grape solar panels

Should you buy Grape Solar panels from Costco or Home Depot?

Installing solar panels is fast becoming a home improvement project that any homeowner can take on. Now that you can buy solar panels at Costco and Home Depot, you may even be considering installing a home solar energy system yourself. One of the most popular DIY options is to purchase a solar panel kit from Grape Solar, an Oregon-based solar panel manufacturer whose products are for sale at Costco and Home Depot. But before you make a Costco solar purchase, we recommend you learn more about how Grape Solar panels compare to other solar panel brands.

How Grape Solar reviews compare to other panel manufacturers

There are four key metrics to consider when evaluating solar panel quality: (1) panel efficiency, (2) warranty, (3) performance, and (4) price. To help you understand Grape Solar panel quality, we’ve analyzed the technical specs of their panels and compared them to other leading panel manufacturers offered on the EnergySage Solar Marketplace.

1. Efficiency

Solar panel efficiency refers to how well your solar panel can convert sunlight into usable electricity. A higher efficiency rating is better, because it means that your solar panel is able to convert more of the sunlight it captures into electricity. The best solar panels available on the market today operate at approximately 22 percent efficiency.

The graph below shows how Grape Solar panels measure up when compared to 24 of the most popular solar panel brands offered to solar shoppers on the EnergySage Solar Marketplace. As you can see, the most common solar panels out there fall between 14 and 18 percent panel efficiency, and Grape Solar panels fit comfortably within that range. Our review of Grape Solar panels found that they have an efficiency rating of anywhere from 14.63 percent to 18.4 percent.

2. Temperature Coefficient (Performance)

The temperature coefficient tells you how well your solar panels will perform in less-than-ideal conditions. Solar panels are like any other kind of electronic equipment: they operate most efficiently when they are kept cool (ideally around 25° C or 77° F). The temperature coefficient gives you a sense of how your panel’s performance will degrade during hot summer days. For every degree above 25° C, your solar panel’s electricity production will decrease by the temperature coefficient.

For example, Grape Solar’s GS-S-160-Fab8 model has a temperature coefficient of -0.5. This means that if your solar panel’s temperature increases by one degree (from 25° C to 26° C), its electricity production will fall by 0.5%. If the temperature increases to 35° C (or 95° F), Grape Solar panels will produce five percent less electricity. While 95° F might seem high to you, remember that the surface of your roof can get much hotter than the air around it when the sun is beating down on it.

A lower temperature coefficient is better, and the best solar panels available on the market have a temperature coefficient of -0.25. Grape Solar panels have a temperature coefficient that ranges from -0.45 to -0.38, which is near the mid-range seen in the EnergySage Solar Marketplace.

3. Warranty

Whether you’re buying a new TV, a car, or solar panels for your roof, you should expect that the manufacturer will stand behind their product with a strong warranty. A solar panel’s materials warranty (sometimes referred to as the product or equipment warranty) protects you against equipment failures due to manufacturing defects or environmental issues. Most companies, including Grape Solar, offer a 10-year materials warranty, but the best solar panel manufacturers will guarantee against equipment failures for 15 or even 25 years. For example, on EnergySage approximately a third of the panels offered by our top 25 manufacturers come with a 25-year warranty. Grape Solar’s warranty is right in the middle range of the marketplace, at 10 years.

4. Price

Perhaps the most important question of all – are you going to save money when you buy solar panels at Costco or Home Depot? How does the cost of Grape Solar panels compare to other panel brands?

As of January 2020, buying a 5,300-watt (5.3 kilowatt) solar panel system at Home Depot will cost you $10,942 before any tax credits or other financial incentives. Subtract the 26 percent federal tax credit for solar, and you reduce your equipment costs to $8,097. However, these off-the-shelf prices for Grape Solar panels don’t include installation costs, and not every state allows you to connect DIY solar installations to the grid. By comparison, on EnergySage, a fully installed and grid-connected 5 kW solar panel system costs, on average, about $10,952 after the 20% federal tax credit, depending on where you live.

Don’t need a 5 kW system? Home Depot also offers a 3,180-watt (3.18 kW) solar panel system for $6,909. Again, subtract the 26 percent federal tax credit – your equipment costs are now $5,157. By comparison, you can get a fully installed and grid-connected 3.5 kW solar panel system on EnergySage for a similar price as well.

Of course, the price that you end up paying for your solar panel system depends on the equipment that you choose. Grape Solar manufactures mid-tier panels for a reasonable price, but they are not the cheapest solar panel prices we’ve seen offered. As with any major home improvement decision, you should always compare prices and reviews for multiple products before you make your purchase. You can easily evaluate solar panel quotes from qualified solar installers side-by-side on the EnergySage Solar Marketplace to see how a Grape Solar panel kit stacks up against the competition.

Should you buy solar panels at Home Depot or Costco?

If you’re looking at Costco or Home Depot solar panels, Grape Solar will be one of your only options. Why is this? Most solar panel manufacturers don’t sell directly to consumers, but instead sell their products to solar installation companies via distributors. This means that many of the industry-leading solar panel brands, like SunPower and Panasonic, just aren’t available for you to buy directly at the hardware store – you need to work with a local solar installer that offers those products.

Finding someone who knows what they’re doing can actually save you both time and money. Some of the best solar installers have been installing solar energy systems for decades – experience that no amount of online research or DIY guides can replace.

Your solar installer will also help you complete and file the permits and applications that you’ll need to submit to get your solar energy system up and running. Even if you’re ready and able to do all of the installation work yourself, you’ll still need to find a certified electrician to sign off on your work before your utility will allow you to connect your new solar panel system to the grid.

In the end, there are still some cases where DIY solar makes sense. If you’re looking to install a small PV system, and comfortable doing your own electrical work, and not prohibited from installing your own system, then buying your solar equipment online might be just what you need. In these situations, buying Grape Solar panels can be a reliable, no frills option. Compare several options beforehand, and click the retailer link on the table below once ready.

Grape Solar DIY buying options

ProductSystem Size (Watts)System CostDollars per WattRetailer Link
Grape Solar grid-tied solar PV system5,300$12,009$2.26Home Depot
Grape Solar grid-tied solar PV system3,180$7,332$2.30Home Depot
Grape Solar grid-tied solar PV system2,300$9,238$4.02Amazon
Grape Solar off-grid solar PV system480$1,199$2.50Amazon

Note: This post contains affiliate links. We only link to products that we think are great.

6 thoughts on “Should you buy Grape Solar panels from Costco or Home Depot?

  1. Hope

    My self I want to build a plant shade shed four feet by six feet to be used by plants nine and a months a year.
    2 1/2 Months as an out door enterment center. I like the higher quality big brand names. The solar panels I am interested in the shipping cost more than they do. I am interested in Canadian Solar and the solar panels made in Norway they are more reinforced to deal with both snow and hail. I am new to solar and slowly learning about solar engery. At the time I am considering a 24 volt system, two to four solar panels that are in the range of 300 to 400 watts, I see where the shade shed could be used for plants and a deep cell battery recharging station!

  2. Kelly Clover

    Their solar panels are OK but the GS-PWM-165W charge controller which appears in several of their kits as well as separately is something I would recommend AGAINST regardless of the size or intended size of your solar array. The major objection I have is the difficulty of hooking up your wires to the charge controller. Their manuals recommend gauge 10 wires for small arrays, but such wires cannot be hooked up so easily the way they have the charge controller designed. Among other things I think there is danger of a short circuit because they don’t give you enough space to work with in hooking up the wires. The charge controller WORKS if you can manage to get the wires in but they don’t make it so easy.
    Windynation uses a P30L charge controller in its 100 watt kit. This is a better deal from the standpoint of making it easy to hook up the wires.

  3. jason pippin

    There is for sure a biased opinion here in this article. Combining all other mfg specs to compare to the Grape Solar is a little off kilter don’t you agree. I currently own three Grape Solar GS-Star 50 watt poly solar panels, and hands down they are out performing the three Renogy poly panels that I used to own. As far as weither or not to purchase them from Cost co or HD…that all depends on how deep your pocket is. Been my experience with solar companies that they try to sell you things that you simply just dont need. I am all for making a profit at your business, but trying to sell me a 10k system to do the job of a 1500 dollar system is a little on the extreme side.
    As for your article,,it was a fun read and gave me a good chuckle. Alot of misleading info here. But…you have to make a living right????

  4. Adam

    These are good panels for $90 free shipping. They are Poly but Mono’s are going to run you $130. If you don’t have limited install space I would recommend these.

    For any large installations you want to go for 24v panels. This panel only runs $55 in 24v form.

  5. TB

    What does taking a vacation have to do with solar panels in general ?
    Anyway I am looking to expand an existing solar installation and researching the marker for just the panels.
    300 watt panels from Costco or Home Depot might be cost effective due to the no shipping costs. Granted the shipping cost is likely factored into the overall price. HD has a 4 pack at apx. $1500 or 375 ea.
    For example the Wholesale Solar warehouse has similar items priced around $300 but shipping costs come into play

  6. Nelson Gibson

    Oh, wow! Where do I begin? Who pays your salary? There is an obvious bias in the article. The graphs in the first two sections on efficiency and performance do not support your claims. You include the graph lines from other manufacturers lumped together as a whole and compare them to a Grape Solar Panel from Cost Co or Home Depot. One panel might have high efficiency specs and poor performance or vice versa. I could comment further, but that should be enough for you to rethink the article.
    However, I tend to agree with your conclusion. Buying panels at Cost Co or Home Depot piece by piece is not a wise investment.
    I am a retired electrical engineer. I plan to start a DIY 4.5 kW solar panel installation maybe the end of this year or next year. I am doing my research now.
    This year I am taking a 40 day Australian cruise and a month travel vacation traveling in the USA. That is in addition to two months vacation in the Bahamas. And, yes, I do have my priorities in the correct order. (Smile.)
    Happy New Year to you. May all your resolutions for 2018 come true.


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