Solar modules and solar panels – not just for motorhomes

Yes, retrofitting a solar system to a motorhome is possible at any time, depending on the amount of free space available on the roof.

Depending on the model, you can attach solar panels to the motorhome roof using mounting spoilers or mounting profiles, or you can bond flexible modules to the entire roof surface. Foldable modules/solar bags, on the other hand, can be set up in just a few simple steps.

In general, the question depends on your requirements and on which vehicle, boat or for which area of application you would like to use it.

Flexible modules have the advantage that they can be adapted to your vehicle roof to a certain extent. They are also very flat, lightweight and walkable. The disadvantages are the low rear ventilation of the modules, which reduces the yield.

Framed modules are characterised by their durability, stability and relatively simple installation. The surface is resistant to mechanical influences such as hail or branches. Their disadvantage is their significantly higher installation height and greater weight compared to flexible modules.

Yes, you can still generate energy with your solar system in winter, but less than in the summer months. This is due to the lower position of the sun, shorter days and more frequent cloud cover. However, when the sky is clear, you benefit from higher module efficiency in cold weather.

In fact, it always depends on which modules you have installed on your roof and on the washing system itself. 

Please be sure to ask the car wash operator about this.

During installation, you must connect the solar panels to the battery system. To do this, you will need the appropriate mounting materials, weather-resistant cables, a roof feed-through, additional installation accessories and a solar charge controller.

We recommend DEKAsyl MS-5 – a high-quality single-component adhesive from the automotive industry that has been specially developed for recreational vehicles. It offers high initial strength for durable, elastic bonds and is ready to use immediately without mixing. This makes it the ideal choice for the secure and long-lasting installation of solar modules on motorhomes, campers and boat

The appropriate mounting method always depends on the vehicle in question and its area of application.

For panel vans or motorhomes that regularly travel at higher speeds, we generally recommend rear spoilers. They ensure stable, aerodynamic mounting and distribute the wind forces evenly across the roof surface.

Brackets, on the other hand, are more suitable for slower vehicles, trailers or stationary applications such as garden sheds.

In principle, people who are skilled at DIY can install solar modules themselves. However, this requires knowledge of bonding techniques, correct cable routing and electrical connections. It is particularly important to seal the roof penetrations professionally, as leaks can lead to moisture damage.

If you would prefer to leave the installation to professionals, we are happy to help! With over 20 years of experience, our workshop team ensures professional, durable installation that preserves all warranty claims.

Yes, installation on corrugated roofs (wavy roof surfaces) is possible with special adapter frames. These vehicle-specific frames compensate for the corrugations and create a flat mounting surface for the solar modules. The adapter frame is selected to match your vehicle model and installed together with a corresponding mounting kit. We would be happy to advise you on the right solution for your vehicle.

Yes, solar modules also generate electricity while driving, provided that sunlight falls on the modules. Electricity generation works regardless of whether the vehicle is stationary or moving. On the contrary: when driving, the modules can be cooled more effectively by the airflow, which slightly increases efficiency. However, make sure that the modules are securely fastened and can withstand high wind loads.

The actual yield depends heavily on location, season, orientation and weather. In Central Europe, you can expect 4-6 full load hours per day in summer and 1-2 hours in winter. A 200-watt module therefore delivers around 800-1,200 Wh per day in summer and 200-400 Wh in winter. In southern regions such as Spain or Portugal, yields are significantly higher. Shading, pollution and unfavourable orientation further reduce the yield.

The nominal power (e.g. 200Wp) is measured under standardised laboratory conditions (25°C module temperature, 1000 W/m² irradiation, vertical incidence of light). In practice, conditions differ: modules become significantly hotter in summer (power loss due to heat), the sun is not always at the optimum angle, and diffuse light reduces irradiation. Realistically, you can achieve 60-85% of the nominal power under good conditions.

Park your motorhome so that the solar panels are directly exposed to the sun. If parked in the shade, the batteries will charge more slowly. You should also always place a flexible solar bag in direct sunlight – and reposition it as necessary depending on the time of day.

Monocrystalline modules are made of high-purity, single-crystal silicon and can be recognised by their uniform dark colour. They achieve efficiencies of 18-22% and are more efficient, but also more expensive.

Polycrystalline modules consist of several silicon crystals, have a bluish colour and achieve efficiencies of 15-17%.

For mobile applications with limited roof space, we recommend monocrystalline modules, as they deliver more power for the same surface area.

Solar charge controllers for mobile and stationary systems operate using PWM or MPPT technology. Both types are generally suitable for charging the supply battery with solar energy.

MPPT charge controllers (maximum power point tracking) are more efficient and extract up to 20% more power from your solar modules than simple PWM controllers (pulse width modulation). They are therefore ideal especially in autumn and winter, as well as when the solar modules are not optimally aligned.

An MPPT charge controller is worthwhile in most cases, as it maximises the efficiency of the charging process. An MPPT solar charge controller should be used especially for solar systems on the roof of motorhomes or boats, where the greatest possible amount of energy needs to be generated in the smallest possible space.

The special feature of a bifacial module is its double-sided activity: unlike conventional solar modules, it not only converts direct sunlight on the front into electricity, but also uses the reflected and diffuse light from the environment via the transparent rear side. Diffuse light is light that is scattered by clouds or particles in the air and hits the solar cells. By capturing this otherwise ‘lost’ light, a significantly higher amount of energy can be produced on the same surface area.. 

Depending on the surface, this technological advantage leads to a considerable increase in yield of around 5% to 30% compared to single-sided modules. The technology is particularly efficient on light-coloured surfaces such as gravel or light-coloured roofing membranes, as these reflect light more strongly. 

First remove dirt such as fallen leaves and insects with clear water and a soft sponge, glass brush or microfibre cloth. It is best to clean in the morning or evening when the modules are cool – cold water on hot modules can cause stress cracks. Avoid aggressive cleaning agents, high-pressure cleaners or scratchy sponges, as these can damage the surface.

For stubborn stains, you can use mild washing-up liquid or car shampoo. Rinse thoroughly and avoid limescale marks by drying with a soft cloth.

High-quality solar modules have a service life of 25-30 years or more. Most manufacturers offer performance guarantees of 25 years with a guaranteed 80-85% of the original performance. The actual service life can be significantly longer – modules from the 1980s often still produce electricity. In mobile applications with vibrations and temperature fluctuations, the stress is higher, but modern modules are designed for this.

In the event of mechanical damage (cracks, breaks), the module should be disconnected from the system immediately, as moisture can penetrate and cause short circuits. Minor scratches have little effect on functionality. If there is a loss of performance without visible damage, first check the cabling and connections. Defective modules can often be replaced under warranty. Contact us or the manufacturer for a warranty check.

Important: Do not open or repair damaged modules yourself!

MC4® connectors are standardised, weatherproof connectors for solar systems designed for outdoor installation. They are UV-resistant, waterproof (IP67/IP68) and specially designed for high currents and voltages. Most modern solar modules are supplied with MC4® connectors. You will need compatible mating connectors or adapters to connect multiple modules and to connect to your charge controller. MC4® connections are the current industry standard and ensure secure, long-lasting connections.

Alternative plug types:

• MC3 connector: The predecessor of MC4®, still widely used in older solar modules. Similar properties to MC4®, but not directly compatible. MC3-to-MC4® adapters are available if you want to combine older modules with newer ones.
• Tyco/Amphenol H4 connector: Alternative to MC4®, technically equivalent and also widely used.
• Radox plug: Previously used by some manufacturers, but less common today. Robust construction, but proprietary and less standardised.
• Anderson PowerPole: Often used for connecting solar modules and charge controllers inside vehicles. Not suitable for outdoor installation.