Having a source of electrical power when you are off the grid can really elevate your backcountry game. A portable solar system can provide electricity for your adventures for extended periods of time by collecting, storing, and using solar-generated energy. This can allow you to power and recharge cameras, computers, lights, heaters, and small electronic appliances, including small heaters and portable refrigerators.
In recent times, a whole industry has emerged to take the pain out of building an overland solar system. Companies like Goal Zero, Jackery, Rockpals, and Suaoki produce relatively turn-key solutions for storing and using solar energy off the grid. For many people, these are replacing other options, such as dual battery systems, DIY solar systems, and gas-powered-generators, which we’ll discuss below.
Here, we will cover the basics of these two-part portable solar systems, which combine solar panels with a power station for storing and distributing the electricity generated by the panels. At the end of the article is information about alternatives to these systems, which might be options depending on your needs.
It’s worth noting that you don’t absolutely need a power station to use solar panels. Many of the newer portable panels now have USB plugs so you can plug electronic devices directly into them. However, if you are planning to spend any serious amount of time off the grid, having a power station for longer-term storage can be a real game-changer.
If you are just looking for a quick recommendation, here is a versatile, quality option from Jackery for a overland solar system that will fit most people’s needs (through charging in your vehicle and/or the panel, you could run a small overlanding fridge on long trips):
Jackery Explorer 500 Portable Power Station
Jackery SolarSaga 60W Solar Panel
Overview of Portable Solar Systems
As mentioned above, a portable solar system has two parts: the panel(s) and the power station.
The panels, also known as photovoltaic panels, capture energy from sunlight and convert it into electricity. Portable solar panels have gotten much more efficient, lighter, and easier to store and carry in recent times. Newer panels also come with outputs for USBs and other types of power cords that allow you to plug electronics directly into a panel.
The power output of solar panels is rated according to the amount of direct current (DC) energy it generates per hour, measured in watts, under optimal conditions. A popular size of portable solar panel used for RVing and overlanding generates 100-watts. In a sunny place like Southern California, a 100-watt panel might produce 450 watt-hours of power on average, while it might only produce 280 watt-hours per day in a cloudier local such as the U.S. Midwest.
If you aren’t going to use all of the energy during the day, why not store the power for later? That’s where the power stations come in. Portable solar power stations center around a rechargeable lithium-ion battery that is used to store and then distribute the energy collected by the solar panel. These can also typically be charged by plugging them into a home wall socket or by your vehicle’s electrical system. You can charge the power station before your trip, then recharge it while you’re driving or using your solar panel when you’re in camp.
Beyond the battery, turnkey solar power stations incorporate two devices: a solar charge controller and an inverter. The controller (also known as a regulator) manages the voltage and/or current to keep the battery from overcharging. The inverter converts the direct current (DC) coming out of the solar cell into alternating current (AC), which is the kind that comes out of your wall sockets at home. This allows you to use electrical devices designed for AC power. We recommend you look for power stations that produce “pure sine wave” AC, as this form of current is what most AC power devices are designed to operate with.
The most important characteristic of solar power stations is their storage capacity, which is rated in watt-hours. A 500 watt-hour power station can deliver somewhere in the range of 500 watt-hours of energy on a single charge. We’ll get into more about what you might be able to power with that amount of energy below. But to give you a sense, a fully charged 500-watt power station could power a 60-watt portable refrigerator for around 35 hours on a single charge.
Often, manufacturers will also provide the charging times for power stations, which varies depending on whether you are charging it from a home wall plug, your car’s electrical system or a solar panel. It may be stating the obvious, but larger capacity batteries take longer to charge than smaller ones.
How to choose an overland solar system
The good news is that nowadays you have a lot of options for turnkey portable solar power systems. The bad news is that figuring out which one is right for your adventures can still be challenging. We’ll try to arm you with the info you need to sort it all out.
How will you use the solar system?
The first step is to consider how you plan to use the system. If you are only using your system to charge your phones, cameras, and laptops, or for powering some LED lights, you can go with a smaller (less size and electrical production and storage).
If you are planning to use your power station to run larger electronics, such as a portable refrigerator, a common element of overland kitchens, or you’ll need a larger power station than if you only plan to use it to power electronic devices that draw less energy.
Chart below will give you idea of roughly how long you might expect fully charged devices of various capacities to power different devices.
To determine how long your solar station could power a larger device, like an overlanding fridge, multiply the capacity of your power station by 0.85 and then divide that by the power required by your device.
Power station capacity x 0.85/Device power requirement
The 0.85 multiplier reflects the fact that no system is completely efficient and some power will be lost as energy is transferred through the system to your devices.
Oftentimes, the manufacture of a device may give energy usage in amps and not watts. To convert amps to watts, so you are comparing apples to apples (watts to watts), the formula is watts = amps x volts. So for a 12-volt device that draws 10 amps per hour, you get watts = 12 x 10, which gives you an energy usage of 120 watts per hour.
Let’s say you have a portable refrigerator such as a Dometic, ARB, or Engel fridge, that requires 12 watts of electricity per day (the actual power draw will depend on your temperature settings, outside temperature, and other factors). Using the equation above, a 500 watt-hour power station could power the fridge for around 35 hours on a single charge. Of course, if you have opportunities to recharge the power station with your vehicle or solar panel, you can run devices for longer, which is something we’ll get into in the next section.
How long will you use and recharge the system?
Once you know what you plan to power, you’ll need to consider how long and how often you’ll be using your solar power system. If you will only use it for weekend camping trips, you could most likely go with a lower capacity system than if you are prepping for a months-long overland trip.
Also, consider what opportunities will you have to recharge the power station. If you will be driving frequently for long distances during your trip, you can recharge your power station from your vehicle. If you plan to set up camp for long periods of time, you can use your solar panel to charge the power station while in camp. On the other hand, when traveling in an area where it’s cloudy and raining or snowing a lot, your opportunities to recharge with solar panels may be limited.
The manufacturer of your power station will provide information on how long it takes a unit to recharge, which will likely vary depending on whether you are plugged into an outlet in your house, your car, or using your solar panel. For instance, a 500 watt-hour power station might take 7-8 hours to fully charge when plugged into a wall outlet and 8-9 hours when plugged into a solar panel.
One thing to consider is that you can use your power station to power devices while you are charging it with a solar panel during the day. So you would only need to use the power station alone to power devices overnight when the sun is down.
Every situation is different but, generally speaking, if you plan to use less power, take shorter trips, or have frequent opportunities to recharge, a smaller system will suffice. If you will use more power, are going on longer trips, and/or have fewer opportunities to recharge, a larger system might be warranted.
If you want to make sure you have enough power for your needs and have the cargo capacity, err on the side of purchasing a larger system. A larger capacity system can capture energy from the sun more quickly, has greater storage capacity, can power a wider range of devices, and will require recharging less frequently. This could be very appealing to people with heavier energy requirements and/or on longer trips. The trade-off is the higher cost of the system, greater weight, and the cargo space it takes up.
What panels and power stations work together?
You’ll want to make sure when buying solar panels and a power station that they are compatible. Many of the companies that make portable solar panels also make power stations and an easy way to make sure of compatibility is to look at their pairing recommendations. These are typically easy to find on their websites and promotional materials — they want you to buy both from them, after all.
That said, most portable 12v panels marketed for outdoor adventures will work with any of the popular power stations, regardless of what brand they are. Two popular sizes of solar panels for overlanding are 100w and 60w options, as these will charge power stations in a reasonable amount of time and directly power a range of devices. If it turns out that you need more power down the road, you can always purchase another panel and daisy chain them together.
Alternatives to Portable Solar Systems
It’s important to note that these turn-key portable solar systems aren’t the only option. In fact, people have been building overland power systems for a long time, and these other setups still may be the best option for certain use cases.
If you go to any campground that allows RVs but doesn’t have electrical hookups, you encounter people using gas power generators. Typically, the generator is being used to recharge a battery system in the RV so it can power the various electrical devices throughout the night and day. Gas-powered generators offer the advantage of being able to generate electricity when the sun doesn’t shine — at night or in cloudy conditions. The downsides are many – you need to bring fuel for the generator, which is cumbersome. Generators themselves tend to be bulky and heavy. And they are loud, which detracts greatly from the backcountry experience.
Because of the many downsides of gas generators, prior to the availability of small, efficient solar panels, many overlanding enthusiasts used dual-battery systems to leverage the power of their vehicle’s engine to generate and store electricity.
In this setup, a second automobile battery is added so that it charges as the vehicle’s engine runs. You can then draw on that battery to power electronics, without the risk of draining the primary vehicle battery. Dual battery setups are very space-efficient, as all that’s really needed is the battery and some wiring.
One major downside is that they can only charge when the vehicle is running. Installing one is not a trivial task and requires complex wiring harnesses. Systems that are hard-wired into the vehicle can’t be loaned out or carried away from the vehicle, which limits their versatility.
Lastly, some overlanding enthusiasts build custom solar systems for their rigs, purchasing and configuring the solar panels, batteries, wiring, and controllers themselves. The advantages of this approach are the opportunity to build a system to very specific standards, upgrade and replace components as they age or technology advances, and potentially cost savings.
The primary downsides are the time suck of researching and the potential for error in building the system. The internet is a great resource, but it can be bewildering to sift through the enormous amount of information online nowadays about how to build solar systems for overland rigs and RVs – not to mention the MANY strong opinions.
If you are curious about how to build a DYI portable solar system, this video is worth a watch: