Solar panels let you run lights, a fridge, a water pump and your devices at a campsite, cabin or anchorage without a generator. This guide covers the three types of small solar panels, how to size a system for an RV, van, boat or off-grid cabin, and what else you need to make it work in Canadian conditions.
Rigid vs flexible vs foldable panels
| Rigid (framed) | Flexible | Foldable / portable | |
|---|---|---|---|
| Best for | RV and van roofs, cabins, boats with a flat mounting area | Curved roofs, boat biminis, where weight is critical | Camping, tailgating, charging a power station |
| Efficiency | Highest | Lower | Medium |
| Weight | Heaviest | Lightest | Light, carried by hand |
| Lifespan | 25+ years | Shorter, especially when mounted flat on a hot roof | Depends on handling and storage |
| Mounting | Brackets with an air gap underneath | Adhesive or screws, flat to the surface | Kickstand; set up in the sun and pack away |
Rigid panels are the best value per watt and the most durable choice for anything permanently installed. The air gap under a bracket-mounted panel keeps it cooler, and cooler panels produce more power. See our rigid monocrystalline solar panels.
Flexible panels bend to fit curved roofs and weigh a fraction of a rigid panel, but they run hotter when glued flat and usually wear out sooner. Choose them only when a rigid panel won't fit or the weight matters.
Foldable panels fold into a carry case and stand on a kickstand. You can park in the shade and set the panel in the sun, and angle it toward the sun through the day. They pair naturally with a portable power station. See our foldable and portable solar panels.
How many solar watts do you need?
- List what you will run and for how long. Multiply each device's watts by the hours used per day. A 12V compressor fridge might use 400–700 Wh a day, LED lights 50–100 Wh, a water pump 50 Wh, phones and laptops 100–200 Wh, and a furnace fan 300–600 Wh on cold nights.
- Add it up to get your daily watt-hours (Wh).
- Divide by your sun hours, then allow for losses. In a Canadian summer, plan on about 4 to 5 hours of full sun per day; in spring and fall, 2 to 3. Divide your daily Wh by the sun hours, then add about 25% for heat, dirt, angle and charging losses.
Example: 1,000 Wh a day ÷ 4 sun hours = 250W, plus 25% = about 315W, so two 200W panels would cover it in summer with some margin. Most weekend campers do well with 200W to 400W; full-time RVers and off-grid cabins usually need 600W to 1,200W or more.
The rest of the system
Charge controller: MPPT vs PWM
A charge controller sits between the panels and the battery. PWM controllers are cheap and fine for one or two small panels. MPPT controllers convert extra panel voltage into extra charging current and typically harvest 15% to 30% more energy, especially in cold weather and with panels wired in series. For more than about 200W, choose MPPT. See our solar charge controllers and our guide to MPPT controllers and panel voltage.
Battery
LiFePO4 (lithium iron phosphate) batteries weigh about half as much as lead-acid, can be used down to 80% to 100% of their capacity, and last thousands of cycles. Most LiFePO4 batteries should not be charged below 0°C, so in cold weather keep the battery inside the heated space or choose a self-heating model. See LiFePO4 batteries for RVs and cabins and our guide to charging LiFePO4 batteries with solar.
Inverter
To run 120V appliances, add a pure sine wave inverter sized for the largest load you will run at once, plus a margin for motor start-up surges.
12V or 24V?
Most RVs and vans run 12V. Systems above about 1,500W of inverter power, such as cabins and full-time rigs, are often better at 24V or 48V because lower current means thinner, cheaper wiring and less loss.
Mounting and setup tips
- Mount rigid panels on brackets so air can flow underneath, and seal every roof penetration with a self-levelling sealant made for RV roofs.
- Keep panels clear of roof vents, the air conditioner and anything that casts a shadow; even partial shade on one panel can cut a series string's output sharply.
- Use UV-rated solar cable, a fuse or breaker between the controller and the battery, and properly sized wire to keep voltage drop under about 3%.
- On the road, a tilt bracket or a foldable panel you can aim at the sun can add 20% or more in spring and fall when the sun is low.
- On boats, use marine-grade connectors and stainless hardware; see our guide to installing rigid solar panels on a boat.
Complete kits
If you would rather not match parts yourself, our off-grid solar systems for RVs and cabins combine panels, a charge controller, battery and inverter that are sized to work together, and our solar panel kits pair panels with a controller.
Frequently asked questions
Can solar panels run an RV air conditioner?
Only with a large system: a rooftop air conditioner draws about 1,200–1,800W while running, so you would need a big battery bank, a large inverter and more roof space than most RVs have. Solar is better suited to everything else.
Will solar keep my RV battery charged in storage?
Yes. Even a 50W to 100W panel with a controller will offset the small drains in a parked RV. Store LiFePO4 batteries disconnected and above freezing over the winter.
How long do portable solar panels last?
Rigid panels last 25 years or more. Foldable panels typically last several years with careful handling; keep them dry, don't fold them while wet and store them flat.
Need help sizing a system for your RV, van, boat or cabin? Call us at 1-800-858-4318 or send us your list of appliances.
