Can a 15 Watt solar panel actually power anything, or is just a toy that will ultimately let you down? This is the eternal question of a person considering a smaller solar panel.
Before we pass judgment on whether small solar panels are worthy of our hard earned dollars, let’s consider where the 15 Watt solar module fits in the solar panel size spectrum. Is it really so small after all?
To figure this out, we need to take a look at some of the solar module sizes that are available.
15 Watt Panels Vs. Other Solar Panel Sizes
Coleman offers a 1-watt portable solar panel that is used for maintaining small batteries. A 15 watt panel offers fifteen times more power than one of these maintainer panels. It also offers over seven times the wattage of the 2 watt solar panel offered by Voltaic Systems. With this in mind, we can safely say that a 15 watt panel is far from the smallest solar panel available.
But what about the big boys? Phono Solar, Canadian Solar, and other companies offer panels at the 450 watt level. This is 30 times the power of a 15 watt panel! Considering this, I think it’s safe to say that a 15 Watt does not belong in the ‘large’ category of solar modules.
If a 1 or 2 watt panel is extra small and a 450 watt panel is extra large, a medium sized panel would be somewhere in the 85 – 150 watt range. This confirms that a 15 Watt solar panel does indeed belong in the ‘small’ category. Let’s just say it is in the middle section of the small solar panel category.
Now what kind of power can we expect from this ‘middle of the small category’ kind of solar panel?
What Will A 15 Watt Solar Panel Run?
Although you wouldn’t want to attempt to power your entire house with a 15 watt panel, there is a surprising number of things that can be powered, charged, or maintained by a panel of this size. Here are some of the things this panel can do:
- Charge a Car Battery
- One of the most common applications for these panels is charging a 12 volt battery. The most common 12 volt batteries are the ones you find in cars and trucks (not Teslas and other electric vehicles, but the old fashioned gas-powered ones). A 15 watt panel is a good size for keeping these batteries topped up if your vehicle will be sitting for a while. Make sure the panel has a built-in charge controller to ensure your battery doesn’t get overcharged.
- Charge an RV, Motorcycle, Marine, or ATV Battery
- A 15 watt solar panel can charge and maintain the batteries in a variety of recreational vehicles. To keep your battery healthy, just make sure your panel has a charge controller or that you add one to your setup.
- Charge Your Gadgets
- Have you ever wished you could keep your cell phone, tablet, or laptop computer topped up during a camping trip or power outage? A 15 watt panel could be just the thing you need. Some panels have a built-in usb input so you can charge directly and others will require additional hardware.
- Off-Grid Applications
- If you need power far away from the grid, a 15 watt panel can be very helpful. These applications include powering up a deer feeder or an electric fence.
Now you’re probably wondering how quickly a 15 watt panel will charge your batteries and devices. This depends on many factors, including:
- Sunlight intensity
- Efficiency of solar panel
- Battery age and type
- Charge controller
To get a rough idea of how long a solar panel will take to charge you batteries and gadgets, we need to do a little math (don’t worry, we’ll keep it simple).
The first thing we need to figure out is how much electric current the 15 watt panel will produce. To get this number we simply divide the power in watts by the voltage in volts. This tells us that a 15 watt solar panel will provide about 1 amp of current in full sunlight.
Then we need to determine the number of ‘amp hours’ (Ah) that are in our battery or device. For instance, an iPhone 13 Pro has a battery capacity of about 3 amp hours.
Now we just divide the amp hours in the battery by the amps our solar panel produces:
3 amp hours = 3 hours
1 amp
So, without taking into account all of the factors we mentioned above, it will take about 3 hours to fully charge your iPhone with a 15 watt solar panel. You can use this calculation to get an approximate charging time for other gadgets and power banks.
If you’re just using your solar panel to maintain your car, motorcycle, or marine battery you won’t need to calculate charging time. Your panel will just be keeping your battery at its optimum state and saving you from the inconvenience of a dead battery. If you’re planning on using your panel for car battery charging you might want to look for one that comes as part of a kit that includes a 12V car adapter, a length of wire, and battery clamps.
Types of 15 Watt Solar Panels
Once you’ve confirmed that a 15 watt panel will suit your needs, you have a couple of questions to consider:
- Amorphous Panel vs Monocrystalline or Polycrystalline Panel
- Monocrystalline solar panels are considered the ‘top of the line’ option and offer the highest solar panel efficiency available. Polycrystalline solar panels are less efficient but can also be less expensive. Amorphous solar panels are created using a ‘thin-film’ technology that is lightweight and usually less efficient in optimal conditions. In addition to being lightweight, however, amorphous solar technology operates effectively in all daylight conditions (even on cloudy days). This can make it a great option for portable applications.
- Rigid vs Folding or Roll-Up Solar Panel
- A rigid solar panel is durable and can be secured to many flat surfaces in a very secure way. Folding solar panels are more lightweight and are much easier to throw in a backpack when you’re on the move. A roll-up solar panel can also be quite convenient to carry and is another lightweight option for portable solar applications.
How Much Does a 15 Watt Solar Panel Cost?
The good news is that the cost of solar panels has come down dramatically over the last decade. With that being said, there is still quite a range of prices when you’re doing your solar panel shopping.
Nevertheless, the following options should give you a good starting point (of course, all of these prices are subject to change):
- The SunJack 15 Watt Foldable Solar Panel can currently be found for $59.95. This is a great portable option to keep your gadgets fully charged and it includes USB-A and USB-C connectivity. This option also includes a built-in smart chip that identifies your device and provides the optimal charging speed. Charging will also automatically restore if shading occurs.
- The FlexSolar 15 Watt Portable Solar Panel Charger is currently $49.99. This is another great foldable portable option to keep your gadgets charged. This panel also features a USB-A port, a smart chip, and automatic restart feature.
- The ACOPOWER 15 Watt Polycrystalline Panel is available for $34.90. This is a rigid panel and isn’t as portable as a foldable solar panel. It could be a great option for a stationary application like charging a security light. This panel does not include a charge controller or battery.
- The Nature Power 15W Semi Flexible Solar Panel is a more pricey option at $109.76. On the bright side, this panel is very light weight and can mold to a curved surface. It is also made from high efficiency monocrystalline solar cells. Could be a great trickle charger option.
As you can see there is quite a range of prices but there are some great deals to be had. Now hopefully you’re ready to start shopping for a 15 watt solar panel of your very own. If you think you might need a larger solar panel, check out the following pages:
Good luck!