PWM controllers differ.
Solar keeps charging the house battery while the camper drives. To add alternator charging, fit a dedicated DC-DC charger rather than wiring the alternator into the solar controller.
How much solar power does a camper need per day?
A camper needs as much solar power as it uses in watt-hours per day, and a camper van running a 12 V compressor fridge, lights, a roof vent fan, phones, a laptop and a water pump typically lands around 750 to 800 Wh. Panel watts and battery capacity are both sized from that daily watt-hour figure.
A watt-hour (Wh) is one watt drawn for one hour, so each device's daily use is its draw in watts multiplied by the hours it runs. According to Virginia Cooperative Extension (2020), daily use is wattage × hours, divided by 1,000 to give kWh, and a refrigerator's full-power hours are about the time it is plugged in divided by three because it cycles on and off.
That one-third rule sits inside the duty cycle of a 12 V compressor fridge, which runs about 30 to 50 % of the time in mild weather. Hot days, a warm interior and frequent door openings push the duty cycle higher, so the fridge row is the first one to recheck for summer trips.
The table below works through one typical day for two people in a camper van, with the method applied to each load.
| Load | Typical draw (W) | Hours per day | Wh per day |
|---|---|---|---|
| 12 V compressor fridge | about 45 | 8 (one third of 24 h) | about 360 |
| 4 LED lights | 3 each, 12 total | 5 | 60 |
| Roof vent fan | about 20 | 6 | 120 |
| 2 phones | varies by charger | 1 full charge each | about 30 (15 each) |
| Laptop | about 60 | 3 | 180 |
| Water pump | about 60 | 0.25 (15 min) | 15 |
| Total | about 765 |
These are typical draws, not measurements. Read the label on each of your own devices and replace the figures before you size anything.
The fridge accounts for close to half the daily total, about 360 Wh or roughly 30 Ah from a 12 V battery. A camper with a compressor fridge therefore needs far more solar than one that only runs lights and charges phones.
Add 20 to 30 % to the total for controller, wiring and heat losses, which takes the example to around 920 to 1,000 Wh. Skip that margin if you size the panels with a derate factor, as the step-by-step method in the next section does, because applying both counts the same losses twice.
For weekend and multi-day setups sized with the same watts × hours method, the page on camping and overlanding power builds also covers how many days of battery to carry for warm trips versus cold or cloudy ones.
How do you size camper solar panels, step by step?
Camper solar panels are sized by dividing daily watt-hours by peak sun hours times a derate, rounding up to the next panel size, and then sizing the battery to carry one to two nights. The whole calculation fits on one page, and it starts from the 765 Wh worked example for a two-person camper van.
- Total your daily watt-hours from the load table. The example camper van uses about 765 Wh a day.
- Look up the peak sun hours for the worst month you plan to travel. Size for that month, because summer sun overstates what the panel delivers in spring or autumn.
- Multiply the peak sun hours by a 0.7 derate to cover controller, wiring, heat and dust losses. At a typical summer mid-latitude figure of 4.5 sun hours, each panel watt yields about 3.15 Wh a day.
- Divide daily Wh by that yield to get panel watts. The example gives 765 ÷ 3.15 ≈ 243 W, which rounds up to 300 W of panels.
- Size the battery in usable Wh by multiplying daily use by days of autonomy, 1 to 2 days for warm, dry trips and 2 to 3 days for cold or cloudy camping. At 1.5 days the example needs about 1,150 Wh, and a 100 Ah lithium iron phosphate battery at 12.8 V nominal holds about 1,280 Wh (Ah × nominal V).
- Pick the charge controller by type and current. Above about 200 W an MPPT controller is the usual choice, and its rated current should sit above array watts ÷ battery voltage, around 25 A for 300 W on a 12 V battery.
- Fit a fuse or breaker near the battery positive and a low-voltage disconnect. Compressor fridges and radios dislike low voltage.
Peak sun hours are the average daily solar energy a site receives in kWh/m² per day, so a site receiving 8 kWh/m² per day has 8 hours of sun at 1 kW/m², according to PVEducation. The worst month matters because Denver, Colorado, near 40° latitude, receives nearly three times more solar energy in June than in December, according to the U.S. Department of Energy.
At 4.5 sun hours × 0.7, a 100 W panel gives about 315 Wh a day, which covers lights, phones and a roof fan but not a compressor fridge through the night. A 200 W array gives about 630 Wh a day, and a 400 W array gives about 1,260 Wh, enough for the 765 Wh example with room for a cloudy day. For the single-panel view, see what a single 100 W panel runs, device by device.
Rigid, flexible or portable: which solar panel suits a camper roof?
The roof decides the panel type: a rigid framed solar panel fits a flat, open camper roof with room for brackets, while a flexible ETFE solar panel goes on a curved, crowded or weight-sensitive roof. A portable solar panel covers the third case, a camper that parks in shade. Many campers run two of the three.
Rigid framed panels: open roofs and tilt
A rigid framed glass panel runs slightly cooler because air moves underneath it, and it can be tilted toward a low sun. Tilt brackets come in 22, 28 and 41 inch sizes, and the 41 inch size is listed for horizontal panels up to 400 W. The tradeoff is extra height and weight on the roof.
Flexible panels: curves, crowded roofs and low weight
A flexible solar panel follows a gently curved roof and sits close to the surface, keeping height and weight low. The LinkSolar flexible family comes in 50 W, 100 W and 135 W, with an ETFE front and back-contact cells at about 24.8 to 25 % efficiency. The 100 W panel measures about 1247 × 418 mm and weighs 1.0 kg.
ETFE resists UV best but costs more, while a PET front costs less and tends to yellow after around two to three years outdoors. Compare the 50 W, 100 W and 135 W flexible panels against the gaps between your roof fan, rack and vents. Fixing methods are covered in a separate guide to mounting flexible panels on an RV roof.
Portable panels: parked in the shade
A portable solar panel wins when the camper sits under trees or an awning. A 120 W portable panel aimed at the sun produces more than a 200 W roof panel under awning shade, so the roof panel covers drive days and the portable covers parked stays of several days.
The 11 W foldable charger has a narrower job: it weighs 198 g, folds to 245 × 158 mm and charges phones and power banks over a 5 V / 2.4 A USB output, storing no energy itself. On a stored motorhome, an 11 W portable charger keeps the starter and house batteries topped up. The larger foldable panels you carry to the sun handle the shaded-campsite role.
Mixing roof and portable panels
Many RVs mix panel types: rigid panels on open sections, flexible panels around vents and curves, and a portable panel for shade. One common camping layout pairs 2 × 100 W flexible panels on the roof with a 120 to 160 W portable panel.
Camper van vs motorhome: how the numbers change
A motorhome with solar panels usually needs more watts and more battery than a camper van, because it carries a bigger fridge, more people and more devices, and it usually has the roof length to fit the extra panels. The sizing method stays the same: daily watt-hours divided by sun hours. The inputs are what grow.
Camper van roofs
A camper van roof typically fits 2 to 4 panels around a roof fan and a rack. That matches the 200 to 400 W tier the LinkSolar RV page gives for full-time vanlife and Class B builds, which covers a 12 V compressor fridge, vent fans, laptops and a router.
Flexible panels often fill the gaps between the fan and the rack, because they follow gentle curves and add little height or weight.
Motorhome roofs
Motorhome solar panels have a longer roof to work with, but that roof also carries more vents, skylights and air conditioning housings. The RV page places power-hungry rigs at 400 W and up, with work rigs designed in a 400 to 800 W range.
A common layout puts rigid panels on brackets across the open sections, where they run slightly cooler with airflow underneath and can be tilted, and uses flexible panels as infill around the obstacles.
Four things change in a motorhome solar system compared with a van:
- Fridge size. A larger motorhome fridge often uses around double the daily watt-hours of a van fridge, as a typical figure; read the label on your own unit.
- Headcount. Lighting, water pump use and device charging scale with each extra person on board.
- Battery voltage. 24 V battery banks become common on larger builds, and the LinkSolar flexible panel family suits 12 V or 24 V battery systems.
- Storage. A motorhome often sits parked for months, and the RV page shows an 11 W portable charger keeping the starter and house batteries topped during long storage.
Odd roof sections, such as a curved cab-over or a narrow strip between two skylights, are where a custom laminate fits better than a stock size. LinkSolar sources flexible panels built to a roof's shape through its partner factories. For the camper van end of the range, read about a full van build with back-contact cells.
Specs to compare before you order
The specs to compare before you order solar power for a camper are power, operating voltage, size, weight and mounting route, checked against your roof and battery voltage rather than headline wattage. The table compares the LinkSolar flexible panels, foldable charger and MPPT controller on those points.
| Panel or part | Power | Voltage (Vmp / output) | Approx size | Weight | Mounting route | Suits |
|---|---|---|---|---|---|---|
| 50 W flexible panel | 50 W | About 9 to 18 V Vmp | See product page | 0.7 to 0.9 kg | Adhesive, snap fasteners or rivets | Infill around a van roof fan |
| 100 W flexible panel | 100 W | 18.05 V Vmp, 21.63 V Voc | About 1247 × 418 mm | 1.0 kg | Same as 50 W | Camper van roof, 2 to 4 units |
| 135 W flexible panel | 135 W | About 19 to 20 V Vmp | About 545 × 1180 to 1374 mm | 1.8 to 2.0 kg | Same as 50 W | Motorhome or trailer roof |
| 11 W foldable charger | 11 W | 5 V USB, 2.4 A | 245 × 315 mm open | 198 g | Carried to the sun | Phones, power banks, storage trickle |
| 10 A 12 V MPPT controller | 10 A rated | 12 V battery, USB-A and USB-C out | See product page | See product page | Inside, near the battery | One 100 W panel on a 12 V battery (typical) |
Figures from the LinkSolar catalogue (23 September 2026) and live pages (25 September 2026); mounting hardware is not included. The last row is a compact 10 A MPPT controller; check array Voc and its current limit before wiring.
The LinkSolar RV solar panels page shows how these parts combine into complete roof layouts, from 100 W weekend setups to 400 W and up work rigs.
Read the voltage column first: the 100 W and 135 W panels sit around 18 to 20 V at Vmp, and the flexible family suits 12 V or 24 V battery systems. Then hold the size column against the clear roof length between your fan, vents and rack. The 11 W foldable charges phones and power banks; it does not store electricity.
FAQ: solar power for a camper
Is 100 watts a lot of power for a camper?
A 100 W solar panel is a modest amount of power for a camper, producing about 315 Wh a day at a typical summer assumption of 4.5 peak sun hours and a 0.7 derate. That covers LED lights, phone charging and a roof vent fan.
A 12 V compressor fridge running through the night needs more. Plan on around 200 W of panel plus a battery sized for one to two days of use.
Will a 200 W solar panel run a 12 V fridge?
A 200 W solar panel can typically run a 12 V compressor fridge in summer, because a typical fridge uses around 30 Ah a day and the panel yields about 630 Wh, roughly 52 Ah at 12 V.
The battery carries the fridge overnight, so size it for one to two days. In winter, or with the camper parked in shade, daily yield drops and the same panel may fall short.
What is the best motorhome solar panel?
The best motorhome solar panel is the one that fits the roof layout and matches the battery voltage. Rigid framed panels suit open, flat roof sections, run slightly cooler with airflow underneath and can be tilted.
Flexible ETFE panels follow curved sections, keep height and weight low, and suit 12 V or 24 V battery systems. Many motorhomes use a mix of both.
Does solar charge the camper battery while driving?
Solar panels charge a camper battery while driving, because they produce power whenever daylight reaches them, parked or moving. To add alternator charging, use a dedicated DC-DC charger instead of wiring the alternator into the solar controller.
A clean roof panel produces more on every drive, and the guide to keeping roof panels producing year to year covers the routine.
Next step
Add up the daily watt-hours for your own loads, then note your roof length and battery voltage. Send those figures when you request a quote, and LinkSolar confirms the panel layout and controller before you order. The camper and motorhome roof layouts page shows the setups these parts go into.