Van life

A Free Guide to DIY Solar Panels on Your Van Conversion

Van life has exploded in popularity in recent years, with more and more people converting vans into campers and living a life on the road. Going for DIY solar panels on your van can provide the energy you need to power lights, appliances and devices while off-grid. Doing it yourself rather than hiring a professional will save you quite a bit of money on labour costs.

In this DIY guide, we’ll cover everything you need to know to successfully install solar panels on your campervan conversion. We’ll discuss where to purchase quality solar components in the UK, the complete list of parts you’ll need for the solar system, step-by-step instructions for mounting the panels and wiring up the system, and important safety considerations to keep in mind. By the end, you’ll have the knowledge to harvest renewable solar energy to power your off-grid adventures in your self-converted campervan.

Determining Solar Panel System Size:

When installing DIY solar panels for your campervan, it’s important to properly size your system to meet your electricity needs. Here’s how to work out the right solar panel and battery bank capacity:

  • Calculate total watt-hours per day needed. Make a list of all electronic devices and appliances you want to run. Look up the wattage and estimated daily runtime for each and multiply to get watt-hours per day.
  • Factor in days without sun. Size your system to meet needs even with 2-3 days without sunlight by multiplying your total watt-hours per day by 2 or 3.
  • Choose solar panels. Determine the peak wattage by dividing your total watt-hours by the average peak sun hours per day for the UK (3). Select panels that meet or exceed this wattage.
  • Calculate battery bank amp-hour capacity. Multiply your total watt-hours per day by 1.3 to allow for depth of discharge. Then divide by 12V to get the minimum amp-hour rating needed for the battery bank.
  • Select inverter wattage for AC appliances. Make sure your inverter can handle peak combined wattage of all AC devices to be powered.

Correctly sizing your solar system will ensure you have enough power for your needs without overspending. Consider starting smaller and adding panels over time as your power demands increase.

Here is an example for calculating solar panel and battery size for a van conversion:

Let’s say you want to power the following appliances in your van (this is just an example demonstrating how to calculate size of system, figures used may not be accurate):

  • LED lights (10 x 3 watts each) = 30 watts
  • MaxxAir fan = 8 watts
  • Laptop = 15 watts (20 start-up)
  • Phone charger = 5 watts
  • 12V portable fridge = 2 watts (15 watts initial start-up)
Estimated daily runtime:
  • Lights: 6 hours
  • Fan: 8 hours
  • Laptop: 3 hours
  • Phone charger: 3 hours
  • Fridge: 24 hours
  • Lights: 30 watts x 6 hrs = 180 Wh
  • Fan: 8 watts x 8 hrs = 64 Wh
  • Laptop: 15 watts x 3 hrs = 45 Wh
  • Phone charger: 5 watts x 3 hrs = 15 Wh
  • Fridge: 2 watts x 24 hrs = 48 Wh

Solar panel size:

Total = 352 Wh/day x 3 days = 1056 Wh

Peak watts = 1056 Wh / 3 hrs = 352 W

Go with 400W solar panels (4 x 100W panels)

Battery capacity:

1056 Wh x 1.3 = 1373 Wh / 12V = 115 Ah

Go with 2 x 100 Ah batteries = 200 Ah capacity

200W inverter for occasional AC use

Wiring diagram for DIY solar panel kit
Wiring diagram Credit Instructables

What You Will Need for your DIY solar panel kit:

Solar panels, mounting hardware, wiring, and several other components are required to complete your DIY solar panels camper installation. Here’s a full list:

Solar Panels:
  • Silicon monocrystalline or polycrystalline panels recommended for highest efficiency in smaller space.
  • Typical sizes are 50W, 100W, 150W. Can combine panels for desired total wattage.
  • Consider SunPower, Renogy, Rich Solar, WindyNation brands.
  • Purchase 25-30% more wattage than your calculated requirement.
Mounting System:
  • Aluminium Z-brackets like RV SnapPads or TiltR mounting brackets designed for campervans.
  • Low profile and angled to maximize solar exposure.
  • Stainless steel mounting hardware – bolts, washers, lock washers, nuts. Minimum M8 size.
  • 10 AWG copper wire for runs from solar panels to charge controller.
  • 6 AWG copper wire for battery bank connections.
  • MC4 connectors to link panels together.
  • DC rated split loom tubing to protect wires.
Charge Controller:
  • MPPT controller to maximize solar charging efficiency.
  • Minimum 80% of total solar wattage rating. Victron, Renogy, etc.
  • Display screen to monitor system. Optional Bluetooth/WiFi.
  • Remote display available.
  • Deep cycle AGM, Gel or Lithium LiFePO4 batteries.
  • Lithium is lighter, longer lasting, more expensive.
  • Size battery bank for calculated capacity needs.
  • Minimum 100Ah rating recommended. Can wire in parallel.

Lead-acid batteries – This includes deep cycle AGM and gel batteries used in RV and marine applications. They should only be discharged 50-80% to preserve battery life. Discharging to 50% gives the full rated capacity.

  • 100Ah AGM battery = 50Ah capacity if discharged to 50%
  • Must size bank 2x calculated capacity since can’t use full rating

Lithium batteries – Lithium iron phosphate (LiFePO4) can be safely discharged to 100% of rated capacity.

  • 100Ah lithium battery = full 100Ah capacity
  • Don’t need to oversize bank since you can utilize entire rating

This means if you need 200Ah battery capacity for your loads and solar system, you would need:

  • Lead-acid: 400Ah battery bank size
  • Lithium: 200Ah battery bank size

While lithium batteries have higher upfront cost, they last over twice as long as lead-acid and the usable capacity makes them ideal for off-grid solar needs. You save space, weight and cost over the system lifetime.

  • Pure sine wave inverter needed for sensitive electronics.
  • Size for 2-3x total AC wattage to be powered simultaneously.
  • Hardwired or plug-in options available.
  • Examples: GoPower, Xantrex, Krieger, Aims.

Specialty tools like a crimping plier, wire stripper, voltmeter and drill bits for mounting hardware will also be useful.

When wiring, connect panels through charge controller to batteries, and connect DC appliances directly to the batteries. The inverter can supply AC power as needed. Carefully size all components and use fuses or breakers.

Blue ford transit van converted to camper parked up next to lake

How to Install DIY Solar Panels on your Van: 

Installing solar panels on your campervan conversion is a complex but doable DIY project with proper planning and precaution. The key steps include mounting the solar panels securely to the roof or sides of the van, wiring the panels into the electrical system to charge the batteries, connecting appliances to be powered, and positioning the panels for maximum sunlight exposure. Taking the time to install each component of the system cleanly and effectively will ensure your solar setup will perform efficiently for years of off-grid power generation. Follow these step-by-step instructions carefully for a solar panel installation that you can rely on in your adventures.

The process will take some time and diligent work, but the end result will make powering your campervan appliances and devices from renewable energy possible. Gather your tools, materials, and safety gear. Here is a brief guide on installing your DIY solar panels, however we have included a link to a great YouTube tutorial we highly recommend watching.

Mounting the Panels:
  • Plan mounting locations on roof or sides of van to maximize sunlight exposure. Consider existing roof fixtures and leave room for access to roof.
  • Clean and prepare mounting locations for good adhesion. Remove any dirt or debris and wipe with alcohol to degrease the surface.
  • Use Z-brackets, tilt mounts or rails to secure panels in position. Mark and drill pilot holes for mounting hardware. Check measurements before drilling.
  • Apply sealant/adhesive to waterproof. Use RV sealant around brackets to prevent leaks. Bolt in place securely using stainless steel hardware.
  • If needed, attach tilt legs or actuators to panels to allow adjusting the angle for optimal sunlight capture.
Wiring the DIY solar panel system:
  • Run 10 AWG copper wires from each panel through knocked-out openings to the charge controller. Use MC4 connectors to link panels together in series or parallel.
  • Use flexible split loom tubing over wires for protection. Route wires neatly and secure in place with zip ties or clamps, avoiding sharp edges.
  • Connect the positive and negative wires from the solar array to the charge controller inputs. Install in-line fuses on all positive wires for safety.
  • Run 6 AWG copper wires from charge controller to batteries for battery bank connections. Fuse the positive wire.
  • Connect and test operation of the charge controller to regulate charging.
Wiring the appliances:
  • Run wires from battery bank to DC fuse panel and connect appliances. Use appropriate wire gauge for each device.
  • For AC powered appliances, connect inverter to batteries and link appliances to inverter AC outlets.
  • Label all wiring connections clearly for easy system maintenance.
Solar DIY van tutorial:
DIY solar set up by City Prepping
Safety Considerations:

Proper electrical wiring is critical for a safe solar installation. Use adequately sized wiring for all connections and install in-line fuses on the positive wires to prevent shorts and fires. Follow wiring diagrams precisely and make secure connections. Improper wiring can risk shock or damage.

Working on the roof of a vehicle brings risks of falls or injury. Use a ladder to access the roof safely and wear shoes with grip. Have someone support the ladder. Attach fall arrest ropes when working at heights. Only work in dry, wind-free conditions.

Remember to check your local regulations before installing solar panels. Some areas may require permits or have restrictions for DIY electrical work. Vehicles with solar may require additional inspection and certification. Improper installs can be hazardous and fail inspections.

  • Always disconnect the battery bank before working on the electrical system. Remove the main fuse or breaker feeding the batteries to isolate them. Also, cover solar panels or disconnect the array’s input so it does not feed in power unexpectedly.
  • Take the installation slow and get professional help if needed. Solar installations can be complex, so don’t rush through the process. If you feel unsure about any aspects, consult an experienced solar installer for guidance. Never take shortcuts or compromise on safety – the electrical and fall risks involved make safety the absolute top priority throughout the installation. Move step-by-step and ask for help when required prioritizing personal safety.

Where to Buy DIY Solar Panels UK:

One convenient option for sourcing your campervan solar system is to buy an all-in-one DIY solar panel kit. Renogy and Amazon UK both offer various pre-configured kits that include monocrystalline panels, a charge controller, wiring, mounts and instructions tailored to different power needs. For example, Renogy’s 200 Watt 12 Volt Solar RV Kit for £249is a great starter kit, but you will still need to buy a battery and other components.

Amazon sells similar bundles like the ECO-WORTHY 240 watt 12v Solar Kit for a similar price of £220, similar to Renogy’s kit above you will still need to buy the Battery and additional components. While pricier than buying individual components, these kits provide everything you need for a complete plug-and-play DIY campervan solar installation. Just mount the hardware, wire up the system following the manuals, and you’ll have renewable power generation up and running quickly.

Example kits available:
DIY solar panel kit from EcoWorthy 240w system

EcoWorthy 240w solar panel kit

Renogy's 600w DIY solar panel uk kit

Renogy 600w solar panel kit

Renogy 300w DIY solar panel kit

Renogy 300w Solar panel kit

What to Look for in Solar Panels:
  • Output power rating (watts) – Select monocrystalline panels from 100W to 400W based on your needs. More watts equals more power production.
  • Size – Standard sizes are 50x100cm up to 150x100cm. Measure your mounting area to ensure fit. Can install panels in series.
  • Efficiency rating – Monocrystalline panels are 15-22% efficient. Higher is better.
  • Voltage – 12V or 24V. Match voltage of your battery bank.
  • Current rating (amps) – Higher amps allow connection of more panels in parallel.
  • Certifications – Look for IEC 61215, IEC 61730, and UL 1703 certification. Indicates safety and reliability.
  • Brands – Go for reputable makes like Renogy, Eco-Worthy, HQST, WindyNation.
  • Warranty – 20-25 years on performance. At least 5 years on parts.
DIY solar panel kit Budget Example:
  • 400W Solar Panel Kit – £350 to £500
  • MPPT Charge Controller – £120
  • 2x 100Ah Lithium Batteries – £1200
  • DC-DC Charger – £90
  • Wires, fuses, mounts – £150

Total System Cost: Around £1910 to £2060

DIY Solar panels installed on top of white van


Adding DIY solar panels allows you to enjoy all the comforts of modern living while journeying off-grid in your campervan. With solar power, you can run lights, a refrigerator, laptop, phone chargers, fans, and other appliances just as you would at home. This gives you the freedom to travel anywhere without worrying about electric hook-ups or running noisy, polluting generators constantly.

The UK receives moderate sun exposure year-round, allowing properly-sized solar systems to harvest sufficient energy. A 400-600 watt solar array coupled with 200-300Ah of battery storage enables powering the same appliances and devices you’re accustomed to. Lighting, computing, communication, cooking, temperature control – solar energy provides it all.

Installing DIY solar panels yourself allows customizing the system to perfectly meet your energy needs for off-grid living. Additional panels can be added over time as needs grow. By generating your own power from the sun, you can enjoy true energy independence and carbon-free living while exploring the UK’s beautiful landscapes.

Solar energy takes campervan living to the next level. Investing in a DIY solar panel installation allows you to spend more time adventuring, less time worrying about electricity. The initial investment pays off in the long run through freedom and self-sufficiency. Follow this guide to build your own off-grid solar system and power your nomadic dreams!