BUYING GUIDE · NOMAD
How to Pick a Solar Setup for Van Life
Power budget first, panels second — the order matters more than the spec sheet.
April 19, 2026 · 6 MIN READ
Power budget first, panels second — the order matters more than the spec sheet.
The most common van solar mistake is buying panels based on a rough number — "400 watts should be enough" — without first calculating what you actually need. Start with a load audit: every device you plan to run, its wattage, and how many hours per day.
A laptop (65W) running 6 hours: 390Wh. A 12V compressor refrigerator (40W average): 960Wh/day. Lighting (20W total): 40Wh. Phone and misc charging: 100Wh. That is already 1,490Wh before you add anything else. Once you know your daily consumption, you can size battery and panels around it rather than guessing.
Lithium iron phosphate (LiFePO4) batteries have become the default for van builds, and for good reason. Compared to AGM lead-acid: LiFePO4 can be discharged to 20% (80% usable capacity); AGM should only go to 50% (50% usable). A 200Ah LiFePO4 bank has the same usable capacity as a 320Ah AGM bank at roughly half the weight.
Cycle life: 2,000–4,000+ cycles versus 400–600 for AGM. LiFePO4 also accepts much higher charge current and charges faster. The upfront cost is higher ($900–1,400 for 200Ah vs $300–400 for AGM). The long-term cost is lower. For any build intended to last more than two years, LiFePO4 is the correct choice.
Monocrystalline panels are more efficient (20–22%) than polycrystalline (15–17%) and perform better in low-light conditions. The efficiency advantage means smaller physical footprint for the same wattage — important on a van roof with limited real estate.
Rigid aluminum-framed panels are more efficient and significantly more durable than flexible panels; they last 25+ years. Flexible panels (common on curved roofs) degrade faster, trap heat underneath (heat reduces efficiency and can damage the van roof over time), and have shorter lifespans. Unless your roof geometry makes rigid panels impossible, go rigid.
The charge controller sits between panels and battery, managing the charging process. MPPT (maximum power point tracking) controllers are 15–30% more efficient than PWM (pulse width modulation) controllers under typical conditions. On a full build, an MPPT controller pays for the price premium in weeks. Always buy MPPT.
An inverter converts 12V DC battery power to 120V AC. Size it to your largest single appliance with some headroom. Pure sine wave inverters are required for sensitive electronics (laptops, medical equipment). Do not overbuild the inverter — a 3,000W unit draws significant idle current. A 1,500W pure sine inverter covers most van life needs.
Most first-time builders underestimate panel needs by 30–50%. A 200W panel delivers 200W only under ideal conditions: direct sun, 77°F panel temperature, no shading, optimal angle. Real-world conditions require a derating factor of 50–70% of rated output as your planning number.
If you calculated you need 1,500Wh/day and want 5 hours of usable sun, you need 600W of panels minimum — more realistically 800W once you account for cloudy days, travel through shaded areas, and the reality of parking in trees. Build in headroom; the regret is always from undersizing, not oversizing.