The sun not only gives us life, it also continuously transmits energy to us on Earth. Can we convert this energy into electricity to power our electrical equipment? To achieve this, we need to use the solar panel device.
Solar panels, also known as solar panels, are devices that directly or indirectly convert solar radiation into electrical energy through the photoelectric effect or photochemical effect by absorbing sunlight. With it we can provide clean, quiet power to the RV and recharge the battery when the sun comes out. But before buying solar panels and modules, you should find out which type of solar panel is best for you.
In this article, we'll chat about the types of RV solar panels, the best places to install them, and the power levels.
When choosing a solar panel, there are some key terms to keep in mind:
- Monocrystalline, polycrystalline or amorphous
- rigid and flexible
- Fixed and Portable
Types of solar panels
Solar panels mainly include monocrystalline, polycrystalline and amorphous solar panels.
You may hear that one type of panel is more "efficient" than another, but that's just a difference in the size of the panels. Regardless of the technology, a 100W panel is 100W. That is to say, the conversion efficiency per unit area is high.
Monocrystalline panels take up the least amount of space, but are generally more expensive.
Polycrystalline panels are cheaper and have a larger size per watt. It has the same longevity and durability as monocrystalline panels.
Amorphous panels are very different from the other two panels. They are less efficient, heavier and more expensive than the first two panels. But these panels are best in cloudy weather and are not as severely affected by partial shading as other types of panels. And these panels are fairly durable even though they are flexible, so you can often see them sewn into backpacks and cloth.
We all know that the roof space of an RV is limited, so using a monocrystalline panel in an RV is the best choice because it has the smallest footprint.
What is a rigid solar panel
A solar panel with solar cells mounted under tempered glass is a rigid solar panel. They vary in size, and most panels are mounted in aluminum frames for easy outdoor installation. They are constructed to resist hail, sand and strong winds. The glass is scratch-resistant for long-term use.
Rigid solar panel features:
Wide range of sizes
Cheap per watt
Rugged, often with long warranties (over 10 years)
They are easier to position towards the sun due to their sturdy frame
Rigid solar panels are the best choice in terms of performance and durability.
What is a flexible solar panel
Flexible solar panels are flat panels covered with a protective layer of plastic. Since they don't have a frame, they have a small profile that allows for proper flexing, for example to accommodate the arc of the roof. And relatively lightweight. However, because the protective plastic on the surface is relatively soft, it is easy to scratch, and the impact is relatively small.
But bending the panel too much often leads to problems with internal connections and even short circuits between the cells. Because of these issues, flexible solar panels tend to have shorter warranties than rigid solar panels.
Also, flexible panels are not easy to adjust the lighting angle because their position depends on the surface they are attached to.
Flexible solar panel features:
- thin and light
- Can be bent up to 30 degrees
- easy to scratch
- short life
When using flexible panels, the more the panel bends, the less efficient it is. This is because the panel generates electricity best when it gets a consistent light throughout the panel. However, the light received by the flexible solar panel is inconsistent, some places are more, some places are less, so the power generation efficiency is low.
Flexible solar panels are only suitable where the surface has significant curvature. If it is a relatively flat surface, it is recommended to use a rigid solar panel.
Solar panel placement
If you're driving a large motorhome, the solar panels can be permanently attached to the roof. This is the easiest way. But in some cases you can also use a portable solar panel or solar suitcase to provide extra power or charge small electronic devices.
Fixed solar panels
Fixed solar panels are permanently mounted on top of the RV. You can add tilt mounts to manually adjust the angle and get the best power generation efficiency.
When installing solar panels, be aware that solar panels perform best at low temperatures. It's best to leave a little space between the panel and the roof to allow air to circulate to reduce the temperature of the panel. Mounting or gluing the panels directly to the roof loses bottom cooling airflow.
This is another reason why rigid boards have an advantage over flexible boards. Most rigid solar panels have some gaps within the frame. This prevents the solar panel from overheating and affecting the power generation efficiency.
Advantages of fixed panels:
- As soon as the sun comes out, they start collecting electricity.
- They don't take up valuable interior space.
- They are not easily stolen.
- Better suited for those who have high power consumption and need more than 200W of solar energy.
- Shade the vehicle to help reduce heat.
Disadvantages of fixed panels:
- They have a hard time getting the best sun exposure angle.
- Installation is a lot of work.
- Increase roof height, wind resistance.
- Fewer options for roof layout, less easy to install air conditioning.
- The vehicle must be parked in the sun to obtain electricity, which is paradoxical in the heat of summer.
Portable Solar Panel
Portable solar panels and solar suitcases are lightweight enough to carry in your car and take out while camping. These are great options if you're looking to charge your phone or laptop at the campsite.
Advantages of Portable Panels:
- Easier and cheaper for those who don't have the ability to do mods.
- Can be aimed at the sun for optimal exposure.
- Suitable for all kinds of vehicles (small cars, SUVs, etc.)
- Can also generate electricity when your vehicle is parked in the shade
Disadvantages of Portable Panels:
- Requires installation every time you are at camp
- Occupy space in the car, especially panels above 200W
- Can't charge while driving
- Not suitable for use in the city
How to make your solar panels more efficient
The biggest worry (and the biggest headache) when using solar panels to generate electricity is the weather. On cloudy or rainy days, your power generation is greatly reduced.
It is also important to clean the panels. Some dust or debris can also affect your power generation. Make sure to check your solar panels weekly for debris such as dust and leaves.
angle of the solar panel
A nominal 100W solar panel is measured by simulating sunlight with an instrument in an environment of 25 degrees Celsius, so when used in an actual outdoor environment, a 100W solar panel can only generate 70W~80W of power, which is still aimed at the sun. Light-time power generation, because the roof of the RV is flat, it is good to lose some power to reach 60W. If you can install a tilt bracket for the rigid solar panel, you can increase your solar power generation capacity by 20%.
Another great point about solar panels is that most solar panels are very sensitive to shade. Each little square on the panel is connected in some way, and if one of them is shaded, the entire row doesn't generate electricity. Therefore, if about 10% of the panel is covered, it is possible to reduce power generation by 90%.
So where the solar panels are installed is important, and these factors need to be considered when planning the roof layout. If your roof rack, exhaust fan, or storage box is blocking the panels, it can significantly reduce power generation.
How to Connect Solar Panels
Like batteries, solar panels can be wired in parallel or in series! What does it mean?
Parallel wiring is all about connecting the positive (+) poles of all panels and connecting all the negative (-) poles. This keeps the voltage constant but increases the current flowing into the controller.
Series wiring is simply connecting the positive (+) pole of one panel to the negative (-) pole of the other panel, which increases the voltage but keeps the current the same.