Campervan Solar Setup: The Definitive Guide (2025)

· 5 min read

A well-designed campervan solar setup gives you genuine off-grid freedom — the ability to park anywhere and know your batteries will be topped up by morning. This guide covers everything from panel selection to charge controller sizing, specifically for the UK and European climate.

For how solar fits into your overall electrical system, see our complete campervan electrical system guide.

Size your solar system in 2 minutes

Our free calculator works out exactly how many watts of solar you need based on your actual power usage. No sign-up required.

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How Much Solar Do You Need?

The answer depends on three things: your daily energy consumption, your location, and the time of year.

For the full calculation method, see how many solar panels do I need. For a quick comparison of common setups, check 200W vs 400W vs 600W solar.

Rule of thumb for the UK:

  • Weekend van, basic needs: 100–200W
  • Full-time, moderate usage: 300–400W
  • Full-time with high usage: 500–600W

These figures account for the UK's average 3–4 peak sun hours. In southern Europe you'll get 5–7 peak sun hours — nearly double the output.

Winter Considerations

Solar output drops dramatically in UK winters — expect 25–40% of summer output. This is why most systems also need a DC-DC charger for alternator charging while driving. See how much solar do I need in winter for real UK data.

Choosing Solar Panels

Rigid vs Flexible

For a detailed comparison, see best solar panels for campervans.

Rigid panels: More efficient (20–22%), last 25+ years, better value per watt. Need brackets or a roof rack.

Flexible panels: Lower profile, lighter, can conform to slight curves. Less efficient (18–20%), shorter lifespan (5–10 years), can overheat on flat roofs.

For specific guidance on flexible panels, see can flexible panels handle roof curves. To see how much solar your specific van model can fit, check roof space by van model.

Brand Comparison

The two most popular brands for campervans are Victron and Renogy. See Renogy vs Victron solar panels for our detailed comparison.

Portable Solar

Don't rule out portable panels — they can be angled toward the sun and avoid roof clutter. See portable solar panels for campervans for when they make sense.

Charge Controllers

The charge controller sits between your solar panels and battery, regulating the voltage and current. You have two options:

MPPT vs PWM

Always use MPPT for systems over 100W. MPPT controllers are 95–99% efficient vs 75–80% for PWM, which means significantly more power from the same panels. See MPPT vs PWM charge controllers for the full comparison.

Sizing Your Controller

The controller needs to handle both the solar array's output current and voltage. Get this wrong and you'll either waste power or damage the controller. See solar charge controller sizing for the calculation.

The Victron SmartSolar MPPT 100/30 is the most popular choice for systems up to 440W at 12V. See our Victron SmartSolar setup guide for installation instructions.

Match your controller to your panels

Check the maximum input voltage (Voc) of your panels and make sure it's below your controller's maximum. Wiring panels in series adds voltage — two 40V panels in series = 80V input.

Panel Wiring: Series vs Parallel

How you wire your panels together affects performance, especially in partial shade. See solar panels in series vs parallel for the full explanation.

Short version: Parallel is safer and more shade-tolerant for campervans. Series gives higher voltage (useful for long cable runs) but one shaded panel kills the whole string.

Shading Impact

Roof-mounted accessories (fans, antennas, roof bars) can shadow your panels. See solar panel shading: how much power do you lose for the real numbers.

Mounting & Installation

Mounting Options

See campervan solar panel mounting for the full guide covering:

  • Roof brackets — most common, allows airflow underneath (improves efficiency)
  • Adhesive mounting — lower profile, no drilling, but panels can overheat
  • Tilt mounts — maximum output, but higher wind profile

Cable Routing

Getting cables from the roof panels to the interior charge controller requires a weatherproof penetration through the roof. See how to route solar cables through your van roof for the step-by-step process.

Waterproofing is critical

A poorly sealed roof penetration will leak. Use a proper cable gland (not just silicone) and test it before you drive in rain.

Use our free calculator to get a precise solar recommendation for your specific setup.

FAQ

How many solar panels can I fit on a campervan?

It depends on your van model. A long-wheelbase Sprinter or Transit can typically fit 600–800W of rigid panels. A shorter van like a VW Transporter might only fit 200–300W. See our roof space by van model guide for specifics.

Do solar panels work in the UK?

Yes, but output varies significantly by season. In summer you can expect 4–5 peak sun hours per day, generating good power. In winter, that drops to 1–2 hours. Most UK van builds supplement solar with a DC-DC charger for reliable year-round charging.

Can I install solar panels myself?

Absolutely. Solar panel installation is one of the more straightforward parts of a van electrical build. The main skill required is making a weatherproof roof penetration. Our calculator sizes everything for you — you just need to follow the wiring diagram.