Extremists “adhering to a range of ideologies will likely continue to plot and encourage physical attacks against electrical infrastructure,” the report warned.
More than 6,400 power plants and 450,000 miles of transmission lines run across the country.
After the two electrical substations in Moore County, North Carolina, were shot up, thousands of utility customers had no power for several days. At the height of the outage, more than 45,000 customers were left in the dark amid freezing temperatures.
“It was targeted; it wasn’t random," said Moore County Sheriff Ronnie Fields at a news conference Sunday.
It was the latest of a number threats to the power grid over the last decade.
In 2013, the Federal Energy Regulatory Commission ordered grid operators to increase security following a sniper attack on a
California power substation. The case remains unsolved but caused power outages and millions of people were advised to conserve energy.
A
Utah man was arrested in 2016 and was later sentenced to federal prison after he used a rifle to shoot the cooling fins on a substation, which caused the substation to overheat and fail. The man had planned to attack other substations to take down power in portions of the western United States, court documents said.