Cogeneration unit
Cogeneration unit will supply heat and cooling to UNM main and north campuses.
Credit: Bruce Cherrin

The University of New Mexico Ford Utilities Center recently invested in a second cogeneration unit that will dramatically lower greenhouse gas emissions and bring economic stability to the utility infrastructure for years down the road.  According to Physical Plant Director Mary Vosevich, UNM will always be dependent on electrical generation, but with the completion of the new cogeneration unit, the university will be capable of generating 50 percent of its peak load. 

 “The cogeneration unit will provide steam and electricity, and the electricity production will be much greater than our current renewable energy systems, while also reducing more carbon footprint,” Vosevich said. “We operate the cogeneration units when it is most cost effective to do so.  This helps keep the operating costs within budget.  It also helps lower our carbon footprint since we use natural gas to operate our units.”

Jeff Zumwalt, associate director of the Physical Plant Department, said cogeneration is a term used for combining heat and power to maximize efficiency in a district energy system, and that cogeneration is the perfect fit with district energy. UNM generates its own utilities at the Ford Utilities Plant which supplies heating and cooling to the buildings on main and north campus. Zumwalt said the new cogeneration unit will help stabilize increasing rates from local utility providers, such as PNM.

“We can either buy electricity from PNM or we can make our own.  Cogeneration allows us to make our own electricity.  We make it with natural gas, and natural gas is at historical lows in regards to price. PNM rates for UNM have gone up 50 percent in the last five years. That spreading amount between PNM expenses and natural gas prices really makes it ideal for us to make our own electricity.”

Larry Schuster, university utilities engineer, has been working on major modifications to the district energy system since 1983.  He said the second cogeneration unit doubles the capacity UNM already generates, improving from six megawatts to 12 megawatts, and that cogeneration and district energy allows heating and cooling systems to be more reliable and energy efficient.  Schuster said if each building had its own heating and cooling equipment, it would be far less efficient than the combination of cogeneration and district energy. 

“When you take the old mechanical equipment in buildings and combine it with all the new equipment, the overall efficiency is higher in a district energy system than any particular unit,” Schuster said. “The fact that we can reclaim waste heat through cogeneration, and individual building equipment cannot, makes our system far more efficient.”

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