Facilities Info Center

Most people know that many buildings at Princeton are heated with steam produced in the University's Energy Plant. A multitude of underground pipelines deliver that steam to various dorms and academic buildings. Some of those buildings have different requirements as to the type of steam they need. Some need high-pressure steam, some need low pressure steam. The Energy Plant produces high pressure steam which was converted locally as needed to low-pressure steam by means of a special pressure-reducing valve. The problem was, considerable energy was lost as the steam pressure was reduced.

The Engineering Department (part of Princeton University Facilities) realized that there might be a way to recover some of that energy as electricity. “I first saw a "micro-steam" power generating system at a trade conference,” said Energy Plant Manager Ted Borer. “The opportunities for large campuses that have existing steam pressure reduction points were immediately evident.”

Essentially a small steam turbine driving an electrical generator, these self-contained power systems replace the pressure reducing valves at key points. After the high pressure steam is used to generate electricity, it is exhausted from the system at a much lower pressure - perfect for use in the University's low-pressure heating system. The two small turbines in the basement of Dillon Gym produce enough electricity to power several dorms. "The electricity is not 'free,'" said, Mr. Borer, "but it is very inexpensive and it really helps to reduce the University's carbon footprint."

The two units in Dillon are projected to generate between three and four million kWh of electricity annually while helping the University realize a key part of its sustainability plan. “Many of the most impactful efforts in energy conservation and sustainability happen behind the scenes with little fanfare or community awareness,” said Sustainability Manager Shana Weber. “This small turbine project is a terrific example.”