The 9 Best Solar Panels For Off-Grid Systems

Editor's Notes

February 01, 2021:

The most noteworthy change made today was renaming the category. Noticing that some of our specialized solar-panel categories (eg: solar panels for boats, solar panels for RVs) were experiencing quite a lot of overlap, and also recognizing that the category’s former title – Best 300-Watt Solar Panels – is likely to start missing the mark as more affordable technologies continue to bring bigger panels to market, we wanted to create one consolidated category that represented the best the market has to offer for users interested in developing medium-sized arrays for off-grid applications.

With all that in mind, we focused Best Solar Panels For Off-Grid Systems on hardware that’s suitable for powering RVs, tiny houses, hunting cabins, house boats and so on. Note that we also made up our mind to worry less about including big panels (say 300-watt+), and focus more on including panels that present the best affordability on a cost-to-watt basis.

On top of renaming the category, it was also an extremely busy round of updates, as we bumped into a lot of availability issues along the way, likely as a result of companies discontinuing old panels in the wake of new offerings. In the end, the only previous selections we retained were the WindyNation 12V Kit and Renogy Monocrystalline Kit.

For users interested in building big arrays, we suggest you start with the Renogy 320-Watt, which is quite an affordable option, especially if you buy bulk (discounts are offered for packs of four, six and 30). For users looking to set up something temporary, we recommend the portable Dokio Flexible, which conveniently folds up and has a useful handle for transportation.

Many of these options are sold as kits, and come with all the necessary equipment, cables and mounting hardware, but that isn’t an absolute rule. So, be sure that the option you're considering comes with all that you need, and if it doesn’t, be sure to check out our rankings for solar charge controllers, solar power inverters, and even solar generators.

February 01, 2020:

Before considering which model is right for you, it’s important to understand a little about how photovoltaic systems work, assess how much power you need and identify the differences between the available options.

Renewable energy configurations suffer from intermittency. On clear days, when your rig gets 14 hours of uninterrupted sunlight it will produce more energy than on cloudy days with only 8 hours of interrupted rays. Therefore, your location will partially determine how much power your assembly will produce. When a 300 watt unit is at peak capacity, which means it is exposed to full sunshine, for one hour it will produce 0.3 kilowatts (or 300 watts) of electricity. To calculate wattage, multiply volts, the electricity’s force, by amperes (amps), the compound quantity of energy expended. So, 240 volts times 1.25 amps equals 300 watts.

Other important factors to consider are size and efficiency rating; the higher the efficiency rating, the less space you need to generate the same amount of power output. This is especially important if you want to maximize your power output on your rooftop or RV.

The majority of options offered today are either monocrystalline or polycrystalline technology, both of which are crafted from crystalline silicon. Monocrystalline technology has been around for longer and has a reputation of boasting the highest efficiency ratings, which can reach over 22 percent. These cells perform better in high heat setting and exhibit a solid color.

That said, polycrystalline is only marginally less efficient at turning sunlight into energy, is less expensive to produce and yields less manufacturing waste. Many of the models on today's market are polycrystalline. With lower efficiency ratings, polycrystalline cells tend to take up more space. They also showcase a speckled blue finish.

Both polycrystalline and monocrystalline cells are good quality. It’s more important to assess how much power you need and how long the warranty is.

Thin film amorphous technology is also available. While this technology is less expensive, has a flexible form and is less sensitive to changes in temperature, it is as much as four times less efficient. This means more space, cables and accessories to produce the same amount of energy. These models tend to deteriorate quicker and often include shorter warranties than the previously mentioned technologies.

With the exception of the Renogy Large Monocrystalline System, all of the choices on our list are off-grid packages. If you are going to install an off-grid system, you may find our list of Deep Cycle Batteries useful, as you will need battery storage, which is typically sold separately. On-grid configurations don’t require batteries. Instead your system would supply power to the grid, you would receive credits from your electricity provider and spend credits when you turn on the lights, power the refrigerator or run other appliances. It’s important to note that on-grid systems do not provide electricity when the power grid goes down.

As photovoltaic modules generate DC energy, you will also need an inverter to convert it to AC electricity. Since all of the options on this ranking except for the Eco-Worthy 240 Watt System do not include these devises, our list of power inverters may also be useful to you while setting up your system.

You'll also need require a charge controller to get your system up and running. This device connects the system to your batteries. Theses pieces are essential to ensuring your batteries receive the maximum charge they’re capable of and avoiding overcharging. Charge controllers also regulate battery voltage by reducing voltage when it gets too high.

There are two predominant types of charge controllers on the market, Pulse Width Modulation (PWM) and Maximum Power Point Tracking (MPPT). PWM models are commonly used in RV set-ups with 12 volt panels. MPPT models are more flexible in terms of the type of panels they can connect to. They are also up to 30 percent more efficient and more reliable in cold weather. MPPT controllers are larger and more expensive. While many of the packages on this page include a charge controller, here's our list of charge controllers to give you a sense of the best available options.