Adding solar to your campervan is one of the best ways to spend longer off-grid without constantly worrying about your leisure battery. But one of the first questions most people ask is:
How much solar power does a campervan actually need?
There isn’t one perfect answer. A small weekend camper with a few lights and phone chargers has completely different requirements to a van running a compressor fridge, laptops and 230V appliances.
The best way to size your solar setup is to start with how much energy you actually use each day, then work backwards to find a suitable solar panel size.
In this guide, we'll explain how to do exactly that, with realistic examples for UK campervans.
How Much Solar Does a Campervan Need? The Short Answer
For many UK campervans, 200W to 400W of solar is a useful starting point.
As a general guide:
| Campervan Use | Suggested Solar |
|---|---|
| Light weekend use | 100–200W |
| Typical touring setup | 200–400W |
| Longer off-grid stays | 400–600W+ |
| High electrical demand | Requires individual system design |
A 100W or 200W setup may be perfectly adequate if you regularly drive or use campsite hook-up.
If you're running a compressor fridge, charging multiple devices and regularly spending several days off-grid, moving towards 300W–400W or more can provide considerably more flexibility.
However, simply fitting the biggest solar panel that will fit on your roof isn't necessarily the best approach.
You need to consider your daily power consumption, battery capacity, charging system, available roof space and when you use your campervan.
Step 1: Calculate How Much Electricity You Use Each Day
Before choosing your solar panels, work out approximately how much energy your campervan uses each day.
The basic calculation is:
Power (W) × Time Used (Hours) = Energy Used (Wh)
For example, imagine your campervan has the following daily consumption:
| Appliance | Approx. Daily Energy Use |
|---|---|
| Compressor fridge | 360Wh |
| LED lighting | 40Wh |
| Two phones | 30Wh |
| Laptop | 120Wh |
| Water pump & controls | 30Wh |
| Total | 580Wh |
It's important to remember that some appliances don't run continuously.
A 45W compressor fridge, for example, won't normally consume 45W every hour of the day. The compressor switches on and off depending on temperature, ventilation, thermostat settings and how often you open the fridge.
For planning purposes, if it effectively runs for around eight hours throughout the day:
45W × 8 hours = 360Wh
Our example camper therefore uses approximately 580Wh per day.
It's sensible to add some headroom for conversion losses and smaller loads you may have forgotten.
Adding roughly 15–25% gives us a planning figure of around:
700Wh per day
Now we have something useful to work with.
Step 2: Work Out Your Campervan Solar Panel Size
Solar panels are advertised using their rated wattage, but a 300W solar panel doesn't continuously produce 300W throughout the day.
Real-world solar production changes depending on factors including:
- Time of year
- Cloud cover
- Panel temperature
- Panel angle
- Shading
- Roof orientation
- Wiring and controller losses
For initial planning, you can use equivalent peak-sun hours to estimate the required array.
The basic calculation is:
Daily Energy Requirement (Wh) ÷ Peak-Sun Hours = Minimum Solar Array (W)
Using our example of approximately 700Wh per day, and planning around three equivalent peak-sun hours:
700Wh ÷ 3 = 233W
On paper, around 233W could replace the day's energy consumption.
In reality, you want some additional capacity to account for cloudy weather, heat, wiring losses and the fact that roof-mounted panels are rarely positioned at the perfect angle.
That makes something around a 300W-class solar array a much more comfortable starting point for this example.
What About Solar During a UK Winter?
This is particularly important if you're building a campervan in the UK.
You shouldn't assume that a solar setup capable of covering your requirements during long summer days will produce the same amount of energy throughout winter.
UK winter solar output can be dramatically lower than summer output.
Shorter days, a lower sun angle and prolonged cloudy weather can significantly reduce the amount of energy your panels generate.
If you intend to travel throughout winter, it's usually better to treat solar as one part of your charging system, rather than expecting it to provide all of your electricity.
Combining solar with a DC–DC charger for charging while driving and a suitable mains charger for hook-up gives you much greater flexibility.
What Size Solar Panel Is Best for a Campervan?
Here are some useful planning ranges.
100W–200W Solar
A smaller solar setup can work well for campervans with relatively modest electrical requirements.
This could include:
- LED lighting
- Phone charging
- Water pump
- Small 12V devices
- Modest compressor fridge use
It's particularly suitable if you drive regularly or frequently use campsite hook-up, meaning solar isn't your only way of charging the leisure battery.
200W–400W Solar
For many touring campervans, this is a useful range to consider.
It provides more capacity for things such as:
- Compressor fridge
- Phones and tablets
- LED lighting
- Water pump
- Laptop charging
- Fans and other 12V accessories
If you want to spend a few days parked without driving, the additional solar capacity can make a significant difference.
400W–600W+ Solar
Larger arrays start to make sense for people who spend longer periods off-grid or have higher daily electrical consumption.
They can also complement larger lithium leisure battery banks.
At this point, however, roof space becomes an important consideration.
Roof vents, skylights, aerials, roof racks and other equipment can quickly reduce the usable space available for solar panels.
What About Induction Hobs, Kettles and Electric Heating?
This is where things become more complicated.
High-powered appliances such as:
- Induction hobs
- Electric kettles
- Hairdryers
- Coffee machines
- Electric heaters
can consume a substantial amount of energy.
Solar can certainly help replace some of that energy, but these appliances need to be considered as part of the whole electrical system.
Your solar panels, leisure battery, inverter and charging equipment all need to work together.
Don't Forget the MPPT Solar Charge Controller
Your solar panels shouldn't be connected directly to your leisure battery.
A solar charge controller sits between the panels and battery and regulates the charging process.
For campervan installations, you'll commonly see MPPT (Maximum Power Point Tracking) charge controllers.
An MPPT continually seeks the operating point where your panels can deliver useful power and converts that power to the charging voltage required by your leisure battery.
But choosing an MPPT isn't simply a case of matching it to the wattage printed on your solar panels.
You also need to consider:
- Maximum solar open-circuit voltage (Voc)
- Panel configuration
- Series and parallel wiring
- Maximum controller output current
- Battery voltage
- Cold-weather panel voltage
This becomes particularly important when multiple panels are connected in series because their voltages add together.
Always make sure your planned solar array remains within every limit specified by the MPPT manufacturer.
Victron SmartSolar MPPT Controllers
For campervan solar systems, Victron SmartSolar MPPT controllers are a popular option.
The SmartSolar range includes built-in Bluetooth, allowing you to connect using the VictronConnect app.
This makes it possible to monitor information from your solar charger and configure compatible settings from your phone.
At Nomadic Leisure, we stock a range of Victron SmartSolar MPPT controllers, solar panels and the associated equipment needed to build a complete campervan solar system.
For smaller, appropriately sized arrays, options include the Victron SmartSolar MPPT 75/10.
The correct controller depends on your specific panel configuration, though, so don't choose an MPPT based purely on its name or headline current rating.
Rigid vs Flexible Solar Panels for Campervans
Another decision you'll need to make is whether to install rigid or flexible solar panels.
Rigid Solar Panels
Rigid framed panels generally offer a good combination of:
- Durability
- Airflow underneath the panel
- Value
- Straightforward replacement
They're a popular choice when you have suitable mounting space available on the campervan roof.
Flexible Solar Panels
Flexible panels can work well where a lower-profile installation is required or the roof shape makes a rigid panel difficult to install.
However, it's worth considering:
- Heat build-up
- Mounting method
- Long-term durability
- Replacement access
Neither type is automatically best for every campervan.
The important thing is choosing panels that fit your available roof space safely and avoid unnecessary shading.
Solar Panel Shading Matters More Than You Might Think
You could spend money building an impressive solar array and then significantly reduce its performance simply by installing it in the wrong place.
Common sources of shading include:
- Roof vents
- Roof bars
- Aerials
- Satellite equipment
- Roof boxes
- Stored equipment
Even partial shading can reduce panel performance.
When planning your campervan roof layout, think about where shadows will fall throughout the day rather than simply fitting panels wherever there happens to be a gap.
4 Common Campervan Solar Mistakes
There are a few mistakes worth avoiding when planning your system.
1. Choosing solar based purely on panel wattage
A 400W system isn't automatically better than a 300W system. Start by understanding how much energy you actually use.
2. Ignoring shading
Roof vents, racks and other equipment can create shadows across your panels and reduce their output.
3. Choosing the wrong MPPT
Always check the solar array's voltage and current against the charge controller's limits.
4. Expecting summer performance all year
A system performing brilliantly in July won't necessarily generate anywhere near the same amount of energy during a cloudy UK December.
Solar Is Only One Part of a Good Campervan Electrical System
A well-designed campervan doesn't necessarily rely on a single charging source.
Combining several charging methods gives you much more flexibility.
Solar panels provide quiet, automatic charging whenever suitable daylight is available.
A DC–DC charger can replenish your leisure battery whenever you're driving.
A mains charger or inverter/charger can recharge the system when you're connected to campsite hook-up.
Together, these systems mean you don't have to massively oversize one component to deal with every possible situation.
Your solar panels, MPPT, leisure battery, DC–DC charger and inverter should ultimately be considered as one electrical system.
Frequently Asked Questions
Is a 100W Solar Panel Enough for a Campervan?
It can be.
For a campervan with relatively light electrical use and regular driving or hook-up, 100W may provide a useful amount of charging.
If you're trying to reliably run a compressor fridge, charge several devices and remain parked for longer periods through variable UK weather, you'll probably want to consider more solar capacity.
Is 200W Solar Enough for a Campervan?
For many lighter touring setups, 200W can be a useful amount of solar, particularly when combined with alternator or mains charging.
Whether it's enough for your van depends on your daily energy consumption and the conditions in which you travel.
Is 300W Solar Enough for a Campervan?
A 300W solar array can be a good starting point for many UK touring campervans running a compressor fridge, lighting and everyday electronics.
As we've shown in our example, a campervan requiring around 700Wh per day could theoretically need around 233W using a three-peak-sun-hour planning assumption, making a 300W-class array a more comfortable target once real-world losses are considered.
Can I Connect a Solar Panel Directly to a Leisure Battery?
No. A correctly specified solar charge controller is required between the solar panels and leisure battery to regulate charging.
Will a Bigger Solar Panel Charge My Battery Faster?
Potentially.
More available solar power can increase charging speed, but only when sunlight conditions, battery acceptance, wiring and your charge controller all support the additional power.
Build the Right Solar Setup for Your Campervan
So, how much solar power does a campervan need?
For many UK builds, 200W–400W is a useful starting range, but the best solar setup isn't determined by a single number.
Start by calculating your daily energy consumption.
Then consider your battery capacity, available roof space, time of year, how long you stay off-grid and what other charging sources you have available.
That will give you a far better campervan electrical system than simply installing the biggest panel you can fit.
At Nomadic Leisure, we stock solar panels, cabling and Victron SmartSolar MPPT controllers for campervan electrical systems.
Need help matching your solar panels, MPPT, leisure battery and charging system? Explore our campervan solar range or speak to the Nomadic Leisure team about a bespoke electrical and solar design.
