Could digital circuit breakers make EV charging and home energy controls even smarter?

Circuit breakers can be found anywhere that electricity flows, preventing overloads from shorting circuits and starting fires. But the fundamental design of these electromechanical switches has changed little from the days of Thomas Edison, despite the rapid modernization and digitalization of the electricity world around them.

Atom Power CEO Ryan Kennedy hopes his company’s digital circuit breakers can break that century-old paradigm. Over the past four years, the North Carolina startup has designed and won UL certification for its products: semiconductor-based, software-configured circuit breakers that outperform their analog cousins on safety and flexibility measures — and pack the functionality of hundreds of other devices in one unit.

Atom Power got its first $3 million funding round in 2017 from Siemens, ABB and Eaton, and last year it raised $17.8 million from investors including ABB and Rockwell Automation. Siemens, ABB and Eaton are among the major manufacturers of circuit breakers for a global market that rakes in more than $10 billion per year, and Rockwell is a major maker of industrial control systems. That’s the market Atom Power first targeted when it rolled out its commercial products in 2019.

To be sure, Atom Power’s devices are quite a bit more expensive than the standard circuit breaker. That’s why Kennedy said the company focused its ​“initial commercialization outlook [on] some really high-value, high-impact customers,” such as data centers, manufacturers, and food and beverage processing facilities, he said. Kennedy characterized that as ​“the hardest market to check the box on first.”

Now, with those proving points under its belt, Atom Power is targeting two new markets that ​“lend themselves to exploit the full power of a digital circuit breaker,” he said in an interview earlier this month: electric vehicle charging and residential energy automation.

Shifting the ​“smarts” in EV charging from the charger to the electrical panel

EV chargers need to be able to communicate digitally with vehicles to ensure safe and timely charge-up of their batteries. They also need to network with the site hosts, utilities and grid operators to make sure that the combined charging loads don’t overwhelm the available electrical infrastructure. They must also modulate charging to match the demand-supply needs of the broader grid.

Today, those capabilities are contained in the charging pedestals themselves. Atom wants to move the smarts from the pedestals to the circuit breakers. As Kennedy pointed out, ​“You have to buy new circuit breakers to feed each pedestal anyway.”

Atom Power built its own stripped-down charging ​“pedestals” for Level 2 charging, consisting of little more than a reinforced steel tube with a cable and charging plug. It then embedded the digital control capability in the circuit breakers in the accompanying electrical panels that feed those pedestals.

That switch-out ​“saves customers a lot of money, but the most important aspect is the scalability and energy management,” Kennedy said. Today, EV charging site hosts are faced with choosing a charging device that’s meant to last more than a decade and locking themselves into whatever features and capabilities are built in at the time of installation. But with the Atom Power architecture, ​“you can program the system itself to be anything you want it to be, [and] the pedestal can look the same 20 years out.”

What’s more, today’s smart charging pedestals, which cost about $2,500 apiece on average, are ​“sitting out in the public, out in the rain and weather, exposed to vandalism, theft, cars running into them,” he said. The charging control capabilities of these chargers may also be compromised by network connectivity problems, depending on what kind of wireless communications they use and whether they’re blocked by concrete parking structures and other obstacles.

The circuit breakers, by contrast, are ​“sitting safely in the electrical room,” where they can communicate with each other to optimize charging across the fleet of chargers without risk of interference or losing signal. ​“We can throttle down the charge rate across any number of chargers,” he said.

This combination of factors should be able to deliver charging infrastructure that’s about half the cost of a typical system today, as well as bring more certainty to large-scale charging installations that need to carefully control and limit their total electrical draw to get permitted in parking lots and garages without expensive grid upgrades. While the commercial rollout won’t come until later this year, ​“we’ve been securing orders for those, and we’ve been negotiating some pretty big deals across several commercial fleets and multifamily applications,” Kennedy said.

Digitizing the circuits in all-electric homes

The second target market, residential electrical panels, one that Kennedy admits he ​“never thought Atom Power would be involved in.” That’s because cost is an overwhelming concern for this market, making a more expensive alternative a tough sell.

But as more and more homes add solar panels, batteries, all-electric heating and appliances, and EV chargers, the cost-versus-capability equation for analog circuit breakers is beginning to change, he said. These new loads and sources of power generally require significant upgrades to existing electrical panels in homes, bringing new challenges to utilities trying to maintain reliable grid service in neighborhoods that have them.

These pressures are driving solar installers like Tesla, Sunrun, sonnen, Generac and Enphase to add more energy visibility and control to their systems, and startups such as Lumin and ConnectDER to build add-on hardware with similar capabilities. Meanwhile, a number of companies are embedding digital technology into household electrical panels to manage these problems as well.

Span, the San Francisco–based startup led by former Tesla energy storage chief Arch Rao, has built a $3,500 digital home electrical panel that can monitor and measure individual household circuits. It also offers homeowners circuit-by-circuit control via smartphone app or online interface. Schneider Electric, a major maker of electrical panels, offers similar capabilities in the Square D Energy Center product it launched this year. Eaton has embedded digitally enabled circuit breakers into smart-home platforms such as sonnen’s ecoLinx.

These products are ​“trying to attack a specific problem — how do you effectively manage solar coming in, and energy being stored, behind a single panel? Without a single panel, you end up with this hodgepodge of stuff,” Kennedy said.

At the same time, being able to replace individual circuit breakers within a standard electrical panel with digital versions could offer a lower-cost and more flexible option for homeowners and contractors, he said. Specifically, Atom Power is working on versions of its circuit breaker that can ​“fit into new and existing homes in North America, that hit the high-value loads in the home” like HVAC systems, water heating and EV charging that have their own dedicated circuits.

Those account for about three-quarters of a home’s electrical load, making them a suitable target for spot replacement within an existing electrical panel. This also makes them a natural target for digital control to reduce loads on neighborhood transformers and circuits, or to tap for demand-response programs seeking to shave peak demand on the grid.

Once again, the higher cost of Atom Power’s devices compared to traditional circuit breakers is a barrier, Kennedy conceded. But as household loads grow in intensity, the cost of alternative methods to manage them, like upgrading entire electrical panels or integrating multiple devices to keep individual loads balanced against a home’s existing electrical circuitry constraints, should bring a higher-priced alternative into parity, he said.

Atom Power develops the silicon carbide semiconductor devices at the core of its digital circuit breakers, giving it quite a bit of control over fine-tuning and improving its products for new applications like this, he said. Residential prototypes are being tested right now, and the company is planning a mid-2022 release date for a commercial product.

Target markets include ​“smart” panel makers like Span, as well as developers of home distributed energy resources like solar and battery makers, as well as utilities that are interested in using its circuit breakers for demand-response and load-control applications, he said.

With built-in revenue-grade metering embedded into each device, ​“a utility could say, ​‘I want to offset 50 megawatts,’ and a utility could measurably say, ​‘Boom, 50 megawatts are off the grid,’” he said. ​“We’re not trying to take over the [distributed energy resource] market. We’re trying to contribute to it.”

(Article images courtesy of Atom Power)