LEILA FADEL, HOST:
Across North America, hundreds of downtowns, colleges and hospitals are heated by steam carried through underground pipes. Susan Phillips of member station WHYY in Philadelphia reports these steam lube systems could be a climate change solution.
SUSAN PHILLIPS, BYLINE: The steam that travels through 41 miles of pipe below Philadelphia's streets is generated at a red brick building built in 1915. Officially known as district energy systems, most of us notice this underground network only when residual steam escapes from the sidewalk grates.
MIKE ANCONA: It's like a ring of steam where you have a bunch of people who are connected to that ring or are taking their steam and they're using it.
PHILLIPS: Mike Ancona is the operations manager with Vicinity Energy, which owns and operates Philadelphia's steam loop system. The plant illustrates the evolution of electric generation. High-arched ceilings are lined with tiles, and detailed brickwork points to an era when electricity had begun to replace guest lighting in earnest.
ANCONA: When this place was built, like, a hundred years ago - right? - these boilers ran on coal. There would have been a 60,000-ton coal pile sitting here.
PHILLIPS: The days of coal-generated steam are long gone. During World War II, the plant switched to oil. Today, modern natural gas boilers generate electricity sold to the grid. The waste heat makes the steam. Ancona says this highly efficient and flexible system could easily ditch natural gas and replace it with renewable energy or lower carbon fuel to generate that steam. In fact, Vicinity Energy has begun to do that with the steam loop system it owns in Boston, says CEO Bill DiCroce.
BILL DICROCE: And the building owners don't have to do a thing; so no major retrofits, no big capital expense on their part, no disruption. We become the easy way to decarbonize huge swaths of building space in urban cores.
PHILLIPS: And it's not just cities that can benefit. Dozens of colleges have district energy systems in place where the fuel source is getting switched in order to lower a university's carbon footprint. But in Philadelphia, two federal agencies plan to switch from Vicinity Energy's district steam system to natural gas boilers; this despite President Biden's commitment to tackling climate change and his executive order mandating federal agencies work to limit emissions. These include Amtrak's big train station and buildings operated by the National Park Service, like the historic Independence Hall and the Liberty Bell Center. This angers environmental groups that support the steam loop system because of how easy it would be to use it to cut the city's overall carbon emissions. Joseph Ingrao is an attorney who worked with the Clean Air Council.
JOSEPH INGRAO: The federal government has pledged over $14 million to installing these natural gas boilers that can only burn natural gas for heat.
PHILLIPS: An Amtrak spokesperson says the new gas boilers will be cheaper and more reliable. The National Park Service says switching to natural gas will cut its carbon emissions. But that could not be independently verified. Vicinity's DiCroce says the environment should be taken into consideration.
DICROCE: Those who decide to lean towards the cheapest alternative will make different decisions with those who are trying to look forward to a less carbon-intensive future. And they'll be willing to pay a little bit more for the advantage of being better for the planet.
PHILLIPS: Supporters of district energy systems say it's not just a lower carbon climate solution. They also are more resilient in the face of extreme weather. After Superstorm Sandy hit the East Coast in 2012, district energy systems remained online.
For NPR News, I'm Susan Phillips in Philadelphia. Transcript provided by NPR, Copyright NPR.