The continued push toward electrification creates a need for technologies that provide a way to integrate distributed energy resources (DERs) into the power grid, certainly at the residential level where electrification will likely have the greatest impact.
Electrification of everything in our everyday lives is a key step in the global transition to clean energy. This shift requires increased flexibility in the current power grid’s infrastructure to accommodate the integration of more renewable energy sources, including the addition of distributed energy resources (DERs). It also requires enhanced load management.
The current system is not designed to integrate DERs in a way that is effective and scalable, particularly in residential settings. What is needed is a nimble, adaptable technology at the edge of the grid that allows for two-way communication between the power source and the user, and that can quickly respond to changes in the power system in real time. Enter the circuit breaker, a technology that hasn’t changed tremendously in the past 80 years. Until now.
Challenges to DER Integration in Residential Settings
Declining costs and wider availability of DER assets such as solar panels and battery storage are making it possible for homeowners to invest in these technologies to produce and store power in their homes. However, homeowners who want to integrate multiple DERs face significant challenges, including the infrastructure of the home itself.
Despite increasing interest in residential solar and home-based energy storage, the utility industry has not changed how it wires and connects neighborhoods to the power grid. Utilities continue to build out capacity for new neighborhoods under the assumption that the homes in those settings do not have the capacity to produce or store their own power. DERs are seen as “nice to have” solutions and there’s no guarantee that they will work. This can leave homeowners who install solar panels quite literally “in the dark” should the power go out, because if they cannot disconnect their power supply from the utility, their solar power goes out, too. While disconnecting from the grid is an option, it can be expensive and prohibitive to invest in the infrastructure needed to back up every load in the home.
Another infrastructure-related challenge to DER integration involves how the home is wired. The current industry standard for adding DERs is a discrete wiring method. Once the system is set up, it’s fixed. If a homeowner wants to add multiple DERs, such as a solar array, battery storage, and an electric vehicle (EV) charger, they will need to rewire their home’s power system and install additional hardware to ensure the system is connected and the DERs can communicate via a center hub. This can be an invasive and expensive undertaking.
Capacity also is a challenge when EVs come into play. In the U.S., utilities have fixed power capacity to deliver to each home they service. On average, it is 200 amps per household. Homeowners who install an EV charger may need to get a service upgrade from their utility to accommodate the increased capacity needed to manage their loads. This necessity can lead to higher costs borne by the homeowner.
Even so, adding DERs to homes and communities is of value to utilities. More electricity generated within a home or a neighborhood would mean less electricity transmitted by the utility. This would help delay the need to increase system capacity and save money that would otherwise be spent on rebuilding the grid to meet additional demand.
Despite these challenges, technologies are being developed today to support DER integration in the power grid of the future. One of these is the digital solid-state circu it breaker. Circuit breakers manage the flow of electricity and serve as a critical safety feature, providing protection from faults in the electrical system. Despite the important role they play, circuit breakers have not kept pace with an increasingly digital world (Figure 1). Most breakers are analog devices that have not changed significantly since they were first introduced for mainstream use in the mid 20th century.
1. Circuit breakers have been mechanical switches for 140 years. Digital circuit breakers, as part of a digital circuit breaker electrical panel, can be combined with smart software and connectivity that could help remotely monitor and control energy use in homes and other buildings. Courtesy: Atom Power
In contrast, digital solid-state circuit breakers use semiconductors to control the flow of power and can be managed via software that allows the user to meter, monitor, and control their loads on a computer or mobile device. In May 2019, North Carolina-based Atom Power introduced the first digital solid-state circuit breaker to be listed by Underwriters Laboratories (UL). Its unique blend of semiconductors and software makes this circuit breaker the fastest in existence—30 to 100 times faster than most mechanical circuit breakers.
Benefits for Utilities
Utilities stand to benefit from the installation and use of digital solid-state circuit breakers when it comes to load-side management. Just recently, smart meter technology has allowed utilities to go beyond the substation, and monitor and control power in the neighborhoods themselves. Despite this advance, the technology is not very granular—readings are taken every 15 minutes and are for the whole home, and not what’s being used inside.
Digital solid-state circuit breakers (Figure 2) take the smart meter technology one step further by placing the meter at the edge of the grid (that is, the load center in the home) so utilities have access to information including what devices are being used, where they are located, how they are being used, and at what time of day. Collectively, this information can be used to construct a detailed analysis of how power is being used within the neighborhood at a household level, and help utilities manage variability and make decisions that lessen the burden on the power grid.
2. Atom Power’s 20A (left) and 40A (right) solid-state digital circuit breakers for the residential market fit into 80% of existing homes, according to the company. A 100% digital breaker provides easy demand response, distributed energy routing, and has built-in Wi-Fi capability. Courtesy: Atom Power
A good example is managing coincidental loads. Running too many high-electricity-consumption loads at once can strain the power system, potentially leading to outages. If an entire neighborhood had digital circuit breakers connected to its water heaters, for example, the utility could monitor when and for how long each water heater is turned on. The utility would be able to see when spikes in demand occur (such as between 7 a.m. and 8 a.m. when people shower before work), and could tailor when breakers are turned on and off throughout the day to save power.
The utility also could use this information to inform homeowners and encourage them to spread out their use of high-load devices. By “flattening the curve” when it comes to power usage, the utility can maximize its use of existing capacity and minimize overburdening the power grid.
Benefits to Homeowners
Digital solid-state circuit breakers offer several benefits to homeowners. Once a digital circuit breaker is installed, there’s no need to rewire a home’s power system or install multiple panels and breakers to accommodate DERs. The homeowner can view loads and sources, and control power use from anywhere, at any time, using a mobile device. The ability to remotely manage power allows homeowners to make changes in real time based on their current needs. This process helps maximize energy efficiency, reduce wasted power, and save money through utility-sponsored programs.
Another benefit is the technology’s facilitation of demand management and metering. Via an app interface, the homeowner can view metrics such as amps, volts, and power consumption, and turn devices on and off. Over time, the app builds a profile of the homeowner’s power use—what devices are they using on a daily basis, for how long, and where is that power coming from and going? The app can even tell if there’s extreme weather (such as a hurricane or ice storm) or a wildfire close by so the homeowner can charge their battery, car, phone, and other devices to have as much power in reserve as possible.
Electrification of everything is key to a clean energy future. Maximizing the use of available energy will be critical to realize a clean energy future. DERs are an essential part of this transition. Yet, in order to usher in more DERs, the technology must be there to make a homeowner’s life better than it was before.
It will not be an easy transition. Recent blackouts in California and Texas highlighted major vulnerabilities in the current power grid and showed how much work still needs to be done. Meanwhile, EV adoption will have a significant impact on the capacity of the power grid. As barriers to EV adoption continue to fall away, more consumers will invest with greater frequency and this rising adoption presents another challenge—and opportunity—for utility providers. Creating a strong DER network is essential to support a reliable, efficient, and sustainable power grid.
To pave the way for DERs and a clean grid, smart, efficient solutions will be needed to enable a smooth transition to electrification. Digital circuit breakers could be one answer; with their ability to simplify power systems and demand response through remote control, they are easier and faster to scale and customize than traditional mechanical circuit breakers. Digital circuit breakers might be the technology needed to advance the integration of DERs into the power generation landscape, accelerating the adoption of EVs by making EV charging more cost-effective, safer, and easier to scale, and by facilitating the integration of multiple DERs in the home.
—Mike Harris is the chief technology officer for Atom Power.