When Tesla Motors Inc. came knocking, one cellar door flew open.

Jackson Family Wines of Santa Rosa, Calif., was one of the first businesses to put Tesla’s TSLA, +4.42% commercial energy-storage batteries to use, a move the wine company’s chief operating office Hugh Reimers called a “very easy decision.”

The story of how two of California’s favorite industries — wine and technology — came together began in 2012.

Jackson, which makes the Kendall-Jackson wines and owns wineries in California and Oregon as well as Australia, Chile, France and other countries, had worked with an energy-management company that introduced the idea of using the Tesla batteries as part of a pilot program. The batteries would be installed free of charge, and the winery agreed to keep it all confidential until Tesla was ready to announce the new product.

“We got together with Tesla and the thing we loved about Tesla was that we had a lot of the same goals in terms of energy management,” Reimers said. The winery had already installed solar-power systems to supply some of its power needs, which vary throughout the year and are mostly tied to refrigeration.

Tesla late last month unveiled Tesla Energy, its stationary batteries for home, commercial, and utility-scale use.

On a conference call last week after Tesla’s first-quarter results, Chief Executive Elon Musk called demand for the batteries “crazy off the hook” and said they are essentially sold out through mid-2016.

See also: These are Tesla’s main rivals in the energy storage business

Jackson Family Wines now has 21 of Tesla’s batteries in six of its wineries in northern and central California.

Together, the batteries provide 4.2 megawatts of storage capacity, and the winery uses the batteries mostly in two ways: to shift loads, or switching to the batteries when using power during the most expensive part of the day, and to smooth out its demand peaks.

“It’s been a pretty turnkey experience,” said Julien Gervreau, with the winery’s sustainability department. Tesla paid for the installation, which was completed late last year.

“Our tab was a whopping zero dollars,” Gervreau said.

The catch? Jackson Family Wineries has to split any of its energy savings with Tesla. That gives both businesses “skin in the game,” Gervreau said. The winery estimates its portion of the savings will be about $200,000 a year.

The wine group had been researching ways to conserve energy for some time, and it has installed solar-power systems in a number of its wineries. In the future, the company could create a microgrid to take advantage of solar and batteries, Reimers said.

“I hope (the batteries) become popular … we would not hesitate to do it again,” he said.

Being a seasonal business, the winery’s energy needs vary, and are mostly connected to refrigeration. Peak need is during harvest time, from early September to late October in California, when tanks of fermenting wine need to be kept cool. In the summer, the wine company needs some refrigeration for wine storage, while its electricity demand drops during the cool winter months.