Updated 1 month ago

A complete review of Grape Solar panels

Written by Ana Almerini

A complete review of Grape Solar panels

Find out what solar panels cost in your area

Grape Solar is a Eugene, Oregon-based solar panel manufacturer offering a new brand of solar power solutions, DIY installation kits, and portable solar panels. 

While Grape Solar has only been in the building applied photovoltaics (BAPV) market since 2009, the company has established a solid reputation for producing affordable, durable solar panel kits in the United States. 

The company offers both polycrystalline and monocrystalline solar panels and installation services through its professional network of contractors. Grape Solar also sells kits directly to the public through major retailers like Costco, Amazon, and Home Depot.

In this blog, we will take a look at Grape Solar and review their solar energy solutions. We’ll also break down what makes this company different and where you can buy Grape Solar panels and kits.

Key takeaways

  • Grape Solar panels are a great DIY option for your home or RV that you can buy directly from Home Depot or Costco.

  • Grape Solar offers affordable solar panel kits but there are better warranty options on more many other solar panel brands.

  • Installing Grape Solar panels on a home without the help of a solar professional might end up costing you more money.

  • Compared to other solar panel brands, Grape Solar loses more efficiency, or ability to produce energy, with higher temperatures.

  • To connect to the grid, you will be legally required to go through a licensed contractor.

What makes Grape Solar panels different?

Grape Solar panels are unique in that consumers can buy them directly from retailers like Home Depot and Costco, unlike traditional solar panel manufacturers. Instead, those companies sell their products through third-party distributors and installers. 

The kits themselves are similar to others on the market, such as Renogy Solar. However, Grape Solar’s kits aren’t limited to RVs and trailers - they can retrofit your entire house, as well. Most of the competition only sells small-scale, typically 100 watt solar kits for off-grid, nomadic lifestyles. 

Grape Solar offers DIY kit options that include solar panels, solar inverters, and racking systems. Most kits include the solar panels, a charge controller, extension cables, and a manual, as well.  

Read the latest Grape Solar reviews

Are Grape Solar panels more affordable than other brands?

Grape solar offers quality, high efficiency panels at a price point that makes sense for most consumers. 

When you install solar panels using grid-tied Grape Solar panel kits, you will be eligible for local rebates and incentives, so be sure to check what options your state or town offer. 


Best use

Cost (as of February 2022)

Where to buy

Grape Solar Polycrystalline Solar Panel GS-Star-100W

Providing backup power for RV and boat use



Grape Solar 300-Watt Off-Grid Solar Panel Kit

Powering small electronics like LED lights and fans


Home Depot

Grape Solar 400-Watt Off-Grid Solar Panel Kit

Providing more power to small electronics like power tools



Grape Solar 600W Off-Grid Solar Panel Kit

Powering larger electronics like mini-fridges and TVs



Grape Solar kits are a good choice:

  • For DIY solar projects

  • As portable solar panels for RV/motor home use

  • For on-the go battery charging

Although generally considered more affordable compared to getting solar panels professionally installed, make sure you do your research ahead of time before taking advantage of Grape Solar's pricing. If you end up needing help during the installation process, system upgrades and contractor fees can raise the price quickly, and the pros and cons of your investment must be weighed in the long-term. 

Check out SolarReviews' state-by-state rundown of solar panel costs

How does Grape solar compare to its competitors?

Comparing solar panel brands is best done by looking at the product warranties and the panels’ efficiencies. Let's take a closer look at Grape Solar.


Grape Solar offers several warranties for their solar panels. While specific warranties may vary based on products, customers can expect the following:

  • 5-year product warranty on materials and workmanship: This is less than many of the top solar panel brands like LG and Panasonic, which offer warranties of 15-25 years or longer

  • 10-year warranty that panels will provide >90 percent power output. Over time, a solar panel’s ability to absorb sunlight and turn it into power degrades, losing about .5% efficiency per year, but this warranty ensures your Grape Solar panels will still produce the necessary power after 10 years

  • 25-year warranty that panels will provide >80 percent power output

Generally speaking, the Grape Solar warranties are not the best coverage within the solar industry. The product warranty is short at only 5 years, so if your panels break on Year 6, you are out of luck. But the power output warranties are slightly better, ensuring that your panels will produce at least 80% of their original power after 25 years.


Like all solar panels, efficiency and overall performance will be influenced by your local weather conditions. 

Solar panels operate at maximum efficiency under specific temperature ranges. Most panels are tested at 77°F, and any temperature variance will change the panel's power output. This is known as the temperature coefficient. Say a panel has a temperature coefficient of -0.25%, it means that for every 1.8°F increase in temperature, the maximum power of the solar panel will decrease by 0.25%. The lower the coefficient, the less variance you'll see in your system.

Let's look at one of Grape Solar's panels for a better example. The solar panel model, Grape Solar GS-STAR-100W claims a temperature coefficient of -0.32%. This means that for every degree above 77°F the panel efficiency will decrease by 0.32%. So if a daytime temperature reaches 104°F on a hot day, the module's power output decreases by 8.62% because solar cells absorb less energy.

Grape Solar's solar panels have temperature coefficients that are higher than most panel brands, meaning they have slightly more power loss at high temperatures.

Can I install Grape Solar panels without a solar technician?

Consumers are well within their rights to install Grape Solar panels for their own home improvements without a contractor's help. 

If you choose to go the DIY route, keep a few things in mind:

  • Ensure that your home is not restricted from installing solar panels. If you own your home, this should not be an issue

  • Assure that you file the appropriate applications and permits for your town and state

  • You'll have to conduct your own assessments of the design and size of your energy system

  • You will be in charge of installation, maintenance, and electrical work

  • If you want to get your power system connected to your utility, you'll need a certified electrician to sign off on your system

While the DIY approach may be appealing to some, we recommend you consider your choice carefully. Certified solar installers can handle all of these details for you, such as proper permits and help you maintain your system over time.

Are Grape Solar panels right for you?

Grape Solar is one of the few solar panel manufacturers selling products to the public. They offer an affordable, durable selection of mid-range solar panel options that may appeal more to the DIY-minded person.

While it is possible to install Grape Solar kits on your house, we recommend just sticking with Grape Solar panels for use on a smaller scale, like camping and RVing. Buying the kits straight from Home Depot and Lowes is a feasible option; in fact, you can find how much you save when you buy a solar panel kit here.

You can purchase and install Grape Solar panels on your home by yourself but it might make more sense, both financially and for ease, to have professionals install them. If your goal is to power your home with solar, it usually makes sense to work with a licensed contractor that can fill out all the paperwork, determine how many panels you need, and install everything for you. 

Find out how much you can save by switching to solar

Written by Ana Almerini Marketing & Communications Manager

Ana is the Marketing & Communications Manager at SolarReviews, working within the solar industry since 2020. With a Master's in Climate and Society and professional experience in marketing, she helps communicate the value of solar to homeowners and build awareness of the SolarReviews brand. On weekends you can find her at the Jersey shore, reading a book from the ever-increasing stack on her side table, or eating food someone else cooked....

Learn more about Ana Almerini