Solar is your most important charging source when free camping. It works silently, costs nothing to run, and replenishes your batteries every day without driving anywhere. But solar has limitations that catch new caravanners off guard: it doesn’t work at night, output drops dramatically on cloudy days, and the rated wattage on the panel is almost never what you actually get. Understanding how your solar system works helps you set realistic expectations and get the most from your panels.
How Solar Works In Your Caravan
Solar panels convert sunlight into DC electricity. That electricity passes through a solar controller (also called a regulator) which manages the voltage and current flowing into your house batteries. The controller prevents overcharging and optimises the charge rate based on battery condition. Your batteries then store the power for use whenever you need it.
The key components are: panels (mounted on the roof, portable, or both), the solar controller (PWM or MPPT, mounted inside the van), and cables connecting everything together. It’s a simple system with no moving parts, which means very little can go wrong mechanically.
Panel Types & Output
Roof-mounted panels: Permanently installed on the roof. Convenient because they work automatically with no setup, but they only generate power when the van’s roof is in direct sunlight. If you park under a tree for shade (which you will in summer), roof panels produce very little. The Redarc 200W monocrystalline panels are the premium choice for Australian conditions, with Enerdrive and Renogy offering solid alternatives at lower price points. Most factory-fitted panels are 150 to 200W; upgrading to 300 to 400W total is a common early modification.
Portable panels: Foldable panels (typically 120W to 200W) that you set up on the ground and angle towards the sun. They can be positioned in full sunlight even when the van is in shade. The downside: they need to be set up and packed away, they can be stolen, and they take up storage space. The Redarc 200W Folding Panel ($500 to $600) is the benchmark for quality. The Renogy 200W Folding Kit ($300 to $400) and Kings 250W ($200 to $300) offer good value at lower price points.
Most effective setup: Roof-mounted panels for everyday passive charging, supplemented by a portable panel for shade camping. This combination covers the widest range of camping scenarios.
Rated Output vs Real Output
A “200W” panel produces 200W only under perfect laboratory conditions (direct sunlight, 25°C panel temperature, zero shading). In the real world, expect 60 to 80% of rated output. A 200W panel realistically produces 120 to 160W during peak sun hours. In winter, on cloudy days, or with partial shading, output drops further. Factor this into your calculations.
Solar Controllers: PWM vs MPPT
PWM (Pulse Width Modulation): The basic controller type. Works fine for small, simple systems. Typically found in budget caravans. Efficiency is adequate but not optimal, particularly in less-than-ideal conditions.
MPPT (Maximum Power Point Tracking): The premium controller type. More efficient, extracting 10 to 30% more power from the same panels compared to PWM. This efficiency gain is most noticeable in cloudy conditions, early morning, and late afternoon when panel output is lower. The Victron SmartSolar range ($150 to $300) offers Bluetooth monitoring and is the most popular aftermarket choice. The Redarc MPPT regulators ($200 to $350) are another excellent option, particularly as part of a Redarc system. If you’re upgrading or choosing a controller, MPPT is worth the extra $100 to $200.
How Much Solar Do You Need?
This depends on your daily power consumption and how much time you spend free camping.
100 to 200W: Adequate for couples who stay at powered sites regularly and only free camp for 1 to 2 nights between parks. Keeps batteries topped up but won’t sustain heavy off-grid use.
200 to 300W: The sweet spot for most couples who free camp regularly. Covers basic to moderate consumption (lights, fridge, phones, water pump) with comfortable margins.
300 to 400W+: Recommended for families, remote workers, or anyone planning extended free camping. Provides enough input to sustain higher consumption and recover from cloudy days.
Peak sun hours vary across Australia: roughly 4 to 5 hours in southern states during winter, 6 to 8 hours in the north year-round. A 200W panel producing 150W for 5 peak hours generates 750Wh (about 62Ah at 12V). Compare that to your daily consumption to see if your solar covers your needs.
Getting The Most From Your Solar
Keep panels clean. Dust, bird droppings, and grime reduce output by 10 to 25%. A quick wipe with a damp cloth when you set up camp makes a measurable difference.
Angle portable panels towards the sun. Panels angled directly at the sun produce up to 25% more than panels lying flat. Adjust angle through the day if you’re around camp.
Park strategically. If your only solar is roof-mounted, park with the roof in sunlight and the living side in shade (use your awning for shade). If you have portable panels, park wherever you like and position the panels separately.
Monitor input. Your solar controller or battery monitor should show how much solar power is coming in. If output seems low, check for shading, dirty panels, or controller issues.
- Expect 60 to 80% of rated panel output in real-world conditions. A 200W panel realistically produces 120 to 160W.
- MPPT controllers extract 10 to 30% more power than PWM. Worth the upgrade.
- 200 to 300W suits most couples. 300 to 400W+ for families and remote workers.
- A combination of roof-mounted and portable panels covers the widest range of camping scenarios.
- Keep panels clean and angled towards the sun for maximum output.
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