Meet Thorvald, an autonomous, electric vineyard robot.

If you’re picturing a cute, sci-fi robot like R2-D2 or Rosie from the Jetsons, it isn’t quite like that. Thorvald looks more like an airport magnetometer on wheels that fits over the vines.

The device is equipped with cameras to collect data as it goes along, and its advanced satellite technology — called RTK — helps it navigate the rows with remarkable precision.

“So, it goes up and down the vineyard rows using UV-C light, so really low doses of UV-C light, to disrupt mildew and Botrytis spores,” explained Caine Thompson, the general manager at Norway-based Saga Robotics. “It’s done at night because the research shows that if a two- or three-hour period of darkness follows a UV light application, the powdery mildew does not have time to naturally repair itself.”

Thompson compares Thorvald to a kind of Roomba that keeps fungal diseases from developing and spreading, all without using chemicals or adding to carbon emissions.

The technology was originally used to treat strawberry crops in the UK and was later adapted for vineyards. This year, it’s making its North Coast debut.

“There's a lot of interest, I think, in California,” Thompson said. “What's uniting amongst growers and wineries is that they really want to farm more sustainably.”

That includes Silver Oak winery in Napa Valley. For the last few months, the Oakville winery has been testing Thorvald in a 10-acre Sauvignon Blanc vineyard.

“So these will turn on around 8:45 at night and then it'll automatically start going up and down the vineyard rows,” said Thompson, adding that the robot travels at 2.3 miles per hour.

After a couple months of nightly treatments in this vineyard, Thompson said he can see — and smell — the results.

“Usually at this time when you walk into a vineyard, you can smell the leaf and it will smell of sulfur or some form of chemical,” he said. “Whereas you walk in here now, you pick up a leaf and there's no smell of any sulfur or anything, which is pretty amazing.”

Not only that, Thompson said, the grape clusters look pristine.

“If it had a fungal issue, you would see white powdery spores around the bunch and you'd actually start to see cracks and slits in the skins,” he said, “and you'd see the fruit not ripening.”

Norm Peters, the head of vineyard operations at Silver Oak, said Thorvald is doing a great job controlling fungus in a high-mildew year — though he admits the ‘bot is not so great at navigating hillside vineyards.

“There's been hiccups just like any spray program on hills, but there's another model I'm told that will really get those hills next year,” Peters said. “But on the flatland like this, we've been super pleased with it.”

Though Thompson says human labor will always be important in viticulture, autonomous robots have the potential to help with everything from estimating crop yields to controlling pests and weeds without chemicals.

“[In] the future of farming,” he said, “I think robotics is going to play a big role.”

If Thorvald could talk, he’d probably agree.