What Size Solar Panel for Campervan UK?
This beginner-friendly UK guide explains how to choose the right solar panel size for a campervan. Learn what size panel suits weekends away, off-grid touring, fridge setups and typical 12V leisure battery systems.
Campervan solar panel sizes at a glance
This quick reference table shows the most common solar panel size ranges used in UK campervan conversions.
| Campervan Use | Typical Solar Size | Best For |
|---|---|---|
| Very simple weekend setup | 80W to 120W | Lights, USB charging, water pump |
| Weekend setup with fridge | 150W to 200W | Basic off-grid camping with light daily use |
| Regular touring | 200W to 300W | Fridge, lights, fan and device charging |
| More off-grid independence | 300W+ | Longer stays without driving or hook-up |
Simple answer: what size solar panel do most UK campervans need?
For many UK campervan builds, 150W to 200W is the most practical starting point.
- Enough for many weekend vans with a compressor fridge
- Useful balance between roof space, cost and charging performance
- Works well with common leisure battery systems
If the van only powers lights, phone charging and a water pump, a smaller panel may be enough. If you want longer off-grid stays, more solar is usually the better long-term choice.
What affects the solar panel size you need?
The right solar panel size depends on how much electricity you actually use each day and how often the van is driven.
- Whether you run a 12V compressor fridge
- How many days you stay parked without driving
- Battery size and battery type
- Season and UK weather conditions
- Available roof space
- Whether you also charge from alternator or mains hook-up
How much power does a campervan solar panel produce in the UK?
Actual solar output depends on season, weather, panel angle and shading. The table below shows realistic rough expectations for UK campervan use.
| Panel Size | Summer Output | Spring / Autumn | Winter Output |
|---|---|---|---|
| 100W | 25Ah to 40Ah per day | 10Ah to 20Ah per day | 2Ah to 6Ah per day |
| 200W | 50Ah to 80Ah per day | 20Ah to 40Ah per day | 5Ah to 12Ah per day |
| 300W | 75Ah to 120Ah per day | 30Ah to 60Ah per day | 8Ah to 18Ah per day |
Is 100W solar enough for a campervan in the UK?
100W can be enough for a very simple campervan setup, especially for summer trips and lighter daily power use.
- Fine for lights and phone charging
- Can support a water pump and small accessories
- May help maintain battery charge during short stays
- Often limited for compressor fridge use year-round
For many people, 100W works best as a basic or entry-level solar setup rather than a full off-grid solution.
Is 200W solar enough for a campervan?
200W is one of the most sensible solar sizes for a typical UK campervan conversion.
- Good match for many vans with a fridge and leisure battery
- Offers more useful charging margin during mixed weather
- Often fits realistic roof space limits
- Usually feels much more practical than 100W in daily use
For many conversions, 200W is the point where solar starts to feel genuinely useful rather than just helpful.
Do you need 300W or more?
Panels in the 300W+ range make sense when you want stronger off-grid performance and more charging margin.
- Longer periods parked without driving
- Higher daily usage
- Better performance buffer during dull UK weather
- Larger battery banks
This can be an excellent option if roof layout allows it, but the system should then be matched with suitable cable size, fuse protection and a correctly rated solar charge controller.
Solar panel size vs leisure battery size
Solar size and battery size should work together. A very large battery with very little solar can take too long to recharge, while a large solar setup on a tiny battery may not make the best use of available roof space.
| Leisure Battery Size | Suggested Solar Size | Typical Use |
|---|---|---|
| 100Ah | 100W to 200W | Simple weekend setups |
| 150Ah | 150W to 300W | Fridge, lights, fan and charging |
| 200Ah+ | 200W to 400W | More regular off-grid use |
Rigid vs flexible solar panels for campervans
Both rigid and flexible solar panels are used in campervan builds, but they suit different installation styles.
| Panel Type | Best For | Typical Advantage |
|---|---|---|
| Rigid solar panels | Most campervan roofs | Better airflow and often longer life |
| Flexible solar panels | Curved or low-profile installs | Lighter and easier for some roof shapes |
Rigid panels are usually the more common and durable option for standard UK campervan conversions.
What size solar charge controller do you need?
The controller must be matched to the total panel current and system voltage. In most campervans, an MPPT controller is the preferred choice because it generally performs better than PWM in mixed conditions.
- Small systems may use a lower-rated controller
- Larger panel arrays need higher current controller ratings
- Always check panel specs, not just total wattage
- Leave some headroom rather than sizing too tightly
Is campervan solar enough in winter in the UK?
In many cases, solar alone is not enough in winter for a UK campervan that uses a fridge, fan and regular daily charging.
- Days are shorter
- Sun angle is lower
- Cloud cover is more frequent
- Panel output can fall sharply
That does not mean solar is pointless in winter, but it often works best as a support charging source alongside alternator charging or mains hook-up.
Roof space matters as much as wattage
Solar size is not just about power. It also depends on what can physically fit around vents, roof fans, skylights and roof racks.
- One larger panel can simplify wiring
- Two smaller panels may fit awkward roof layouts better
- Panel placement can affect shading and output
- Even partial shading can reduce real-world performance
What else do you need besides the solar panel?
A campervan solar system also needs several supporting parts to work safely and efficiently.
- Solar charge controller
- Correctly sized cable
- Fuse protection
- Roof gland and mounting brackets
- Leisure battery
If you increase panel size, make sure the controller and wiring are matched correctly.
What size solar cable do you need for a campervan solar panel?
Choosing the correct solar cable size is essential for safe charging performance and reducing voltage drop between the panel and the charge controller.
In most UK campervan solar systems, the correct cable size is either 4mm² or 6mm² PV cable, depending on panel power and cable length.
Solar cable size / voltage drop diagram
panel → cable run → controller, with 4mm² vs 6mm² comparison
| Solar Panel Size | Typical Cable Size | Notes |
|---|---|---|
| Up to 150W | 4mm² | Suitable for short cable runs |
| 150W to 300W | 6mm² | Most common campervan setup |
| 300W+ | 6mm² to 10mm² | Depends on cable length |
4mm vs 6mm solar cable for campervans
Both 4mm² and 6mm² solar cable are commonly used in campervan installations, but they suit slightly different setups.
| Cable Size | Best Use Case | Typical Install Example |
|---|---|---|
| 4mm² solar cable | Short panel-to-controller runs | Single 100W panel roof installs |
| 6mm² solar cable | Longer cable runs or larger panels | 150W to 300W campervan systems |
For most UK campervan builds with a compressor fridge and 150W to 300W solar, 6mm² cable is the safest and most future-proof choice.
Why solar PV cable is different from normal 12V cable
Solar panel wiring should always use dedicated photovoltaic cable rather than standard automotive cable.
- Designed for outdoor UV exposure
- Double insulated for safety
- Suitable for high DC voltage systems
- Flexible tinned copper conductors
- Halogen-free insulation for safer installations
Recommended solar cable for campervan installations
For most campervan solar panel installations, either 4mm² or 6mm² PV cable provides excellent performance and safe charging efficiency.
- 4mm² works well for short cable runs from smaller panels
- 6mm² reduces voltage drop in larger systems
- Both sizes support typical MPPT controller setups
See available cable options here:
Helpful calculators for campervan solar wiring
Related campervan electrical guides
Choose solar panel size before buying the rest of the system
The right panel size makes battery charging easier, improves off-grid performance and helps you choose correct cable, fuse and controller sizes from the start.
Open Electrical CalculatorsElectrical installation safety notice
This guide and the associated calculators are provided for general educational purposes only. They show typical sizing logic and estimation methods commonly used in UK 12V campervan electrical systems.
Every campervan installation is different. Solar panel output, cable sizing, fuse selection, battery capacity and charging equipment should always be checked against manufacturer specifications and the requirements of your specific vehicle.
Where high-current battery systems, DC-DC chargers, inverters or 230V mains hook-up equipment are involved, installation should be completed or inspected by a suitably qualified installer.