"Across North America, hundreds of downtowns, college campuses and hospitals are heated by steam carried through networks of underground pipes. Electric companies installed many of these "steam loops" or district energy systems more than 100 years ago in older East Coast cities like New York, Boston, and Philadelphia.

Today, these systems, which often provide chilled water for cooling as well, are experiencing a renaissance as a potential solution to climate change.

In Philadelphia, the steam gets generated at a red brick plant built in 1915, one of the few remaining industrial sites that sits along the Schuylkill River. Steam travels through 41 miles of pipe to dozens of buildings, including the Philadelphia Museum of Art, the University of Pennsylvania and the newly built Comcast Towers.

"It's like a ring of steam where you have a bunch of people connected to that ring taking the steam and using it," said Mike Ancona, operations manager for Vicinity Energy, which owns and operates Philadelphia's steam loop system."

Susan Phillips reports for NPR October 7, 2022. [2]