Solar panel prices have dropped roughly 80% in the last decade. What used to cost $2,000+ for a van setup now costs $200-400. The technology is mature, reliable, and the brand differences matter less than you think.
Use our electrical planner to figure out how much solar you need, then err on the high side — panels are cheap enough now that extra capacity is worth it. Go with rigid monocrystalline from any reputable budget brand.
This depends entirely on your power usage. The best way to figure out your needs is to use our electrical planner or do a power audit — list everything you'll run, estimate daily usage, and let the math tell you how much solar to install.
Solar panels have gotten cheap enough that it makes sense to install more than you think you need. Extra capacity gives you a buffer for cloudy days, winter, and the devices you'll inevitably add later. If your calculator says 400W, consider 600W. The marginal cost of an extra panel is small compared to the frustration of not having enough power.
Also consider your roof space and plan for expansion — even if you don't install all your panels now, running the wiring for future panels during your build is much easier than doing it later.
Remember: Solar is only half the equation. If you also have a DC-DC charger (and you should), driving recharges your batteries too. Factor both sources into your planning.
This is your main decision. Both are monocrystalline (the cell type that matters), but the form factor is very different.
Unless you have a specific reason to go flexible (stealth, height clearance for parking garages), rigid panels are the better value. They last 5-10x longer and perform better in hot weather. The "easier installation" of flexible panels doesn't make up for replacing them every few years.
Quick summary below. The one rule you can't skip: a cold panel produces a higher open-circuit voltage than its STC spec, so a series string that looks fine in summer can fry your charge controller on a -10 °F morning. For two 200W panels in series the math is generous; for three or more, run the worst-case Voc formula or use NEC 690.7(A)'s 1.25× rule against your controller's PV max before you wire anything. Full derivation in the string sizing section of the charge controllers guide.
Series (daisy chain)
Adds voltage, same amps. Better for long wire runs. But if one panel is shaded, the whole string drops.
Parallel (each panel direct)
Same voltage, adds amps. Shading one panel doesn't affect others. Needs thicker wire.
For most vans: 2 panels in parallel is the default — that's what the electrical planner sizes around, and a MaxxAir fan or AC unit on the roof almost guarantees one panel will be shaded at some point. Move to series only if the run from roof to charge controller is long enough that voltage drop is dragging your harvest down, your roof is shade-free, and you've checked the cold-temp Voc math against your controller's PV max (see below).
Roof space reality check: A typical van roof (Sprinter, Transit, ProMaster) fits 2-4 rigid panels depending on what else is up there (vent fan, AC unit, roof rack). Measure your available space before buying.
A four-panel rooftop array feeding an MPPT controller, paired with a 2-battery (560Ah) bank and 60A DC-DC. Hover the solar-to-MPPT wire to see the gauge for a long roof-to-bay run.
Educational estimates only — not a substitute for a licensed electrician. Verify against ABYC E-11 and manufacturer specs before installing. See full disclaimer.
BETA — Educational estimate, not an engineered design.
Verify all wire gauges, fuse and breaker ratings, run lengths, and system sizing against ABYC E-11, manufacturer spec sheets, and a licensed electrician before installing or energizing. Ampacity uses ABYC E-11 single-conductor, free-air, 105 °C-insulation copper (typical marine BC-5W2); resistance is NEC Ch. 9 Table 8 at 75 °C; system is nominal 12 V DC and 120 V AC. Wire rated below 105 °C, ambient-temperature derating, and bundle derating are not applied. No code-compliance review or engineering sign-off is provided or implied.
Source: morevanlessmoney.com/tools/electrical/diagram · Full terms: morevanlessmoney.com/legal/terms
Here's the thing about solar panels: they're a commodity product. The solar cells inside a $100 panel and a $250 panel are often made in the same factories. The brand premium mostly pays for marketing, packaging, and customer support you'll probably never need.
Vevor 200W monocrystalline panels run roughly $0.43/W and ship from US warehouses — the budget pick across the electronics guides. Renogy is the brand the van community defaults to and runs about $1.00/W (we cover when premium is worth the upcharge); same cell chemistry, more polished packaging, longer warranty support if you ever need it. Both last 20+ years in practice.
A 200W rigid monocrystalline Vevor panel runs ~$80-130. Two panels (400W total) come in around $160-260. Renogy's equivalent is closer to $200 per panel.
Many brands sell "complete solar kits" bundled with a cheap PWM charge controller and thin wiring. You're better off buying the panel separately and pairing it with a proper MPPT charge controller - you'll get 20-30% more power from the same panels.
Your panels will almost never produce their rated wattage. A "200W" panel produces 200W under perfect lab conditions (direct sunlight, 25°C, optimal angle). In real life:
Multiply your panel wattage by 4 to estimate daily watt-hours in decent sun. So 200W of solar ≈ 800Wh/day, 400W ≈ 1600Wh/day. This is conservative but realistic for flat-mounted van panels.
Rigid panels mount to your roof with Z-brackets or L-brackets and self-tapping screws (with sealant). Leave a 1-2" gap between the panel and roof for airflow - this keeps the panel cooler and more efficient.
You need to run wires from the panels through the roof to your charge controller inside. Use a weatherproof cable entry plate (also called a gland box) - these cost $5-10 and create a sealed pass-through. Apply Dicor self-leveling sealant around it.
Use 10 AWG PV cable (UV-rated, dual-jacketed) for runs under 20 ft at 200-400W — the ABYC 3% drop math works out and the insulation survives the roof. MC4 connectors are the standard waterproof snap-fit. Run the wire to your charge controller, then to your battery through a properly sized fuse — the wiring guide walks AWG selection for longer runs and the fuses-and-breakers guide covers the inline solar fuse and charge-controller-to-battery sizing.
Use the electrical planner to calculate your needs, then err on the high side — extra solar is cheap insurance. Go with rigid monocrystalline panels from any budget brand and pair with an MPPT charge controller.
Solar technology is mature and reliable. The brand matters far less than getting the right amount of capacity for your needs and leaving room to expand.