Combined Heat and Power Plant

The medical school operates a combined heat and power co-generation plant that produces all of the steam and chilled water used by the heating and cooling systems on campus. The plant also generates nearly 90 percent of the electricity used on campus. (A connection to the regional electric grid is maintained for peak periods and as a back-up source of power.)

Originally built in the 1970s, the plant has been expanded and upgraded several times. Most recently in 2012, the plant was expanded and renovated to accommodate a high-efficiency, 7.5-megawatt combustion turbine and heat recovery steam generator, along with new emissions and control systems.

A variation of a jet engine, the new turbine is fueled by natural gas and spins a shaft attached to a generator to produce electricity. At the other end of the turbine, exhaust flowing at 960 degrees is funneled into a heat recovery steam generator to produce steam. Reusing this "waste heat" to make steam raises the efficiency of the plant and is the core of the "co-generation" configuration.

Steam produced by that system does triple duty: it powers two of the plant’s other turbo-generators making additional electricity, then moves through the steam distribution network to heat buildings and drive compressors that chill water to 42 degrees.

The 2012 expansion increased the plant’s electrical generating capacity to 17.5 megawatts. Simultaneously, because the plant now uses primarily natural gas, with oil only as a back-up fuel, its greenhouse gas emissions have been reduced.

Green fact: generating electricity on campus saves up to 30-percent of the fuel that would have been used by a distant power plant. This occurs because power is lost when transported great distances, so more must be generated to compensate for those line-losses.