Start with a roof plan, not a product
Draw your roof to scale. Mark the roof fan, any skylight, the roof rack feet, aerials and ribs. Only then fit panel footprints. Many builders discover that two mid-size panels fit better than one large one – and that the roof fan position decides everything. Pick your roof vent fan location first.
Electrical safety. 12 V systems carry high currents that can start fires; mains (120/230 V) wiring can kill. Fuse every positive cable at its source, size cables to the manufacturer's tables, and have your system designed or checked by a qualified auto-electrician. Mains wiring should be done by a qualified electrician.
Rigid vs flexible
| Rigid (framed) | Flexible | |
|---|---|---|
| Durability | Generally higher | More vulnerable to heat and flexing |
| Weight | Heavier | Very light |
| Profile | Raised on brackets or rack | Almost flush |
| Cooling | Air gap underneath | Often none if glued down |
| Typical use | Full-time builds, roof racks | Curved roofs, stealth builds |
What to check on a panel spec sheet
- Rated power (W) under standard test conditions – real output on a van is lower due to heat, angle and shading.
- Voc and Vmp – must suit your charge controller's input limits, especially in cold weather when voltage rises.
- Dimensions and weight – against your roof plan and roof-load limits.
- Cell type and bypass diodes – shading of one corner can hit output hard on some designs.
- Warranty terms on power output and materials.
Series or parallel?
Series raises voltage (good for long cable runs and MPPT efficiency, worse with partial shading). Parallel keeps voltage low and tolerates shading better but needs thicker cables and fusing per string. Your controller manual sets the limits.
Controllers
An MPPT controller is the standard choice. You can use a standalone unit (e.g. Victron SmartSolar) or a combined DC-DC + MPPT charger – see Victron vs Renogy.
Brands to shortlist
Renogy, Victron, BougeRV, Sunman (flexible) and many regional brands make van-suitable panels. We'll add verified spec cards for specific models once affiliate programmes are confirmed – until then, compare data sheets with the checklist above.
Frequently asked questions
Rigid or flexible solar panels for a van?
Rigid aluminium-framed panels are generally more durable and run cooler because air flows underneath. Flexible panels are lighter, lower-profile and stealthier, but bonded directly to the roof they run hotter, which can shorten their life.
How many watts of solar can fit on a van roof?
It depends on the roof length, the fan and vent positions and the panel dimensions. Draw your roof to scale with every vent, rack and antenna before choosing panel sizes.
Do I need an MPPT controller?
For most van systems, yes. An MPPT controller extracts more energy than a PWM controller, especially when panel voltage is well above battery voltage. Some DC-DC chargers include one.
Spotted an outdated spec? Tell us.