5 Portable solar panels with USB ports
If you frequently find yourself away from a power outlet, these little portable solar panels can keep your electronics powered indefinitely.
Does your life involve taking lots of little electronic devices with you? Do you constantly worry about how much battery charge you have? Is the nearest outlet sometimes too far away?
The solution that people typically reach for is an external battery. These are great and cheap, but suffer from a couple major flaws. First of all: you need to remember to keep them charged. If you have difficulty remembering to charge your phone, with an external battery now you have two things to keep track of.
A second big flaw is limited battery life. A cheap battery might recharge your phone once or twice, but what if you’re away from an outlet for longer than that?
That’s where these small portable solar panels can save the day. With one of these, you can keep your devices powered indefinitely. All you need is sunlight.
Which one is best for you depends on how much electricity you need. We’ve published articles on other types of portable solar panels, including flexible solar panels you can velcro to the roof of an RV and foldable solar panels that you can pack in the trunk of your car.
None of those are good choices if you need something really compact. Instead, the devices listed here are about the size of magazine and can comfortably be carried in your bag or backpack. While they only supply up to a few dozen watts, that’s enough to recharge your phone, tablet, or even some smaller laptops. And unlike an external battery, you never have to remember to charge them.
What’s a small portable solar panel good for?
The most obvious use for one of these products is to keep your electronics charged when you’re off-the-grid, like on an extended camping trip. But these panels can be handy even when you’re not roughing it.
There are many times when you might need a charge but can’t get near a power outlet. Do you ever struggle to find a power outlet in an airport or coffee shop? If you’re near a sunny window, just plop down your solar panel and you can keep your phone topped up.
Same thing in an office. Small laptops often don’t have enough USB ports for all your accessories. If can’t find a spare port to charge your phone, if you have a sunny desk one of these panels could supply enough power to keep your phone going all day.
What’s a small portable NOT solar panel good for?
Don’t buy one of these solar panels to save the environment. Rooftop solar panels that sit in the sun all day, every day, and will pay back their embodied energy in somewhere between one to four years.
Embodied energy is the amount of energy required to manufacture and deliver a product to you. After a few years, rooftop solar will have generated more electricity than its embodied energy, after which the panels will be energy positive and offset fossil fuel generation up until their expected lifespan of 25 years or even more.
Not so with these little panels. There’s a couple reasons why. First, these panels won’t get the same amount of usage as rooftop solar: you aren’t going to use them to generate power from sunrise to sunset. Secondly, their expected lifespan might be only a few years. They simply aren’t designed to be as robust as a rooftop panel, which is engineered to withstand hail and windstorms and keep on ticking for 25 years.
There are some products in this category that pitch themselves as environmental products, perhaps most notably the Grouphug Window Solar charger which got $150,000 of investment from Mark Cuban on the TV show Shark Tank. Even though the Grouphug company promises to use carbon offsets to address the embodied energy footprint of its products, that still doesn’t address the fact that there are far better ways to spend your money to save the environment - especially at the steep price of $149 that Grouphug charges for a measly 10 watt panel.
In contrast, the 10 watt Renogy panel below costs only $20. There’s nothing really wrong with what Grouphug is selling as long as you think of it as a fashion item. But if you want to save the environment, save your $149 and spend it on window caulk or a smart thermostat instead.
What to look for in a portable solar panel
There’s a few reasons why the solar panels listed here selected as the best choices. Whether you go with one of them or shop around on your own, here are some features to keep in mind.
Bigger panels generate more power
The bigger a solar panel is, the more light it can collect and turn into electricity. That’s obviously a tradeoff when you want a product that’s small, but the panels in this article all get around that problem with a folding design.
When packed away, these solar panels are no larger than a magazine or thicker than a paperback book, but unfold to reveal mutiple solar panels that can generate up to 40 watts of power in the case of the largest device listed here.
How much power do you need?
Portability is a nice feature, but remember that the power rating of these panels is under ideal conditions: bright sunlight with your panel angled to catch the maximum rays. This means that you don’t mind a little extra bulk, it’s a good idea to buy a panel that’s a little larger than you think you’ll need.
Those little cube-sized chargers that come with your smartphone are usually 5 watts. The smallest panel in this article can generate 10 watts in full sun, which should be enough to charge your phone at the standard speed (not a quick charge).
USB output power
All of these solar panels include one or more USB-A ports, which are the ubiquitous rectangular ports that you see everywhere. Even if you have a newer device with a USB-C charging cable, you can get a USB-A to USB-C adapter that will supply power to it.
However, not all USB outlets are the same. We compared products with the same rated solar power output, but found different ratings for the USB power output. For example, on Amazon we found a 20 watt panel with USB ports rated for only 2 amps. Meanwhile, the Ryno Tuff product below is a 21 watt panel with 2.4 amp USB outputs.
Renogy E.FLEX10 10 watt solar panel
- 10 watt monocrystalline solar
- One USB-A port with 1.92A output
- Folded dimensions: 9.5 x 5.9 x 0.26 in
- 1 year warranty
Renogy is a California-based company that generally makes high quality gear, and this folding panel is nearly the smallest wattage solar panel they sell. They also offer a 5 watt panel called the E.FLEX5, but because the E.FLEX10 has about the same dimensions when folded, you're better off spending a couple bucks more to get twice the solar generation.
10 watts of solar should be enough power to keep the 1.92A USB port fully supplied with power even in slightly less than ideal sun, but be aware that 1.92 amps will only slow charge a smartphone. Depending on your needs, that still might be okay: you could pair this panel with a small external battery. A sunny day should supply enough power to keep the battery topped up.
Perhaps the best feature of this little solar panel is the price: it's currently on sale for only $20.
Price: about $20 Check pricing on Amazon
Anker 15 watt solar panel
- 15 watt monocrystalline solar
- Two USB-A ports with 2.1A output with fast charging
- Folded dimensions: 11 × 6.3 in
- 18 month warranty
Anker makes very high quality gear, and that's reflected in the slight price premium for this 15 watt panel compared to the Luminiser panel below.
This device unfolds to reveal two high efficiency solar panels and a pocket in which you can tuck your phone to keep it shaded while charging in the sun. The USB ports deliver up to 2.1 amps of power and include Anker's PowerIQ fast charging software. With 15 watts of solar cells, this device should have enough power generation to charge a phone even if it's a little hazy outside.
Price: about $50 Check pricing on Amazon
Luminiser 15 watt solar panel
- 15 watt monocrystalline solar
- Two USB-A ports with 2.4A output
- Digital ammeter display
- IPX4 waterproof rating
- Folded dimensions: 11.4 × 6.5 * 1 in
- 1 year warranty
- Also available in 21W and 28W sizes
This folding solar panel is very similar in design to the Anker product above. It has a couple additional features, such as a digital ammeter that shows you how much the panel is generating, and slightly more powerful USB ports. It's also $10 cheaper.
However, the Luminiser brand doesn't have Anker's reputation for high quality, and it comes with a shorter warranty. The Anker product also has a slightly higher rating on Amazon. Whether that's worth the small difference in price is something for you to decide.
Price: about $40 Check pricing on Amazon
Topsolar 30 watt solar panel
- 30 watt monocrystalline solar, 4 panel design
- One USB-A port and one USB-C port with 2A output and quick charging
- One 15V DC port
- Comes with alligator clips and a cigarette plug adapter
- Folded dimensions: 11 x 6.1 in
- 1 year warranty
When this product is opened up, you get 4 solar panels to generate up to 30 watts of power. That's getting to the point where you can charge larger devices such as tablets and small laptops. The USB-C port supports power delivery (PD) for faster charging. It also comes with a 12v DC output, which can let you charge some Windows laptops directly. It also includes alligator clips and a cigarette lighter apapter, which means you could use this panel to trickle charge a car battery or use it to power many 12v devices.
Price: about $75 Check pricing on Amazon
KINGSOLAR 40 watt solar panel
- 40 watt monocrystalline solar, 6 panel design
- One USB-A port with 2.1A output
- One 18V DC port with 2.2A output
- Comes with alligator clips and round DC adapters
- Folded dimensions: 13 x 7.1 x 2.3 in
- 1 year warranty
This 6-panel solar array will provide up to 40 watts of power, which is enough to charge a smaller laptop in full sun. It has a single USB-A port with a 2.1 amp rating. The 18V DC port gives you the ability to supply power to a laptop or charge a larger external battery.
Weighing in at 2.2 pounds, this is heavy enough that you might think twice about carrying it with you every day. However, if you need quite a lot of power generation, this KINGSOLAR panel could do the trick. It's also a pretty good deal at this price.
Price: about $63 Check pricing on Amazon