Massive heat pump and underground loop planned for Seattle University energy pilot

Puget Sound Energy is seeking master use and construction permit approvals to build an innovative $18.5 million Thermal Energy Network pilot at Seattle University. Designed as a model for urban district heating and cooling, the project is hoped to demonstrate the technical and commercial viability of shared thermal loops that recycle waste heat between buildings and could cut load on an increasingly stressed Seattle energy grid.

The core of the project in planning along the school’s multilevel Broadway parking garage is a high-efficiency, 4-pipe hydronic loop powered by an industrial air-source ammonia heat pump capable of delivering 3,000 MBH of heating at 180°F and 285 tons of cooling at 40°F, according to plans posted by PSE with the city.

By linking multiple campus facilities including Lemieux Library, Campion Hall, Loyola Building, and the Student Center through specialized Energy Transfer Stations, the system would replace fossil-fuel boilers with centralized, electrified thermal transfer. Two 2,000 MBH natural gas boilers would also be installed for emergency backup.

The project would include new above-ground utility plant structures on the southwest corner of the campus. Engineering plans call for two modular, shipping-container-sized central plant buildings located in the alleyway just east of the university parking garage. One module will house the heat pump compressors, hydronic distribution pumps, heat exchangers, and electrical controls, while the second enclosure will hold the backup boilers and loop-distribution equipment. Industrial condensing units will be permanently installed across the upper deck of the adjacent parking structure.

Getting the required construction signoffs requires multi-agency coordination across city departments. Records show the construction permit application remains under review following a completed preliminary land-use assessment. Because the project requires approximately 1,500 feet of pipe trenching that extends into public rights-of-way along Broadway and E Columbia, the Seattle Department of Construction and Inspections must wait on Street Improvement Plan approvals from the Seattle Department of Transportation before issuing building permits. City reviewers have established requirements to preserve mature street trees, implement stormwater controls, and maintain traffic around streetcar tracks and protected bike lanes. Seattle City Light must also finalize underground electrical designs and verify mandatory safety buffer zones around overhead high-voltage lines before groundbreaking can occur.

Just up Broadway, a similar vision has faced steeper funding hurdles. CHS reported in 2022 on Seattle Central College’s early efforts to replace its aging steam heating system by pursuing a private partnership to build an on-campus, fossil-fuel-free central power plant and “EcoDistrict.” Progress on that plan has remained uncertain as the college’s broader proposal for a new six-story Information Technology Education Center on Broadway stalled. By 2024, Seattle Central estimated its project would cost $22 million and require a mix of local funds, state contributions, and outside financing. While SCC had secured about $2 million in grants (including a $700,000 federal grant via Seattle City Light), college leadership recommended postponing the major funding push to the 2027–2029 state budget cycle.

Seattle Central, meanwhile, has a different vision for its major parking structure. The school’s long-term plan calls for the Harvard at Pine parking facility to someday make way for affordable housing.

The Seattle University pilot reflects a broader national and global shift toward district energy systems that transition fossil-fuel infrastructure into shared, electrified heating and cooling loops.

In Seattle, projects like Amazon’s campus recycle data-center waste heat through underground hydronic pipes, while the University of Washington is pursuing the $50 million conversion of its historic central steam plant into a low-temperature hot-water network.

Across the country, regulated utilities are increasingly exploring thermal networks as a core decarbonization strategy: Eversource recently launched the nation’s first utility-run neighborhood geothermal network in Framingham, Massachusetts, and major New York utilities are deploying dozens of state-mandated pilots linking universities, commercial sites, and residential communities.

District networks are already standard in cities like Vancouver, British Columbia, which heats neighborhoods via municipal sewer heat recovery, and across Scandinavia, where vast urban centers rely on ambient industrial loops and large-scale heat pumps rather than fossil combustion.

The transitions have long timelines putting any significant residential transition to district energy in Seattle on track for sometime in the next two decades as networks come online and the city’s aging gas mains reach end-of-life or coincide with city street, sewer, and water replacement cycles.

For now, there is also not a planned timeline for flipping on the switch at Seattle U.

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