Within the next few months, Vermont’s largest electric utility will begin replacing conventional electric service panels in 100 carefully selected homes with a reinvented version that gives customers unprecedented control over their use of electricity.
Green Mountain Power thinks the recently announced pilot program—one of the first of its kind in the U.S.—holds promise not only for the customers who get the devices but also for the utility as it steers itself toward a fully clean-power future and a modernized grid.
A standard service panel controls the flow of electricity with a number of individual breakers that are either on or off. The Span Smart Panel is an interactive device that lets customers control power to individual circuits via a smart phone app, as well as manage the distribution of power to other devices, such as electric vehicle chargers and solar battery storage. The smart panel also can meter the use of electricity, replacing conventional meters now in use.
Customers chosen to be part of the rollout will get the smart panels installed for free. It’s a $500,000 bet that Green Mountain Power (GMP) is placing on a new technology that will help it remake the grid. The company, a privately held utility serving some 266,000 residential and business customers in Vermont, has already launched programs to promote the installation of Tesla Powerwall batteries and electric vehicle chargers as it pushes for a carbon-free grid by 2025.
The utility says those programs already are paying off. The thousands of Tesla Powerwall batteries it has installed in the homes of customers gives it a source of stored energy during times of peak demand, and helped save Green Mountain $3 million in 2020.
As more homeowners turn to solar panels, electric vehicles, heat pumps, and battery storage, managing the distribution of electricity becomes more important.
In a press release describing the pilot program, GMP President and CEO Mari McClure said a smart panel would alert customers when the power goes out and allow them to manage backup electricity from a battery remotely via a smart phone.
The potential flexibility of the system should be a big draw for customers even as it helps the utility, GMP communications director Kristin Kelly said in a telephone call:
“If you’re looking at a future where customers have an electric vehicle, heat pumps, solar, battery,” she said, “all this stuff happening in the home on the electrical system, wouldn’t it be awesome if there were once device that could help manage all of that for the customer and the utility without a lot of upgrades and changes.”
Kelly said GMP would be looking for several types of customers: some who already have installed solar panels, some with electric vehicle chargers, some with battery storage, and even those with just an electric water heater. The intent is to see how the panel works in different scenarios. Installation crews already have been trained, Kelly said, and the first of the panels could be going in by June.
In its filing with the Vermont Public Utilities Commission, the utility said the pilot program was part of an ongoing effort to introduce new technologies and lower costs for consumers. “As we continue to innovate on behalf of our customers, GMP is always looking for hardware, software and services that can deliver solutions to improve reliability, reduce carbon and reduce cost for all,” Craig Ferreira of the utility’s innovation development arm wrote. “As more devices in the home gain the ability to help with load management, creating a central gateway, or access point, will help to reduce the number of one-by-one integrations needed, providing greater ease and flexibility for both our customers and GMP.”
Ferreira said the utility has been watching the development of smart panels for several years. Span, he said, is the first company to develop a UL-certified panel with all of the monitoring and control features it wanted as a full replacement for traditional panels. (For a look at the utility’s full PUC filing, read Span filing).
“As people switch to solar and install more and more solar and more and more batteries and switch to EVs, they are going to need to do electric upgrades,” Kelly said. “They’re going to want more control over these systems and the current electric panel doesn’t always accommodate all of that. As a utility that’s already in the space of storage and electric vehicles and all of that, it’s a natural fit. It’s a different way of looking at things. So we’re trying it. We’re already on that transition path anyway.”
Living with a Span panel
Adding a battery to a PV system keeps the power going for key appliances or circuits when the grid goes down. In an article posted at Wired, however, Christopher Null listed the shortcomings of these systems, including an inability to change loads when circuits are hard-wired, and what he called the “poor visibility” that the inverter’s app provides into total power consumption in the home.
After posting his complaints in an earlier article, Null was approached by Arch Rao, CEO at Span and former head of product at Tesla. Rao offered to replace Null’s conventional service panel with a Span panel.
Sure, Null said. Installation took about nine hours, after which Null could settle in with the Span app and begin learning how to use its new capabilities.
“It didn’t take long to see exactly how much I had been missing” Null writes. “The primary screen within the app shows where power is coming from (solar, battery, or grid), and where it’s going (to the home, back to the battery, or back to the grid), all in real time. From there, it’s easy to drill down and get insights into (almost) every circuit in my home, detailing each circuit’s current power draw and, as time went on, how much power each circuit is eating up.”
More important, the panel allowed Null to control how power from the battery is being used. Circuits are divided into categories—must have, nice to have, and not essential—and swapping circuits into another category is simply a drag-and-drop operation in the app, he said.
Although he had some quibbles with the system, including a retail price tag that can range from $6,000 to $7,500, Null called the system a “long-overdue” product that could shake up a stodgy industry that hasn’t seem much progress since the 1960s.
The three-year-old, privately held company would not discuss sales figures, but through a spokeswoman said that it has been installing panels in homes around the country since the summer of 2020. It closed on a $20 million round of funding in January. In addition to the Green Mountain Power project, Span also is partnering with Silicon Valley Clean Energy to install panels in the SVCE service area as part of an effort to reduce natural gas emissions.
For the record, there’s a note at the bottom of Null’s article disclosing that the panel was installed for a “nominal fee” and that it would not be returned after the review was published. Further, Wired says it may earn a commission when readers buy products using links in published articles.
Scott Gibson is a contributing writer at Green Building Advisor and Fine Homebuilding magazine.