Prisma Photonics, Houston, in partnership with Great River Energy, installed a grid-monitoring system across 90 miles in northern Minnesota, according to a January 2025 press release. This state-of-the-art PrismaPower technology will enable real-time monitoring and notification of threats to transmission lines, such as wildfires, icing, wind and physical damage, including downed lines.

Having this information could protect against blackout threats, which increase during the same conditions that produce severe weather. According to Climate Central, there were 64% more “major power outages” from 2011 to 2021 compared with 2000 to 2010, and more storms are expected in the coming years. 

PrismaCircuit and PrismaClimate solutions will be implemented across five critical transmission lines connected to four substations through fiber optic lines in central and northern Minnesota in a multiyear deal.

“As we work to maintain reliable service for our member-owners throughout Minnesota's distinct seasons, we’re leveraging innovative new technologies that maximize our existing infrastructure investments,” said Priti Patel, vice president and chief transmission officer with Great River Energy, a nonprofit power cooperative that serves 1.7 million people in Minnesota and Wisconsin.

The new technology relies on existing optical fiber infrastructure instead of needing installation of physical sensors on power lines, as is common with traditional monitoring solutions. This eliminates service interruption.

According to the company’s website, “The Interrogator transmits optical pulses that propagate down the fiber. A minute fraction of the light is reflected from each point along the fiber. The Interrogator measures the reflected light to determine the strain, temperature, pressure, and other quantities,”

Likened to “tens of thousands of microphones,” the system sends high-quality data to computers that use machine learning and algorithms to determine threats, provide reliable alerts and filter out false-positives and other needless alarms. 

Real-time alerts are generated for grid events such as electrical faults, physical disturbances and severe weather conditions. The alerts pinpoint the precise location all the way to the specific tower, allowing maintenance crews to respond more quickly, reducing downtime and improving grid reliability.

Prisma Photonics CEO Eran Inbar says this advanced technology will enhance grid resilience without the complexity and maintenance requirements of traditional sensor-based solutions.

Great River is also testing other new technology, such as Norway-based Heimdall Power’s “magic balls,” sphere-shaped sensors deployed on cables to collect data, maximize capacity and possibly enable more renewable energy use.

“As the world grapples with increasing extreme weather events, innovative power utilities like Great River Energy are working to adapt by hardening and modernizing grid assets to ensure safe, continued service for customers,” Inbar said in the January release.