The 8 Best Solar Panels of 2021

DIY clean energy for homes, campers, and boats

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Our Top Picks
With a sturdy design and high-efficiency solar cells, these panels are versatile for use at home, off-grid, or on boats and RVs.
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The 110 watt polycrystalline panel kit balances affordability with efficiency,
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This polycrystalline solar panel is affordable while still offering a respectable 13.6 percent module conversion efficiency.
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This monocrystalline panel has an 18 percent efficiency rating and can be installed in a fixed location or used as a portable option.
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The folding design of this model keeps the solar panel surface protected from scratching or denting when you transport it.
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A shortcut solution for picking panels and a solar generator, this combination produces up to 1,920 watt hours of power.
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Raise your pool’s water temperature by 6 to 10 degrees when you mount this solar panel to your home’s roof.
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At just 0.15 inches thick and 2.53 pounds, this solar panel is lightweight and flexes up to 30 degrees for installation.
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Solar panels provide a way to capture the sun’s energy and put it to work as electricity. If you live want to power your whole home with the sun, your best bet is to work with a licensed solar installer. They can help design the best system for your property, pull the required permits, and take care of any roofing and electrical upgrades you may need. Depending on where you live, there may be some big tax incentives for getting rooftop solar.

However, there are also a number of off-the-self solar panels available for smaller-scale projects, like RVs, off-grid cabins, sheds, and detached garages. They can be a more affordable and attractive choice if you want to add electricity or lighting to a part of your home where it might be difficult to connect to the home's main electrical system. There are also portable panels that can serve as a back-up in case of an emergency power shut-off. Installing these units generally do not qualify for tax incentives.

There are three primary types of solar panels—monocrystalline, polycrystalline, and amorphous or thin-film panels. Each has its advantages and disadvantages when it comes to cost, efficiency, and ideal operating conditions and installation. If panels aren't connected to the grid, you'll also want a battery system to store energy for when the sun isn't shining.

We found the best solar panels for DIY projects, small off-grid applications, and for backup energy generation.

Best Overall: Renogy RNG-100D-SS 100W Monocrystalline Solar Panel

Renogy 100W Monocrystalline Solar Panel

Type: Monocrystalline | Dimensions:  42.4 x 20 x 1.38 inches | Wattage: 100 watts

What We Like
  • High efficiency rating

  • Lightweight

  • Compact

  • Designed to weather elements

What We Don't Like
  • No additional items included

For the most efficient solar panels on the market, start your search with monocrystalline panels. This type of solar panel can be more expensive but converts the sun's rays to solar energy with the highest efficiency rating, compared to polycrystalline or amorphous panels. In the case of these compact and lightweight solar panels by Renogy, you’ll see solar efficiency ratings of 18 to 21 percent according to the manufacturer. 

The Renogy 100 Watt Monocrystalline Solar Panel was designed to save space and weigh less, thanks to a lightweight aluminum frame. This makes these solar panels popular for RV installations, but they’re a good choice for roof installation and other applications as well. Specifically designed to weather the elements, these popular solar panels have been rated to withstand wind speeds up to 130 miles per hour and snow loads up to 125 pounds per square foot.  

This model has an IP65-rated junction box to protect against dust and rain, along with IP67 connector cables. Use the cables to connect this panel to an inverter, if you’ll be converting the energy to an AC current. You can also connect multiple Reonogy Monocrystalline panels together to create a larger array of solar panels for increased energy production.

Best Value: Nature Power 110W Polycrystalline Solar Panel with Inverter and Charge Controller

Nature Power 110W Polycrystalline Solar Panel with Inverter and Charge Controller

Type: Polycrystalline | Dimensions: 39.7 x 1.4 x 26.6 inches | Wattage: 110 watts

What We Like
  • Budget-friendly

  • Convenient

  • Can connect multiple Nature Value panels

What We Don't Like
  • Need to upgrade to add more panels

  • Needs an additional 12-Volt battery

If you want to combine convenience and value, consider this solar panel package from Nature Power. The solar panel bundle includes a 110 watt polycrystalline panel, along with an 11 amp charge controller, and 300 watt string inverter. You’ll need to supply a 12 volt battery to store captured the solar energy and complete the set-up.

You can connect multiple Nature Value solar panels for expanded energy output, but keep in mind that you’ll need to upgrade the controller if you choose to add more solar panels. The panel comes with a 25 year limited warranty, and the charge controller and power inverter come with a one year limited warranty.

Best Budget: WindyNation 100W Polycrystalline Solar Panel

WindyNation 100W Polycrystalline Solar Panel

Type: Polycrystalline | Dimensions: 40 x 26.4 x 1.2 inches | Wattage: 100 watts

What We Like
  • Affordable

  • Produces up to 100 watts

  • Durable

What We Don't Like
  • Less efficient than monocrystalline solar cells

  • Doesn't come with any additional components

If investment costs keep you from pursuing solar energy, polycrystalline solar panels are one option to lower the expense. This type of solar panel is less efficient than monocrystalline solar cells, but still provides a way to capture the sun’s rays and turn it into solar energy for your home

There are many options for budget solar panels, depending on the wattage and construction of the panel. The WindyNation 100 Watt Polycrystalline Solar Panel uses more affordable solar cell technology while still producing a panel capable of producing 100 watts (with the right sun exposure and additional installation components). While 30 watt and 50 watt panels exist—and cost even less, this affordable 100W solar panel is a better bet for many applications. 

Best Splurge: Goal Zero Boulder 100W Monocrystalline Solar Panel

Goal Zero Boulder 100W Monocrystalline Solar Panel

Type: Monocrystalline | Dimensions: 40 x 26.75 x 1.75 inches | Wattage: 100 watts

What We Like
  • 18 percent efficiency rating

  • High-quality monocrystalline solar cells

  • Integrated kickstand

  • Durable frame and reinforced corners

What We Don't Like
  • Expensive

Goal Zero makes go-anywhere solar panels that have a reputation for durability and longevity. Just be prepared to spend more than you might expect for this 100 watt panel. It costs about twice as much as a budget 100 watt solar panel, but offers a substantial 18 percent efficiency rating thanks to the high-quality monocrystalline solar cells. 

The Goal Zero Boulder 100W Solar Panel is built with a durable aluminum frame. It can be permanently installed, but it’s most often used as a travel option with a portable generator. The integrated kickstand provides angled support, though it’s worth noting that you can’t adjust the angle to optimize the amount of sunlight reaching the panel. It comes with a one year warranty.

Best Portable: Jackery SolarSaga Portable 100W Solar Panel

Jackery SolarSaga Portable 100W Solar Panel

Type: Portable and made with ETFE | Dimensions: 22.83 x 19.69 x 2.36 inches | Wattage: 100 watts

What We Like
  • Portable

  • Lightweight

  • Quick set up

What We Don't Like
  • Not waterproof

For solar power anywhere the sun shines, consider a portable panel. Commonly used for camping, outdoor events, or off-grid uses, a portable solar panel is quick to set-up and can give you the power you need. Use it to charge your devices, operate LED lights, or power a solar generator. 

The Jackery SolarSaga is a popular folding solar panel. This 100 watt model is lightweight and is made with ETFE, which is a fluorite-based plastic and is 100 percent permeable for UV rays. This translates into more light reaching the panel, resulting in an efficiency rating of 23 percent for the unit. Take note that this model is designed for short-term set-ups and temporary applications—it’s not waterproof, so you wouldn’t want to mount it outside or leave it exposed to rain or snow. Jackery also manufactures 60 watt and 200 watt versions of this solar panel.

Best with Solar Generator: Nature’s Generator 1920-Watt Hour Portable Solar Generator and Panels

 Nature’s Generator 1920-Watt Hour Portable Solar Generator and Panels

Type: Polycrystalline | Dimensions: 43 x 29 x 3 inches (panel), 22 x 19 x 19 inches (generator) | Wattage: 100 watts

What We Like
  • Single-step solution

  • Weather-resistant

  • Fuel-free generator

What We Don't Like
  • Expensive

  • Generator weights 266 pounds

Solar panels are often connected to a solar generator for an off-grid power supply solution. Deciding which panels you need to power a specific generator or power station, along with the necessary cables and inverter, can be a challenge. However, a solar panel and generator package—like this version from Nature’s Generator—is a single-step solution for solar power. 

The set-up includes a trio of 100 watt polycrystalline solar panels, along with a generator and power pod to store solar energy. You can install these weather-resistant panels on a roof or other outdoor setting without concerns about overexposure to rain or snow, while the fuel-free generator can be used inside without concerns about fumes. 

Making use of the included components, you can expect up to 1,920 watt hours of runtime when fully charged. To make it easy to put solar energy to work in your shed, cabin, or during a power outage, the generator features three 120-Volt AC outlets, a pair of USB ports, and a 12-Volt DC outlet. 

Best for Pools: Smart Pool S601 Pool Solar Heaters

Smart Pool S601 Pool Solar Heaters

Type: Passive heating | Dimensions: 240 x 54 x 2 inches | Wattage: Not applicable

What We Like
  • Cost-effective

  • Mounts to your roof to save space

What We Don't Like
  • Larger pools need more than one panel

Another popular use for solar energy is to warm up chilly pool water using the sun’s energy. Unlike photovoltaic panels that are used to generate electricity, this type of solar systems directly heats water by pumping the water through tubing. They are a passive means of heating your pool and can be a cost-effective alternative to conventional pool heaters. The Smart Pool S601 features a polypropylene tubing system that warms incoming pool water by passing it through an array measuring 4 x 20 feet. 

While some solar panels for pools take up square footage on the ground around your pool, this model mounts to your roof for out-of-the-way energy production. Every panel provides 80 square feet of surface area. Larger pools will require more than one solar panel for maximum heating results. 

Best Flexible: Topsolar Flexible 50W Solar Panel

Flexible 50W Solar Panel

Type: Monocrystalline | Dimensions: 20.47 x 25.59 x 0.1 inches | Wattage: 50 watts

What We Like
  • Offers more placement opportunities

  • Can flex up to 30 degrees

  • Available in 50 and 100 watts

What We Don't Like
  • Flexible panels tend to have lower efficiency

While many solar panels are designed with a sturdy frame for installation on rooftops or other flat surfaces, a flexible solar panel offers more placement possibilities. The Topsolar Flexible Solar Panel is available in 50 and 100 watt capacities and is capable of flexing up 30 degrees. 

Flexible solar panels are often useful for mounting on RVs, boats, or other concave surfaces. Usually they’re applied with adhesive or feature grommets that you can use with rope to secure the panel in place. Keep in mind that flexible solar panels are not the same as folding models; pay close attention to the manufacturer’s directions for max arc angle and installation requirements. 

Final Verdict

The Renogy 100W Monocrystalline Solar Panel (view at Amazon) delivers up to 100 watts of solar energy and can be installed for residential home use or on-the-go applications, like your RV or boat. With an energy efficiency rating of 21 percent, it’s the most efficient solar panel on our list. However, if you’re looking for a portable version for temporary installation or uses, then the Jackery SolarSaga (view at Amazon) is an affordable polycrystalline panel that sets up and folds up in a matter of moments. 

What to Look for in a Solar Panel

Type

There are three primary types of solar panels: monocrystalline, polycrystalline, and amorphous or thin-film. The differences between each relate to the type of solar cell technology used in the panel. Monocrystalline panels are generally the most expensive but also have the highest energy efficiency ratings. Polycrystalline solar technology is more affordable but also makes compromises in terms of energy efficiency, with lower overall conversion rates. Both monocrystalline and polycrystalline panels lose efficiency as temperatures rise.

Amorphous or thin cell solar panel technology has the lowest energy efficiency ratings and requires more surface area, but offers advantages in terms of flexibility and often affordability. These panels aren’t as ridged as polycrystalline or monocrystalline options and can be mounted on convex surfaces more easily. In addition, these panels often perform better in low light conditions and high temperature situations.

Energy Efficiency

The energy efficiency of a solar panel refers to how much of the sunlight received is converted into energy by the photovoltaic cells of the panel. The higher the percentage, the more efficient the solar panel will be. Top-quality monocrystalline solar panels often have energy efficiency ratings of 18 to 20 percent. Polycrystalline panels usually have slightly lower efficiency ratings of 13 to 15 percent. Amorphous or low-grade panels may fall as low as 7 percent.

Durability

Since solar panels are outdoor fixtures, durability is an important factor to consider. Many solar panels designed for fixed installation (like on a roof or permanently installed on an RV or boat) will have passed ASTM testing to evaluate their ability to withstand wind up to 130 miles per hour and snow loads up to 125 pounds per square foot. 

Most panels on the market are water-resistant, and also have sealed junction boxes to prevent damage from dust or moisture. However, some portable, folding solar panels are not weather-resistant. If you plan to install your panels or leave a portable solar outside—rain or shine, then it’s important to look for one that is water-resistant.  

FAQs 

How do solar panels work? 

According to the U.S. Office of Energy Efficiency and Renewable Energy, solar panels utilize photovoltaic cells to convert sunlight into energy. UV rays from the sun are absorbed by the photovoltaic cells and an electric charge is released. An internal electrical field creates a flow of energy that can then be used, converted, or stored in a battery.

Do solar panels require maintenance? 

There is very little preventative maintenance required for most solar panel set-ups. A visual inspection for broken panels or loose connections is a wise idea, but damage to the system will likely be first noticed by means of a drop in solar energy production.

You may choose to wash your solar panels of dirt, debris, bird droppings, etc. once a year. Keep in mind that only water should be used and you should avoid using high-pressure water, abrasive sponges, solvents, or hard water as these may cause damage to solar panels. 

Do shade and temperature affect solar panels?

As expected, solar panels require sun exposure to produce energy. Shade will negatively impact the efficiency rating of your solar panel, but it’s worth noting that amorphous panels have a reputation for better performance in shady conditions than crystalline panels. Most solar panels are able to generate some electricity even on cloudy or overcast days.

When you have an array of solar panels, a single shaded panel can shut down the flow of solar energy through the system depending on your setup. However, the type of inverter used with a solar panel can also overcome problems caused by shade. An MPP inverter, multi-string inverter, or microinverter can all maximize voltage output despite shady conditions on part of your solar array.

Temperature also affects solar panel performance. These panels absorb the sun’s rays, and with that comes a significant rise in the temperature of the solar cells. The temperature coefficient tells you how much efficiency the panel will lose in terms of voltage output for every degree above 77 degrees. 

Why Trust The Spruce?

This article was researched and written by Erica Puisis, a professional writer who specializes in large and small home appliances, along with home improvement features and additions.

This article was edited by Senior Editor Margaret Badore, who has been covering climate change and clean tech for over a decade. Her home is powered by rooftop solar.

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