Nothing is more environmentally friendly than solar energy. Modern photovoltaic solar panels use natural light and convert it into electricity. The more light there is, the more electricity there is, but even cloudy days produce electricity.

Solar panels are ideal for charging your leisure batteries in the summer, or for low-power devices such as alarms and trackers when a van has been in the warehouse for months.

They are also good news for those who leave the Internet. When you don't have a connection, they can provide enough current for your leisure battery to recharge. To sum up, solar panels are very effective, relatively cheap, easy to use, and environmentally friendly.

How do they work?
Photovoltaic solar panels are covered with a thin layer of silicon. When sunlight hits the panel, photons are absorbed, causing electrons to separate from silicon atoms and move around. This generates direct current, which is "collected" and guided by the controller to charge your leisure battery. Normally, RV solar panels generate an electric charge of 17-18V.

Types of solar panels for campervan
Silicon solar cells are currently available in three main types, which are known as monocrystalline, polycrystalline, and thin-film amorphous. Monocrystalline cells are made up of a single silicon crystal; polycrystalline comprise fragments of silicon.

The mono versions are more efficient because they allow electrons to move more freely, but they also tend to cost more. These crystalline panels work at efficiency levels of 15-20%.
Monocrystalline panel cells appear as a single, flat color; polycrystalline versions have grain and visible edges.

Thin-film panels use a completely different technology to that of mono and poly panels. At present, they are considered new tech and, while they are less efficient than the other two (except in low light), great advances are expected in the next decade.

Already, researchers have achieved 23.4% efficiency with them, although commercially available versions typically operate in the range of 10-15%.
Owing to their lower production cost, thin-film panels are expected to see the biggest growth in the future. These types of panels are flat-black in color.
Solar panels have an anti-reflective coating, which increases the absorption of sunlight, allowing the maximum amount to reach the silicon cells.

Freestanding panel.
Freestanding panels can be moved and used in different applications. They usually consist of two panels, hinged in the middle and folded into briefcase-style portable devices.
They can move throughout the day to maximize the angle of the sun, so they can be the most effective.

Rigid frame panel.
The rigid panels are flat, so they are very suitable for installation on the roof of the van, which optimizes exposure to the sun. They are strong and durable, but they are also heavy.
Heat accumulation reduces efficiency, so it's a good idea to leave a gap at the bottom of the panel to increase the cooling airflow. Panels installed on the roof should be cleaned regularly as any deposition of dirt or bird lime will affect its efficiency.

Flexible panel.
The thin and flexible panels are sturdy, lightweight, and low-key, and can be easily glued to the roof of an RV.
They are 100% waterproof, and some have a "self-healing" top layer that fills scratches and wear.

Select Panel.
Experts say that small differences in efficiency are not important, but that it is important to buy a respected panel brand with good manufacturing quality.
The warranty periods of solar panels vary from one to another. Some offer only a one-year warranty, but we recommend a five-year product warranty (especially for flexible panels). Some companies, such as International Solar Technology, provide their customers with a 20-year performance guarantee.
Glued panels are hard to remove, while framed, bolted ones can be moved to your next RV, but there will be holes to fill.
Many of the better panels will be IEC 61215 certified.