Why Does the Power Go Out When It’s Cold?
By Erich Gunther
The extreme cold temperatures experienced by a large part of the United States this month have highlighted the vulnerability of power systems equipment in such extreme weather. This week’s snowstorm led to power outages in the Northeast, but cold weather alone can be enough to cause problems: The Tennessee Valley Authority, which serves 9 million people in the Southeast, urged customers Thursday to conserve energy to prevent a cold-weather outage. The average person might ask, why would my power go out when it’s just cold outside?
The electric system consists of thousands of components that are mostly electromechanical, with lots of moving parts. Like your car, these systems work best when they operate in the middle of the temperature and moisture/humidity range they were designed for. When they are new, these devices are designed and rated to operate correctly in even extreme temperatures. But as they age—and much of our infrastructure is already operating well beyond the life span for which it was designed—they may not operate well in extreme conditions. (See related quiz: “What You Don’t Know About Electricity.”)