December 18, 2025

Solar power is one of the most common upgrades people consider when building or buying a campervan. Many owners ask the same questions, such as:

• How many solar panels do I need? 
• Will solar keep me fully off grid?
• Is a bigger system always better? 

The reality is that the right campervan solar panel setup depends far more on how you use your van than on chasing the highest wattage possible. A well matched system can keep things simple, reliable and cost effective, while an oversized or poorly planned one can still leave you short on power when you need it most. 

This guide explains how campervan solar works, what different panel sizes realistically deliver in UK conditions, and how to think about solar, batteries and usage together so you end up with a setup that suits your travels.

At a basic level, a campervan solar system captures energy from sunlight and stores it so you can use electricity when the sun is not shining. The system is made up of four main parts. The campervan solar panel collects energy from daylight and converts it into electricity. This electricity passes through a solar charge controller, which regulates how power flows into your battery and prevents overcharging. Most modern systems use MPPT technology, which is more efficient and better suited to variable UK light levels. The battery then stores that energy so it can be used to power lights, fridges, charging sockets and other equipment. Solar works best as part of a wider electrical system. It is designed to maintain and top up your battery rather than instantly power everything on its own. Understanding this relationship is key to choosing the right setup.

One of the biggest mistakes people make is focusing purely on solar panel wattage without thinking about how much power they actually use. Two vans with the same panel can have completely different experiences depending on what is being powered inside.

If you mainly use your van for weekend trips, running lights, charging phones and keeping a fridge cold, your daily consumption is relatively low. If you work remotely, use laptops, inverters, diesel heaters or spend days parked without driving, your demand is much higher.

Solar has to replace what you use each day. If your usage exceeds what your panels can realistically generate over time, your battery will slowly drain regardless of how large it is.

Try our simple solar system calculator to find out an estimate of what you may need for your campervan solar system:

Many campervan solar kits are based around familiar panel sizes, most commonly 100W and 200W panels. These numbers refer to peak output under ideal conditions, not what you will see all day, every day.

A single 100W campervan solar panel is often enough to support light usage. It can comfortably maintain a battery for weekend trips, basic lighting, phone charging and running a 12V fridge in summer when daylight hours are long. It is a popular choice for smaller vans with limited roof space or owners who travel seasonally.

A 200W setup offers a noticeable step up. It provides more consistent charging across the day and gives better resilience during overcast weather. This size is well suited to people who spend longer off grid, use their van more frequently, or want extra headroom for cloudy days without immediately jumping to a complex system.

Larger setups using multiple panels are possible, but beyond a certain point battery capacity and roof space become the limiting factors rather than panel output alone.

Panel type matters just as much as wattage. Many campervans use semi flexible or CIG solar panels because they suit curved roofs and low profile builds.

A flexible solar panel campervan setup keeps weight down and avoids drilling large mounting frames into the roof. Modern CIG panels are more efficient than standard flexible panels, cope better with heat, and handle partial shading more effectively. They are well suited to campervans where aesthetics, height restrictions or roof layouts make rigid panels impractical.

Rigid panels can offer excellent performance, but they require mounting brackets, ventilation gaps and more roof real estate. The best choice depends on the van, not just the numbers on the panel.

Solar panels generate power, but batteries determine how long you can actually use it. A common issue is installing solar without enough battery capacity to store what the panels produce.

Traditional AGM batteries are still widely used and work well for basic systems. Lithium batteries, particularly LiFePO4, store more usable energy, charge faster and cope better with deeper discharge. This makes them especially effective in off grid campervan power setups where solar is doing most of the work.

A large solar array with a small battery wastes potential, while a large battery with insufficient solar may never fully recharge. Balance matters.

UK weather plays a major role in solar performance. Summer days are long and even moderate systems perform well. Winter days are short, light levels are lower and solar output drops significantly.

This does not mean solar is ineffective, but expectations need to be realistic. Solar is best seen as part of a system that may also include vehicle charging, mains hook up or portable power options depending on the season.

Being fully off grid year round is possible, but it requires careful system design and realistic usage planning.

For weekend trips and holidays, a modest solar setup paired with a sensible battery is often more than enough. Driving between stops helps top up the battery, and solar keeps everything ticking over while parked.

For longer off grid stays, a larger panel setup and lithium battery provide more resilience, especially when parked for several days without moving. Efficient appliances make a big difference here.

For remote working, solar becomes more demanding. Laptops, routers and chargers quickly increase daily usage, and solar needs to be sized accordingly or supported by other charging methods.

Portable options such as off grid power stations can complement a fixed system. They are useful for occasional high demand, outdoor use or vans where roof space is limited. They can also provide flexibility for people who do not need a permanent large system.

These solutions are not a replacement for a well designed fixed setup in most cases, but they can fill specific gaps effectively.

If your setup is simple, many basic solar kits work well. As systems grow more complex, professional design becomes more valuable. Matching panels, charge controllers, batteries and usage avoids wasted money and poor performance.

A properly planned campervan solar kit should feel invisible in use. When it is right, you stop thinking about power and simply enjoy the van.

If you are unsure what size solar setup you really need, or want advice on designing a reliable off grid campervan power system, speak to Templer Way Campers. Whether you are planning a new conversion or upgrading an existing van, expert guidance can help you get the most from your solar investment and enjoy stress free travel.