More and more motorhome owners want to travel independently - without always having to rely on camping grounds with a power connection. A popular solution for this is a solar system. But what exactly is it? And how much does it really help?
What is a solar system for motorhomes?
A solar system is like a small power station on the roof of your motorhome. It consists of:
- Solar panels: These capture sunlight and convert it into electricity.
- Charge controller: It ensures that the current flows safely and appropriately into the battery.
- Battery: The electricity is stored here so that you can use it later.
How does this benefit you in practice?
You can stand freely, e.g. at the lake, in the mountains or on a pitch without a power connection. You always have power for lights, mobile phone, laptop, refrigerator, etc. You save fuel because you don't have to keep the motor running. You are travelling quietly and environmentally friendly - no generator required.
How much electricity does a solar installation really generate?
One example: A 200 watt solar panel can theoretically generate around 1,000 watt hours (Wh) of electricity on a sunny day. This corresponds to about 80-85 % charge of a 100 Ah battery (at 12 volts).
Please note: These values only apply under ideal conditions - i.e. in full sun, optimised orientation and without any power consumption during the charging time. In practice, this is rarely realistic, as consumers such as refrigerators, lights or chargers often run while the battery is charging. This means that some of the electricity generated goes directly into consumption and not into the battery.
What influences the actual performance?
- Weather: Clouds, rain or winter sun significantly reduce performance.
- Shadow: Trees, buildings or roof structures can reduce the solar output to almost zero.
- Alignment: Flat-mounted panels supply less current than optimally aligned ones.
- Simultaneous consumption: Electricity is often used directly before it can be stored.
- Technical losses: Cables, regulators and the battery itself "lose" some energy.
Realistic daily output in Germany (200 watt module)
The electricity generated by a 200 watt solar installation in Germany varies considerably depending on the weather conditions:
- Sunny (summer): Power generation approx. 800 to 1,000 watt hours, battery charge approx. 65 to 85 % of a 100 Ah battery
- Partly cloudy: Power generation approx. 300 to 600 watt hours, battery charge approx. 25 to 50 %
- Cloudy/winter: Power generation approx. 100 to 300 watt hours, battery charge approx. 10 to 25 %
Solar system vs. alternator - which charges better?
Both systems - solar installation and alternator - have their place in the motorhome. But they work differently and also supply different amounts of electricity.
Alternator - strong, but dependent on the motor:
- Delivers 30-100 amps per hour, depending on the vehicle.
- A 100 Ah battery can be almost completely charged in 1 hour of driving.
- Only works when driving.
- Consumes fuel and is not quiet.
Solar system - quiet, free, but weather-dependent:
- Delivers 2-5 amps per hour in good conditions.
- Also works when stationary, quietly and free of charge.
- Performance depends heavily on weather, orientation and consumption.
Conclusion for end users
No matter how much electricity your solar installation generates, it is always worthwhile. But remember: Depending on your consumption, you shouldn't expect there to always be an abundance of electricity, as you may be used to at home. Solar panels are a great way to live self-sufficiently, but they require realistic planning and conscious usage behaviour.
💡 Our tip
Care for your battery and clean the solar modules regularly to get the best out of your solar system. This means you are independent and enjoy longer self-sufficiency on your journeys.
This website uses automatic translations. Please excuse any errors. In case of doubt, the original German version applies.