Grape Solar

isn't the largest solar panel maker in the world, but it does seem to understand retailers.

The company -- which assembles panels in Oregon with components sourced from a wide variety of suppliers in China -- will soon begin selling its panels at Home Depot locations. A  formal announcement is due soon.

It's a notable accomplishment, as solar -- and a plethora of solar brands -- are not as prevalent at large retailers as you might think. It takes time and a certain degree of retailer tribal wisdom to earn shelf space at many of these places.

As reported in April, Grape already sells complete solar systems and panels through Costco and Amazon. While both retailers sell small solar panels and devices, Grape is the only brand available on the websites of both Costco and Amazon for complete residential solar systems. (You can also go to Costco and touch and buy the Grape systems, according to my neighbor.)

Home Depot's website currently offers a few kits featuring individual Sharp panels and offers solar leases through SolarCity, but the available selection is nothing on the scale that one might expect from the big-box behemoth.

If you happen to be shopping at the moment, Costco offers a better deal. The 5-kilowatt bundle there costs $16,999 while at Amazon it sells for $19,999. Costco's web site strongly recommends hiring a professional installer. Amazon is a little more cavalier.

"The Solar Power System comes complete with everything you need to rack-mount the 22 solar panels on your roof," says Amazon's site. "Should you decide to expand the array, connecting additional kits is easy."

Home Depot and Lowe's, needless to say, are two of the ultimate channel partners for green home companies. Getting shelf space at either store won't guarantee success, but it certainly creates an opportunity to get close to consumers. Home Depot sells LED bulbs from Cree, Philips branded under its own EcoSmart label, and recently started offering Wi-Fi smart thermostats from Radio Thermostat a few months ago.

Lowe's, meanwhile, has alliances with Westinghouse Solar and has invested in energy retrofitter Recurve and solar installer Sungevity.

And expect more from Costco too. Back in June, Ken Lowe, the founder of Vizio, told us that his company would soon come out with LED bulbs. A few years ago, Vizio was an unheralded, unknown TV manufacturer. After teaming up with Costco, sales zoomed. It is has since become the most popular TV brand in the U.S. for two years in a row. These two companies like each other quite a bit and Costco tends to have a loyal, strangely upscale, clientele. (I interviewed the CFO and CEO at Costco once about hot dogs and patio furniture. It's quite an interesting operation.)

Wal-Mart currently does not appear to offer residential solar systems on its website, but check out this 225-pound solar-powered barrel feeder with varmint zapper for $129.

in Japan, Softbank founder Masayoshi Son said his company would begin to build solar power plants earlier this year.

Besides residential systems, Grape also participates in commercial-scale solar projects.

The company used to be called Centron Solar, but founder Ocean Yuan changed it after getting a legal notice from Germany's Centro Solar. The Grape name comes from the fact that the company gets its components from a cluster of manufacturers near Shanghai. Yuan emphasizes that the company has a horizontal business model, leveraging suppliers, rather than a vertical one in which a single company produces its own wafer, cells and modules.

Grapes and the sun also have an affinity.