The Complete Buyers Guide To Caravan Solar Systems

Solar panels are the primary way most Big Lappers recharge their batteries while free camping. With no mains power and the engine off, solar is your only source of free, silent energy. The right solar setup can keep your batteries topped up indefinitely in good conditions, which means genuine independence from caravan parks and generators.

But solar has limits. Cloudy days, shade, winter sun angles, and dirty panels all reduce output. Understanding those limits and sizing your system accordingly is the difference between a solar setup that works and one that leaves you short.

How Caravan Solar Works

Solar panels convert sunlight into DC electricity, which is fed through a charge controller into your house battery. The charge controller regulates the voltage and current to safely charge the battery without overcharging it. The panels produce power whenever sunlight hits them, but output varies dramatically with conditions.

A 200W panel doesn’t produce 200W all day. That’s the peak rating under ideal laboratory conditions (direct noon sun, 25°C panel temperature, no shade). In the real world, you’ll get peak output for maybe two to three hours around midday, with lower output in the morning and afternoon. On a good sunny day in northern Australia, a 200W panel might generate 60 to 80Ah over the full day. In overcast southern Tasmania in winter, the same panel might produce 15 to 25Ah.

The practical rule for Australia: expect your solar panels to produce roughly 4 to 6 amp-hours per 100W of panel per day in good conditions. In winter or overcast weather, halve that.

Fixed Panels vs Portable Panels

Fixed (Roof-Mounted) Panels

Permanently mounted to your caravan roof, fixed panels are always connected and always working. You park, and they start charging. No setup, no cables to run, no adjustment needed. Most new caravans come with 160W to 400W of fixed solar on the roof.

Pros: Zero effort, always producing, can’t be stolen, don’t take up storage space.

Cons: Can’t be angled toward the sun (flat-mounted panels lose 15 to 30% efficiency compared to tilted panels), shaded when parked under trees (which you’ll want to do in summer), and output drops when the roof is hot (panel efficiency decreases as temperature increases).

Portable (Folding) Panels

Freestanding panels that you set up on the ground and connect to your van via an Anderson plug or similar. You can position them in full sun while the van sits in shade, angle them toward the sun for maximum efficiency, and move them throughout the day to follow the sun.

Pros: Can be positioned in sun while van is in shade, can be tilted for optimal angle, moveable throughout the day, supplement fixed panels.

Cons: Require setup and pack-up, take up storage space, can be stolen if left unattended, cables running across the campsite are a trip hazard.

The ideal setup for most Big Lappers is a combination: fixed panels on the roof for effortless baseline charging, supplemented by a portable panel for when you need extra input or when the van is parked in shade.

Solar Charge Controllers: MPPT vs PWM

The charge controller sits between your panels and your battery, regulating the charge to prevent overcharging and to maximise the energy harvested from your panels. There are two types:

PWM (Pulse Width Modulation): Basic controllers that essentially “switch” the connection between panel and battery on and off rapidly to regulate charging. They’re cheap ($30 to $80) and work, but they waste a significant portion of the panel’s potential output. A PWM controller typically harvests 65 to 75% of your panel’s theoretical output.

MPPT (Maximum Power Point Tracking): Advanced controllers that actively track the optimal voltage/current combination from your panels and convert it to the optimal charging voltage for your battery. They harvest 90 to 95% of your panel’s potential output, which translates to 15 to 30% more energy from the same panels compared to PWM. They’re more expensive ($150 to $500) but the extra energy harvested means you need fewer panels to achieve the same result.

For any system over 200W, an MPPT controller pays for itself in improved efficiency. For smaller systems (a single portable panel, for example), a PWM controller is adequate.

How Much Solar Do You Need?

The answer depends on your daily power usage and your battery capacity. As a starting point:

Light use (couple, LED lights, fridge, phone charging, no inverter): 50 to 70Ah/day. You need 200 to 300W of solar to replace this daily in good conditions.

Moderate use (couple or small family, fridge, lights, phones, occasional inverter use for coffee/laptop): 70 to 100Ah/day. You need 300 to 500W of solar.

Heavy use (family, fridge, lights, multiple devices, regular inverter use, TV, working remotely): 100 to 150Ah/day. You need 500W+ of solar, plus a generator or very large battery bank for overcast days.

These are guidelines for sunny conditions in most of Australia. If you’re travelling southern states in winter, increase by 30 to 50%. If you’re travelling the Top End in the dry season, you’ll have more sun than you know what to do with.

A practical approach: start with what your van has. Track your actual usage (a battery monitor makes this easy). If your batteries aren’t fully charged by mid-afternoon on a sunny day, you need more solar. Add a portable panel first; it’s the cheapest and most flexible upgrade.

Product Recommendations

Fixed Panels

Redarc 200W Monocrystalline: Australian-designed and extremely popular in the caravan market. High efficiency, slim profile, and well-suited to roof mounting. Redarc panels are fitted by many caravan manufacturers as standard. Around $350 to $450 per panel.

Victron BlueSolar 305W: A larger panel for vans with roof space. Victron’s build quality is excellent and the panel integrates seamlessly with Victron MPPT controllers. Around $350 to $450. Good value per watt for larger systems.

Enerdrive 200W Fixed: Another quality Australian-market panel. Pairs well with Enerdrive charge controllers and batteries. Around $300 to $400.

Portable Panels

Redarc 200W Folding Panel: The gold standard portable panel for caravanning. Folds in half, comes with an integrated stand for angle adjustment, and includes a 15A PWM controller in the carry bag (upgradeable to MPPT via a separate unit). Excellent build quality and a strong carry case. Around $600 to $750.

iTechworld 200W Folding Panel: A well-regarded alternative at a lower price. Good output, solid build, and includes a PWM controller. Around $350 to $450. Popular in the Big Lap community for its value.

Victron 175W Folding Panel: Slightly smaller but premium Victron quality. Pairs perfectly with Victron MPPT controllers. Around $500 to $600.

KickAss 200W Folding Panel: A budget-friendly option that performs reasonably well. The build quality isn’t at the Redarc or Victron level, but for the price it’s a solid starter panel. Around $250 to $350.

MPPT Charge Controllers

Victron SmartSolar MPPT 100/30: Handles up to 440W of solar (at 12V) with Bluetooth monitoring via the Victron Connect app. Highly efficient, reliable, and well-supported. The most recommended MPPT controller in the caravan community. Around $200 to $280.

Redarc MPPT Solar Regulator: Australian-made, available in various sizes to suit your system. Integrates with the Redarc RedVision monitoring system. Around $250 to $400 depending on capacity.

Enerdrive MPPT Controller: Quality unit that pairs with Enerdrive batteries and monitoring. Around $200 to $350.

Getting The Most From Your Solar

Keep panels clean. Dust, bird droppings, and grime reduce output noticeably. A quick wipe with a damp cloth every few days makes a measurable difference, particularly on outback roads where dust coats everything.

Angle portable panels toward the sun. A panel tilted toward the sun produces up to 30% more than the same panel lying flat. In winter, the sun is lower; increase the tilt angle. In summer, a flatter angle works. Most portable panels have adjustable legs for this.

Avoid shade. Even partial shade on one cell of a solar panel can reduce the output of the entire panel dramatically (not just the shaded cell). Park portable panels well clear of trees, awnings, and anything that casts a shadow.

Use an MPPT controller. If you’re still running a PWM controller, an MPPT upgrade harvests 15 to 30% more energy from the same panels.

Monitor your system. A battery monitor (like the Victron SmartShunt) shows you exactly how much solar is coming in and how much you’re using. This lets you make informed decisions about when to move panels, when to conserve, and when you’ve got plenty.