We may take it for granted, but the electrical grid is one of the most remarkable systems around, sending electricity through thousands of miles of power lines into millions of homes and charging up billions of devices. Traditionally, it’s also been a centralized system, where the hub of a power plant pushes out energy into the spokes toward every end user. Climate change means that has to change, though — and in ways you may not expect.
“With renewables, the power goes bidirectionally, because consumers can also generate electricity,” says Dr. Mital Kanabar, global chief applications architect for GE Grid Automation. Literally millions of American households send electricity into the grid through net metering programs, a term for selling the extra electricity they don’t use from rooftop solar panels, home geothermal systems, electric vehicles and backyard wind turbines.
This basic shift in the flow of power means utilities have an urgent need to improve how they manage power lines. For one, decentralized renewable energy means utilities need to regulate the flow of power from all directions — power plant and net metering — to keep electricity from overwhelming line capacity and damaging grid equipment along the way.
There’s also a public safety issue: Imagine a fallen power line that cuts off a group of homes from the main power line. The utility can cut the power they send out to the line, but net metering customers beyond the point of line failure are still sending power out — which means the fallen line can still be live, posing a safety threat to people nearby. Unless a utility maintenance crew is on-site inspecting the line, they may not know net metering power is still pulsing through the system.
Among the solutions hitting the market is a new technology developed by GE Renewable Energy’s Grid Solutions division. “Checking grid conditions 500 times in every second, our system can identify the break in a live wire and, within a few hundred milliseconds, trip power to the wire,” Kanabar says. “That’s approximately 10 times faster than it takes for a broken wire to hit the ground.”
The new technology is available in a product GE calls the 850R Universal Recloser/Switch Controller. The intelligent controller is a high-speed industrial computer that continually monitors trouble by collecting and analyzing reams of data from digital sensors on the grid. It is the brain of a system that includes a recloser — a type of circuit breaker — that can switch electrical current on or off with multiple operations to restore reliable power. These are hung on power poles throughout a utility’s territory. The 850R can order immediate steps, such as shutting off electrical current, to mitigate risk if the data indicates an abnormality typically associated with distribution of safe, reliable and green electricity.
Used throughout a network of power lines, the recloser controllers essentially turn utility poles into intelligent watchtowers, identifying and addressing problems as they occur as well as instantly relaying their findings to the grid’s operators and maintenance workers. This approach is often called edge intelligence, because it pushes out monitoring from central utility control rooms or substations to geographically distant areas. These distributed controllers securely exchange information over wireless radio and respond to grid conditions. The recloser system also reduces the need for a crew in a truck to drive through the streets of a large city like a police patrol, making sure utility equipment is working. Instead, utilities can monitor grid health from a laptop and send workers to the selected hot spots.
Recloser controllers also offer built-in security protocols and can help rapidly isolate the effects of cyberattacks. They can quickly reroute electricity around the problem, so that important customers like hospitals, which require uninterrupted power, can keep their lights on.
Just a few years ago, Kanabar says, the idea of a digital distribution grid that could quickly respond to line failures and provide flexibility for variable green power sources seemed a goal attainable only far in the future. Today, he says, it will be one of the hottest topics of conversation at DISTRIBUTECH International, the leading annual electricity transmission and distribution event happening this week in San Antonio, Texas.
“Having electricity is a basic need these days,” Kanabar says. “Edge intelligence provides systems to help renewable integration into the grid, ensuring that the power is safe, green and available.”