Picture this: it is Saturday night, the fridge has stopped humming, your phone is at 2% and the campsite has no electric hook-up. It is the classic off-grid letdown, and it is exactly why so many van owners in the UK and US are switching to solar panels for a campervan.
This guide walks you through how a solar setup works, how to size it for your own habits, what you will really pay and how to fit it without damaging your van or your battery.
Why Solar Panels for a Campervan Are Worth It
A leisure battery empties faster than most beginners expect. A compressor fridge, LED lighting, a water pump and a laptop can pull 40 to 60Ah in a single day. Without a recharge source, you are either driving around to top up or heading home early.
Solar fixes this quietly. While you hike, cook or sleep, the panels keep feeding the battery. The benefits stack up:
- Freedom from hook-ups. You can stay on wild pitches, public land and quiet aires without paying for power.
- No engine idling. You save fuel and avoid annoying your neighbours.
- Low running cost. After the upfront spend, the energy is free.
- Longer battery life. A steady trickle charge is gentler than repeated deep discharges.
For anyone travelling more than a few weekends a year, solar usually pays back within a couple of seasons.
Rigid, Flexible or Portable: Which Panel Type Fits Your Van?
Choosing the panel type is the first big decision, and each type suits a different van and lifestyle.
| Feature | Rigid | Flexible | Portable/Folding |
|---|---|---|---|
| Typical lifespan | 20+ years | 5 to 10 years | 5 to 10 years |
| Cost per watt | Lowest | Highest | Medium |
| Weight | Heavier | Very light | Moderate |
| Heat performance | Best (air gap) | Weakest | Good |
| Best for | Most vans | Curved roofs, weight limits | Shaded or crowded roofs |
Rigid panels use monocrystalline cells in an aluminum frame. Mounted on small brackets, they leave an air gap underneath that keeps them cooler and more efficient. A 100W rigid panel costs about £90 to £150 in the UK or $100 to $180 in the US.
Flexible panels bend to fit curved roofs and add almost no weight, which helps if you are close to your payload limit. Because they are bonded flat to the roof, heat builds up and can shorten their life.
Portable panels sit on the ground and follow the sun, which makes them ideal when a tree or roof rack shades the van. The catch is setup time and theft risk. Many full-timers fix a roof panel and carry a portable one as a bonus.
Choosing the Right Wattage for Your Campervan Solar Setup
Buying on a hunch is the quickest route to a battery that still runs flat by Sunday evening.
Step 1: Make a list of everything you plug in
For every appliance, take its power rating and multiply it by the number of hours it runs in a normal day. Here is a typical example for two people:
| Device | Daily use |
|---|---|
| 12V compressor fridge | 400Wh |
| LED lights | 50Wh |
| Laptop | 100Wh |
| Phone and camera charging | 30Wh |
| Water pump | 20Wh |
| Total | 600Wh |
Some energy is always lost as heat in the cables and controller, so add a one-fifth safety margin and your target comes to about 720Wh daily.
Step 2: Work out how much energy your panel can really deliver
A handy formula is:
Daily Wh = rated watts × hours of strong sunlight × 0.75 (real-world efficiency factor)
The 0.75 covers real-world losses. Using this formula, a 200W panel gives about 675Wh on a bright summer day in southern England (around 4.5 peak sun hours). In December, with under one peak sun hour, the same panel might produce only 120Wh.
Step 3: Size for your worst month
This is where most buyers go wrong with solar panels for a campervan. A van that travels through dull northern winters, such as in Scotland or Washington State, needs a noticeably bigger array than one parked under the strong sun of Arizona or Texas. A rough starting point:
- 100W: weekend trips, light use, small fridge or none
- 200W: fridge plus gadgets in spring to autumn
- 300 to 400W: full-time living or winter travel
If your winter numbers look impossible, do not panic. Many owners add a DC-DC charger so the alternator tops up the battery while driving, then let solar handle the rest.
Essential Add-Ons: Charge Controller, Leisure Battery and Wiring
Panels alone do nothing. They need three supporting components.
MPPT vs PWM charge controllers
Never wire a panel directly to a battery. The controller sits between panel and battery, managing the flow of electricity so the battery is never overcharged or damaged.
- PWM: cheap and simple, fine for a single 100W panel.
- MPPT: costs more but harvests up to 30% extra energy, particularly in cold, cloudy or low-light conditions. For most vans above 100W, MPPT is the smarter spend.
Lithium or AGM?
LiFePO4 (lithium) batteries accept charge quickly, are lighter and allow deeper discharge. AGM batteries cost less upfront but are heavier and need more capacity for the same usable energy. If budget allows, lithium is the better long-term partner for solar.
Cable and fusing
Use cable rated for your current, fit an inline fuse close to the battery and keep runs as short as you can. Undersized cable causes voltage drop and wastes the energy you worked hard to collect. It is also a fire risk, so this is not the place to save pennies.
How to Install Solar Panels for a Campervan Safely
- Plan the layout. Measure the roof, mark vents and skylights, and check for shade from roof bars or ladders.
- Test before you stick. Lay the panel in position and check the cable route from roof to controller.
- Mount firmly. Use brackets with a roof-safe adhesive such as Sikaflex, or a proper roof-rack system.
- Seal everything. Any drilled hole must be sealed against water. Use a roof cable gland rather than squeezing wires through a window seal.
- Connect in the right order. Start by wiring the battery to the controller, and only then attach the panel leads. Reverse this order when disconnecting.
- Check after the first trip. Look for loose brackets, chafed cables and warm connectors.
Having a second person makes the whole job faster and safer.
Solar Panels for a Campervan: UK and US Costs
| Item | UK | US |
|---|---|---|
| Full 200W kit (panel, MPPT, cable, brackets) | £250 to £450 | $300 to $550 |
| Professional installation | £150 to £300 | $200 to $400 |
| Lithium battery (100Ah) | £250 to £600 | $300 to $700 |
Prices are typical ranges and vary by brand and retailer.
Neither country requires a licence for a standard 12V system, but two checks are worth making. In the UK, tell your insurer about the modification, as some require it to be declared. In the US, confirm roof load limits and warranty terms with your van’s manufacturer.
Common Mistakes to Avoid
- Sizing the system for summer only
- Choosing thin cable to save money
- Skipping the fuse
- Ignoring shade from a single roof vent, which can cut output sharply
- Mixing panels of different voltages without checking compatibility
Final Thoughts
Solar will not run an air conditioner or an electric kettle all day, but it handles fridge, lighting and devices reliably and silently. Start by writing down what you use, size for your toughest month, pair the panel with an MPPT controller and install it carefully. Do that, and a good set of solar panels for a campervan will give you power for many years of trips.
FAQs
How many watts do I need to run a campervan fridge?
Most 12V fridges use 300 to 500Wh a day. A 150 to 200W panel with a decent battery typically covers this in summer with solar panels for a campervan.
Do solar panels work on cloudy days in the UK?
Yes, but at reduced output, often 10 to 25% of rated power. An MPPT controller helps you get the most from weak light.
Can I fit solar panels myself?
If you are comfortable with basic 12V wiring, yes. Use proper fuses, seal the roof well and consider having an auto-electrician inspect the work.
Are rigid or flexible panels better?
Rigid panels are cheaper per watt, run cooler and last longer. Flexible panels make sense for curved roofs or tight weight limits.
How much do solar panels for a campervan cost?
A 200W kit is roughly £250 to £450 in the UK and $300 to $550 in the US, before installation.
How long do campervan solar panels last?
Quality rigid panels often last 20 years or more, losing around 0.5% of output per year, which makes solar panels for a campervan a long-term investment.
Can solar charge my battery while the van is parked in a garage?
Not effectively. Panels need daylight, so for storage use a small maintenance charger or a mains-powered trickle charger.
