Solar for Campervans, Motorhomes and Camping: A Complete Guide

Solar is one of the most practical upgrades you can make to a campervan or motorhome. Once installed, it generates free electricity from the sun — no hookup fees, no generator noise, no need to stay on campsites with electrical points. For wild camping and longer trips, it changes everything.

This guide covers how to size and spec a system for a van, motorhome, or camping setup — from panels and charge controllers to batteries and wiring.

Do You Need a Fixed or Portable Setup?

Before sizing panels and batteries, decide whether you want a permanent installed system or a portable one.

Fixed roof-mounted panels are ideal for full-time vanlifers, motorhome owners, and anyone doing extended trips. Panels stay on the vehicle, wiring is tidy, and you get consistent generation without setup effort at each stop.

Portable panels and power stations suit occasional campers, festival-goers, and people who want solar without drilling holes in their vehicle. You can take them camping, use them at home, and charge them on hookup overnight. No installation required.

For occasional camping, a portable power station like the EcoFlow DELTA or RIVER range paired with a folding solar panel is often the most practical solution — no wiring, no permanent installation, and you can use it at home too.

Sizing Your System

Step 1: Work Out Your Daily Power Needs

List everything you want to run and estimate how many hours per day:

This example represents a moderately loaded campervan. A basic setup (fridge, lights, phones) might be 500–700 Wh/day. A heavily loaded system with CPAP, multiple devices, and an inverter for 240V appliances could be 2,000+ Wh/day.

Step 2: Account for Solar Generation

In the UK, a solar panel generates roughly 3–4 peak sun hours per day on average (more in summer, less in winter). A 200W panel generates:

• Summer: 200W × 5 hours = ~1,000 Wh/day
• Spring/Autumn: 200W × 3.5 hours = ~700 Wh/day
• Winter: 200W × 2 hours = ~400 Wh/day (and often less due to lower sun angle and clouds)

Panels on a van roof are often not perfectly oriented — a flat-mounted 200W panel in summer might realistically generate 700–800 Wh/day.

Typical System Sizes

Panel Types for Vans and Motorhomes

Rigid Monocrystalline Panels

The standard choice for roof-mounted installations. High efficiency (20–22%), durable, and the cheapest per watt. The downside: they're rigid and need proper mounting frames. For a flat van roof, they work well; for a curved motorhome roof, flexible panels may be easier to install.

Typical cost: £80–£150 for a 200W panel.

Flexible Solar Panels

Thin, lightweight panels that can conform to curved surfaces. Popular for motorhomes with curved roofs. The trade-offs: lower efficiency, shorter lifespan (5–10 years vs 20+ for rigid), and they must be glued rather than mounted — heat builds up underneath, which can degrade the adhesive over time.

Typical cost: £100–£200 for a 200W flexible panel.

Portable Folding Panels

Foldable panels with carry handles, designed for placing on the ground or angling toward the sun. Perfect for camping rather than van installations. You can orient them optimally throughout the day, often generating more than a fixed roof panel.

Typical cost: £80–£200 for a 100–200W folding panel.

Charge Controllers: PWM vs MPPT

A charge controller sits between the solar panels and the battery, regulating charging to protect the battery from overcharging. There are two types:

PWM (Pulse Width Modulation)

PWM controllers are simple and cheap. They work by directly connecting the panel to the battery and reducing the connection duration as the battery fills. The downside: they force the panel to operate at battery voltage, not panel voltage. If your 200W panel has a Vmp (voltage at maximum power) of 36V but your 12V battery is at 12.5V, the panel is effectively clipped — you're wasting a significant portion of its potential.

PWM controllers make sense only for small systems (under 50W) where cost is the primary concern.

Typical cost: £15–£40.

MPPT (Maximum Power Point Tracking)

MPPT controllers continuously find the panel's optimum operating point (where it generates maximum power) and convert that to the correct voltage for the battery. This can recover 20–30% more energy from the same panel compared to PWM.

For any system over 100W, MPPT pays for itself quickly. A quality MPPT controller from Victron, Renogy, or EPever costs £50–£150 and will outperform a cheap PWM controller significantly.

Typical cost: £50–£200.

Battery Choices: LiFePO4 vs AGM

AGM (Absorbed Glass Mat) Lead-Acid

AGM batteries are the traditional choice for leisure vehicles. They're cheaper upfront, widely available, and don't require a BMS (battery management system).

The downsides are significant for van life:

• Usable capacity: Only 50% of rated capacity should be used regularly. A 100Ah AGM gives you 50Ah usable.
• Lifespan: 200–400 charge cycles if discharged to 50% regularly. That's 1–2 years of daily use.
• Weight: A 100Ah AGM weighs 25–30 kg.
• Charging: Needs specific charging voltages (bulk/absorption/float) and doesn't like partial charging.

Typical cost: £80–£150 for 100Ah AGM.

LiFePO4 (Lithium Iron Phosphate)

LiFePO4 batteries have transformed van builds in recent years. They're more expensive upfront but significantly better in almost every way:

• Usable capacity: 80–90% of rated capacity. A 100Ah LiFePO4 gives you 80–90Ah usable.
• Lifespan: 2,000–4,000 cycles. That's 5–10+ years of daily use.
• Weight: A 100Ah LiFePO4 weighs 10–13 kg — roughly half the weight of AGM.
• Charging: Accepts fast charging, fine with partial states of charge, no memory effect.
• Safety: LiFePO4 is the safest lithium chemistry — doesn't catch fire or explode if damaged.

For LiFePO4 cells, Fogstar is a well-regarded UK supplier stocking quality cells and complete batteries including their Drift and Robust ranges. Their cells are popular in the van life community for DIY battery builds.

Typical cost: £150–£300 for a 100Ah LiFePO4 battery; £200–£450 for 200Ah.

Wiring Basics

Van electrical systems run on 12V DC. Key principles:

Cable Sizing

Undersized cables get hot, waste energy, and are a fire risk. Use a cable sizing calculator or this rule of thumb:

Always fuse as close to the battery as possible. A short circuit in unfused wiring can cause a fire.

Fusing

Every circuit needs a fuse or circuit breaker rated for the wire, not the load. If you're using 6mm² cable (rated to ~40A), the fuse should be 40A or less.

Battery Isolator / Master Switch

Install a master isolator switch between the battery and the rest of the system. Essential for maintenance, emergencies, and when the van is in storage.

DC-DC Charger

A DC-DC (B2B) charger lets you charge your leisure battery from the vehicle's alternator while driving. Essential if you're doing winter trips or spending nights in locations with poor solar. Victron Orion-Tr Smart and Renogy range are popular choices. These replace older split-charge relays and work properly with modern smart alternators.

Portable Power Station Option

For occasional camping, a portable power station is often simpler than building a full van electrical system. Products like the EcoFlow DELTA 2 combine battery, inverter, BMS, and AC/DC outputs in one unit. Pair with a 200W folding solar panel and you have a complete off-grid power system with no wiring, no installation, and full portability.

The EcoFlow DELTA 2 has 1,024 Wh of capacity, 1,200W AC output, and charges from solar at up to 500W. It's substantial enough for most camping trips and can double as a home emergency power supply.

A Practical Starter System

For someone converting a van or adding solar to a motorhome for the first time:

This system will comfortably run a 12V compressor fridge, lighting, phone and laptop charging, and a 12V fan throughout spring, summer, and autumn in the UK.

Getting Help and Going Deeper

The UK van conversion community is active and knowledgeable. The Victron Community forum, DIY Solar Power Forum, and UK-specific Facebook groups like "Campervan Conversion UK" are excellent resources for system design help and real-world experience.

For LFP cells and complete batteries, Fogstar ships to UK customers and has good support documentation. Their Drift LiFePO4 batteries are popular for van builds due to their compact form factor and quality BMS.

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