First off-grid home in the city of Napa nearing completion | Local News

The Pueblo Park house, when finished in May, will use SunPower solar panels for all its electrical needs and lithium-ion batteries — five Tesla Powerwalls — to store that energy, with no connection to the Pacific Gas & Electric Company grid.

“So basically, rather than having a traditional connection to a utility company your home acts as its own utility company,” Slarve said. “Instead of a grid-tie, you’re using the sun. You collect it during the day, you throw the energy into the batteries and then, throughout the evening, the batteries supplement all your power needs.”

Slarve said he was partially motivated to go off-grid because of the estimated amount of time it was going to take for PG&E to connect the house. A PG&E representative told him three months after he submitted an application that it would take another nine to 12 months to energize the property, he said.

Deanna Contreras, a PG&E spokesperson, said she couldn’t comment about a specific property. However, she said, the length of time for PG&E to establish a new connection depends on where the project is located and the amount of power needed. Generally, she said, customers submit an application for hooking up power to PG&E’s website, a customer representative works as a point of contact, and an estimated length of time to finish the project comes out of that process.

“Service connection times vary depending on the complexity of the project and the number of projects PG&E has in progress, and we aim to provide realistic project timeline estimates,” Contreras said in an emailed statement.

Going off-grid enabled Slarve to speed the process of getting power up. Vacaville-based Ambrose Solar managed to install the solar panels and hang the batteries in roughly two weeks, he said, and the city of Napa’s building division finished up a final inspection in about a month.

But, Slarve said, the primary reason he decided to pursue the off-grid project was because the house will serve as a proof of concept for his construction company, and will give him energy-use data that will help it figure out similar projects.

Slarve Construction generally focuses on building aesthetically pleasing, energy-efficient homes, he said, and uses methods such as spray foam insulation to help achieve that efficiency. The off-grid home was designed to fit into that focus, as will a second off-grid home he’s planning to build on his Napa property next year.

“I want to have an example of real-world data of what it’s like to use high-efficiency building materials coupled with battery and solar and see what the actual rates turn out to be,” Slarve said. “Really, it’s about trying to go where the puck is flying versus doing what we’ve traditionally done.”

Going off the grid isn’t a new idea, but it’s become increasingly feasible over the past decade because the prices of solar panels and batteries have fallen considerably. That’s enabled an increasing — though still small — number of Californians to build off-grid homes out of frustration with rising power costs, PG&E power shutoffs, and wildfires caused by the company, according to a report from the New York Times.

Slarve said living off the grid is currently “on the edge of practical,” and still contains some less-than-ideal aspects. The energy system for his home — which is overbuilt, he said, to help with data gathering and ensure the system works out — cost about $130,000 without taking into to account any solar tax credits. With a 26% federal solar energy tax credit, the cost ended falling to around $100,000.

He said the cost of the system, though high, should ultimately be offset by energy savings over about the next decade. He will need to maintain the system himself, however, and any problems it has will be his to manage.

“It’s interesting to have something independent, completely isolated from blackouts,” Slarve said. “I guess the issue is, as you become your own utility company, you have to maintain your own utilities as they break down. If something breaks down in the middle of the night there’s no crew of drivers ready to respond.”

Vin Smith, the city of Napa’s community development director, said he’s heard there are a few off-grid homes in Napa County, but he’s not aware of any beyond Slarve’s home in the city. There are several electrical backup systems in the city, he said, which kick in only during power outages.

Off-grid systems are more common in the county’s less populated areas. A Calistoga couple decided to opt for such a system in 2020 after enduring sometimes week-long power shutoffs in 2019, according to reporting from The Weekly Calistogan.

David Northup, sales manager for Ambrose Solar, said he’s seen an increasing amount of interest in solar power and battery systems over the past several years, for a variety of reasons. For example, he said, people have shifted to working from home because of the COVID-19 pandemic, and a sudden power shutoff may cost them a lot of money.

“We have a ton of clients that request batteries or general knowledge about batteries,” Northup said. “I would say for my sales reps almost every appointment batteries are being bought up and discussed. They’re great for consumers. It really is a peace of mind for them knowing that if PG&E’s grid goes down they have the batteries to back their power up.”

David Giudice, Napa County code compliance manager, said the county isn’t currently involved in approvals for off-grid homes, though he’s aware of a few cabins on the east side of Lake Berryessa that fit that definition.

Giudice added that, because of the increased interest and feasibility of building an off-grid home, the county is in the process of developing standards for such homes. All homes are required to meet health and safety codes, he said and any home that theoretically meets those requirements could be approved. But the county has some concerns about off-grid homes running out of power if there isn’t enough sun for a period of time and the home’s battery pack doesn’t store sufficient energy.

“We’re definitely looking into off-grid homes,” Giudice said. “We know it’s going to be an issue, and as the technology improves we’ll see more interest in that.”

Northup said Slarve’s house was actually the first off-the-grid home they’ve helped build, mostly because there are several barriers in the way of finishing such a project. For one, it’s very difficult for houses that are already hooked up to PG&E power to go off the grid, he said. Another difficulty is cities or jurisdictions that don’t support such projects.

Financing such projects can also be a challenge because most lenders require PG&E to be involved with solar projects, Northup said.

“Me and my wife, we bought a new build in Winters and they have service from PG&E so there’s no way to go completely off-grid like Alex did,” Northup said. “If I had the opportunity, I’d be taking it. I think it’s awesome and this project has been an awesome experience from start to finish.”