Choosing the right type of solar panel for van, bus, and RV life is essential if you’re making the leap into solar electricity. Purchasing solar panels for your skoolie, RV, or van is a great way to charge your batteries without having to be hooked up to electricity.
Once installed, they provide quiet, clean, and efficient energy whenever the sun is out. But, just because one solar panel works for one person, may not mean it’ll work for you.
With solar becoming more popular and the technology more advanced, it can become easy to get overwhelmed with what’s available on the market. So, how do you decide what type, brand, and size is right for you?
In this article, we’ll discuss the different types, styles, and sizes that may or may not work for you.
Still need more information about how to calculate your solar needs? Check out this article: DIY Solar System: How to Calculate Solar for Off-Grid Van Life
Photovoltaic Solar Technology Types
Most solar panels come in 3 types of cells including monocrystalline, polycrystalline (aka multi-crystalline), and thin-film. They vary in the materials they’re made of, appearance, performance, cost, and installation processes.
Solar panels are made from semiconducting material that converts light into electricity. The material most commonly used is silicone.
-Monocrystalline Solar Cells
Pros: High-efficiency & performance
Cons: High cost
This type of cell is made with the purest form of silicon. As a result, you’ll see a higher cost. With technology improving, you’ll start to see a smaller difference between mono and polycrystalline cells. The c-Si differs only about 10-22% in efficiency.
-Polycrystalline Solar Cells
Pros: Lower cost
Cons: Lower efficiency & performance
-Thin-Film Solar Cells
Pros: Aesthetic, portable, flexible, lightweight
Cons: Lowest efficiency & performance, low life expectancy
Thin-Film solar panels are made from a variety of materials including Cadmium Telluride, Amorphous Silicon, or Copper Indium Gallium Selenide. Using different materials causes different voltage outputs, power outputs, temperature sensitivity, and expected life. Since this is also a newer technology, there is a significant difference in efficiency from crystalline to thin-film solar cells.
According to Joseph P. O’Connor from Off Grid Solar: A Handbook for Photovoltaics with Lead-Acid or Lithium-Ion Batteries, this panel is not recommended for an off-grid setup unless you are familiar with the product or willing to experiment with the advantages and disadvantages of the technology.
We’d recommend looking into mono or polycrystalline solar panels to meet your energy needs.
Types of Solar Panels: What Are the Options?
Rigid panels contain solar cells that are mounted underneath tempered glass. You can purchase residential house panels all the way to 50w device chargers. The tempered glass designs help to protect the cells from hail, sand, and wind. In addition, they’re scratch-resistant. They’re a great option for long-term use. As an added perk, most panels that you buy new come with 10-25-year warranties.
Pros: Rigid panels are easy to clean in winter, cheaper per watt, easier to position toward the sun, and come in a wide range of sizes.
Cons: It can be difficult to get optimal solar without incorporating a tilt into your install. To tackle this challenge on our build, we built a linear actuator system on the left side of our solar rack. This allows for optimal solar collection, especially during the winter when there’s less sun.
We’d recommend this type to anyone looking into solar. They are durable, cheaper per watt, and perform efficiently.
Flexible Panels contain flat cells that are molded with a layer of protective plastic on top. They are capable of bending up to 30 degrees, which makes them a bit less noticeable than rigid panels. However, they are more prone to scratches.
Pros: They are light and low profile, making them a perfect option for van lifers looking to stealth camp. They are also easier to install and require few holes or construction to your roof.
Cons: The more you bend flexible panels, the less efficient they are since there’s less direct sunlight. The lifespan is also much less in comparison to rigid panels.
These are a great solution for someone with a van or other low profile rig looking to stealth camp. They’re always a fair option for someone that is not interested in drilling holes in their roof or doing other construction like building a roof rack.
Fixed Panels are permanently or semi-permanently mounted to a vehicle or home. They can also be upgraded with tilt mounts for optimal solar collection. Most rigid panels already come with a bit of clearance built within its frame. It’s important to remember that solar panels perform best when kept cool. When designing our solar rack, we intentionally designed a gap between the bus’s roof and panels. This helps allow important airflow underneath the panels while also keeping the panels from overheating the bus.
Portable Panels can come in suitcases or mobile forms that can be set up after you park. These are great choices for either a weekend warrior or minimalist just looking to quickly charge a phone or laptop at a campsite. It’s a much cheaper option and more suitable for smaller rigs.
Solar Panel Efficiency: How Can I Improve It?
The Effects of Temperature on Solar Panels for Van Life
If a solar module’s cell temperature rises above 25°C, the system’s power output will decrease below its optimal performance. The heat adds resistance to the flow of electrons. The performance drops by about 0.5% for every degree above 25°C.
That’s why it’s so important to consider factoring in a gap between your solar panels and the roof of your rig. This will allow for proper ventilation that will cool your panels and your roof.
In comparison, winter weather can also cause issues for your panels. On bright winter days, it’s possible to outperform the STC power output due to reduced internal resistance. Due to the power increase, it’s important to ensure that the string of modules will not exceed the voltage limits for the rest of the system. High voltage can blow fuses or circuit breakers, as well as harm electronics.
The Effects of Shade on Solar Panels for Van Life
Unfortunately, even a small amount of shading on solar modules can significantly reduce the production of energy. Even with 10% shading, the production of an entire system can be decreased by 50%. In addition, if a solar module does not bypass diodes, power loss could reach 75%.
Most solar panels for van life include cells that are connected in a series. As a result, generated electricity needs to travel from one cell through all the other cells before exiting the panel. If a cell on that downstream is shaded, the voltage will drop due to increases in resistance. Eventually, all the cells in the rest of the series will have less power.
We’d recommend looking into solar modules that have bypass diodes. They help redirect the flow of electricity when portions of your solar cells are in the shade. Located inside of a module’s junction box, bypass diodes work alongside photovoltaic cells (PV) to redirect currents in the event of shade.
Opening the junction box can void a module’s warranty. Make sure to check the owner’s manual before doing so.
Series vs. Parallel Solar Connection Methods
When connecting multiple solar panels, you have two options: Connect them in a series or in parallel.
A series connection has double the voltage while the current remains the same. Parallel connections have double the current but the same voltage. Strings of solar modules can range from 2 to over 20 depending on your energy requirements.
Similar to connecting batteries in a series, you can plug a positive lead of solar module into a negative lead of another. This adds to the voltage while maintaining a consistent current. In order to maintain high efficiencies, it’s recommended that you use the same type of solar module in every string (modules that are connected). If you do connect modules that are not the same together in a series, the string is reduced to the module with the lowest amperage.
Essentially, you can string together as many solar modules as required until the desired voltage is reached.
Parallel connections of solar modules require a specific connection device including outdoor combiner boxes or outdoor rated Y-combiners. These boxes help terminate conductors. Series connections, on the other hand, use male-to-female connections which eliminates the need for a connection terminal.
All of our positive leads are together and all of our negative leads are together which is parallel (same voltage, but double charging amp – so charges faster). If the solar panels were 12v, we would have to pair them together in a series of solar panels to output a higher voltage than the battery.
Most Recommended Solar Panels for Van Life
Multi-layered sheet laminations enhance cell performance and ensure long service life. 100W-200W
Positive output tolerance (0-3%); withstands high winds (2400Pa) and snow loads. 100W
Monocrystalline panels come with high-efficiency cells that help increase module efficiency. 100W-200W
Two 100 Watt solar panel provides up to 200 watts of clean, free, renewable power.
Pre-drilled holes on the back of the panel for fast mounting and securing.
Corrosion-resistant aluminum frame for extended outdoor use, allowing the panels to last for decades.
Thanks to advanced polymer materials, this product weighs 70% less than conventional solar panels for van life, making transportation and installation a breeze. 50W-175W
The SunPower cell is made for up to 23.5% efficiency, while most monocrystalline panels in the market are 17%-19%.
ETEF panel weight approximately 20% of a glass framed one. Size:45.3*21.1*0.15 inch, net weight:3.97 lbs. 100W-800W
Adjustable, Corrosion-Resistant aluminum stand as well as a heavy-duty handle and latches for longevity. 100W-200W
Bypass diodes minimize power drop caused by shade and ensure excellent performance in low-light environments.
2 pieces of foldable 50W high-efficiency Grade A monocrystalline solar panels for van life with 10A charge controller, can work as a battery ready kit or a generator ready kit or BOTH.
Solar Panel Kits for RVs
200 Watt solar charging kit provides up to 200 watts of clean, free, renewable power.
Negative Grounding controller with battery reversed, overloading, short-circuit, and overcharging/discharging protection ensures the broader off-grid applications and safety.
PWM Solar Charge Controller has user adjustable settings! LCD Screen shows system amperage, voltage, amp-hours, temperature, and DC load draw.
Monocrystalline solar cell efficiency: 21%；Ideal output: 2000Wh per day; can fully charge a 200Ah battery from 50% in 3 hours (depending on the availability of sunlight).