Sensors Help Create a Greener Grid


Electric co-ops are using electronics and analytics to welcome renewable energy

To actually see the green power revolution, look up at the power lines. If you spot a little box about the size of a tennis shoe clamped onto one of the wires, you’re looking at something that’s bringing in a whole new era in energy.

Sensors, like the Aclara power sensor shown here, measure voltage, current ,and additional data that’s important to electric utilities. Sensors are installed on overhead electrical equipment, like power lines and transformers. Photo Source: Aclara

It’s called a sensor, a container of electronics that collects and sends out information about the wire it’s on, from the voltage inside to the temperature on the outside. Sensors are starting to appear all over the nation’s electric grid—that’s the term for the nation’s network of power plants and substations connected with millions of miles of power lines. These sensors are also being used with other electrical equipment, like electric meters and transformers—those cylindrical containers you see on top of utility poles.

Sensors are one of many technologies that are enabling changes in the way the electric grid is planned and operated, like the rapid growth in renewable energy, says Venkat Banunarayanan, senior director of integrated grid technologies for the National Rural Electric Cooperative Association (NRECA).

Managing Wind and Solar Power

“The grid is going through a lot of changes,” says Banunarayanan. “It’s changing the way we create, transmit, and use electricity.”

The U.S. electric utility network is moving from one that used to ship out a mostly steady stream of electricity from large coal or nuclear power plants to a more dynamic, decentralized system where power moves back and forth, off and on. Rooftop solar owners can sell excess electricity back to the utility along the same wires that bring power into their home. A wind farm that powers a utility might suddenly quit generating when the wind dies down.
How does the electric grid manage all that? Part of the secret is in the sensors, says Banunarayanan.

“You install those sensors at different points on the grid and you can get an accurate picture of how the grid is performing,” he says. “The more sensors and real-time information you can get back to the grid operators, the better they can identify and address any problems.”

Just a few years ago, electric utilities could plan their power plant production around one peak time of energy use a day—like 6 p.m., when people came home from work and school, and started to turn on lights, cook dinner, and watch TV. Large power plants ran nonstop to keep the electricity flowing.

Sensors, like the Aclara power sensor shown here, allow electric utilities to quickly and cost-effectively gain better situational awareness of grid conditions. Unlike more traditional methods for monitoring grid conditions, which require utilities to do extensive planning and turn off power while work is done, power sensors are installed without disrupting operations. Photo Source: Aclara

Renewable energy changes how utilities need to plan around people’s schedules. Wind and solar power used to not matter so much—10 years ago, they only generated 3 percent of our electricity. Today, that’s up to 8 percent and growing fast. The on-again, off-again nature of wind and solar means your electric co-op needs to be ready to switch among power sources instantly. There are also safety issues—utility workers need to know when rooftop solar panels are feeding electricity back onto power lines. These changes mean that electric utilities need to look at grid performance and plan accordingly––throughout every hour of the day and night––instead of just looking at the peak time of energy use in a day.

Plugging in Electric Vehicles

Electric vehicles are also bringing changes. Banunarayanan notes that every major car company is planning to increase production of electric vehicles, including large and small commercial trucks.
What happens at night when all those semi-trucks pull into a warehouse or a rest stop along the interstate and plug in?

“There are infrastructure, business model, and communications issues,” says Banunarayanan. “What are the ways in which the infrastructure needs to be strengthened for commercial trucks to be electrified … even for sedans and other electric passenger vehicles, what are the implications in a residential subdivision if everyone plugs in at the same time to charge their vehicles?” Alternatives to infrastructure strengthening could include providing incentives for charging during “off-peak” periods––during mid-day or the middle of the night, and educating consumer-members on the most economical electric vehicle charging periods.

In addition to installing more sensors, creating a greener grid could call for upgraded power lines. Besides electric vehicle charging stations, solar and wind power will have to be transmitted from the plains and deserts where it’s generated, to the communities where it’s used. One industry estimate predicts the utility industry will need to spend 20 to 50 percent more through the year 2030 to upgrade the grid, and 50 to 170 percent more from 2030 to 2050.

While more power lines and more sensors are keys to greening the grid, Banunarayanan says another essential ingredient is professionals who know how to use all the information sent in through the hardware and software.
“Data scientists or data analysts, who help create decision-quality insights from data––these are some of the hottest jobs right now,” he says. “Utilities are applying these techniques to the data that we get from the sensors to create quality insights and actionable decision making.”

For all its cyber-age sophistication, Banunarayanan sees the greener grid as just another stage in the development of electric utilities.

“The grid is changing; however, the basic function of the grid is not,” he says. “The grid exists to supply cost-
effective, reliable, and safe power. It’s just changing to give consumers more options.”

Paul Wesslund writes on consumer and cooperative affairs for the National Rural Electric Cooperative Association, the national trade association representing more than 900 local electric cooperatives. From growing suburbs to remote farming communities, electric co-ops serve as engines of economic development for 42 million Americans across 56 percent of the nation’s landscape.