Stone Edge Farm Creates an Energy-Independent Island

July 25, 2016


Here at home we’ll play in the city

Powered by the sun

Perfect weather for a streamlined world

There’ll be spandex jackets one for everyone

– “IGY,” by Donald Fagen

Solano Avenue heads west from Maxwell Farms Regional Park toward Sonoma Mountain, through a rural residential neighborhood with fewer and fewer houses. Where it ends, a gate blocks the entrance to a 16-acre estate, lined by stone fencing dating from its days as a sheep ranch.

What’s behind the gate now is nothing less than the future: an energy self-sustaining “island” of seven solar arrays, at least four types of storage batteries, a utility-grade computer controlling system, even an electrolyzer to split water into its component parts, hydrogen to supply power and oxygen to… well, to breathe.

Welcome to SEFMG, or the Stone Edge Farm Micro Grid.

Recently a 25-person delegation of solar engineers and policy wonks from the InterSolar North America Conference in San Francisco, a networking event that drew about 10,000 people from around the world, bussed up to Sonoma to tour the estate, on the promise of an opportunity to see a solar winery.

But they got a lot more than that: a two-hour tour of a state-of-the-art energy microgrid, one capable not only of drawing from the regional power grid that supplies energy to homes, businesses, factories – everything that runs on electricity, which is just about everything – but of supplying energy back to the grid… and doing both simultaneously.

Or, if the situation requires it, to self-supply and regulate its own power needs, to become an “island” in the sea of energy.

“Moving distributed energy forward, one microgrid at a time,” boasted the display backdrop at InterSolar. Though it’s an integrated collaboration of several vendors – ESS and Enphase and Aquion and DC Systems, even Tesla (the sexiest brand name of the bunch) – it’s driven by John “Mac” McQuown. Now in his early 80s, McQuown is a former Wells Fargo Bank investment director who led the development of the index fund model – but even in retirement he continues his engagement in remaking the world.

He and his wife Leslie moved to the Sonoma Valley about 20 year ago, attracted by the 400-year-old trees on the then-remote sheep ranch, and the deep connection with the land they promised. They took over the property, and added a couple neighboring lots to it, to create Stone Edge Farm. It now sustains heirloom vegetables, olive groves, fruit trees, ornamental plants, herbs, chickens, even beehives.

In 2004, they started developing a sustainable vineyard on the property, under the direction of organic vineyard pioneer Phil Coturri and winemaker Jeffrey Baker; Stone Edge Wines rapidly elevated to a world-class organic winery – its low-production, Bordeaux-driven wines sought-after and valued. The winery even has its own private restaurant, Edge, on East Napa Street, presided over by award-winning chef John McReynolds.

Clearly, the McQuowns don’t do things in half-measures.

Just over three years ago, concerned about climate change, they decided to reduce the carbon footprint of Stone Edge Farms as low as possible, vowing to cut it by half in three years – a goal they met in a single year. Now, they are within reach of getting not just to zero emissions, but even into negative territory. Like the old limbo rock song went, “How low can you go?”

They are finding out. The microgrid they’ve built, under the technical supervision of Craig Wooster, is complex but elegant, a network of photovoltaic solar arrays and diverse battery banks, even alternative power generators like an electrolysis unit that “cracks” water into hydrogen to power fuel-cell cars like the Toyota Mirai with zero emissions, one of several futuristic cars (and a few classics) that McQuown keeps in his garage.

This array can ultimately work together to create an energy island, one self-sufficient enough to operate entirely independent of the larger grid that most of us draw our juice from. It’s all organized by coordinating software from DC Systems, the same company that PG&E uses to manage its utilities.

“We have a real-world laboratory here, and we’re altering the energy paradigm at so many levels,” Wooster said. He cites the development of software and infrastructure to take this microgrid to a new level.

Energy independence at Stone Edge Farm

The InterSolar delegates toured the grounds in three groups, alternately dazzled by the property’s landscaping, structures – including a three-sided pyramid and a personal observatory – and intrigued by the high-tech innovations around every corner. They weren’t just along for the tour, though – they grilled the interns who demonstrated the technologies with grad-school questions about inverters and thermal runaway and the difference between lithium iron phosphate and your basic lithium ion batteries.

“We’re doing things here that haven’t been done before,” said DC Systems CEO Doug Campbell at the Ramekins-catered lunch that accompanied the tour. “From a control systems point of view, this is unique.”

Not so unique that it doesn’t have real-world applications. Wooster recently signed a memorandum of understanding with the Sonoma Valley Unified School District to develop a microgrid there, and to sell its PV-generated power back to PG&E during peak hours. It would also allow the school to function as an energy island, a safety zone during any disruption to the power grid – much the same way that Stone Edge Farm was recently able to declare its own “energy independence.”

And given McQuown’s own wealth, which makes him an island unto himself, it’s refreshing the entire project is being developed as open-source, without copyrights or other restrictions.

It leads to the inevitable question, what does the future hold in store?

Campbell – despite his deep ties to regional power utilities – casually predicts, “In 50 years everything will be self-powered.”

Maybe we’ll all be islands, cut loose from the power plants and coal mines and atom-splitters and dams, powered by the sun, in perfect weather for a streamlined world… spandex jackets not required.

Contact Christian at [email protected].

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