Electric transmission planners with the Eastern Interconnection, a major power grid serving two-thirds of the United States and Canada, recently gave a favorable review in their assessment of how well regional plans mesh to maintain systemwide reliability. 

However, the planners, known as the Eastern Interconnection Planning Collaborative (EIPC), added a cautionary note.

EIPC’s Zach Smith, executive committee chairman, said planners concluded that “the Eastern Interconnection remains strong, and that individual and collective transmission planning activities have yielded a system that is reliable and well-coordinated on both a regional and interconnection-wide basis.”

Smith issued a word of warning, though.

“Nevertheless, looking forward, the grid is being...