Writer: Julie M. Hughes, 575-646-1953, firstname.lastname@example.org
Cost and energy saving strategies implemented this fiscal year at New Mexico State University have proved to be successful and will result in a balanced utilities budget for the university, said Rich MacRorie, director of facilities operations.
budget shortfall caused by rising energy costs was a challenge for NMSU's colleges and departments who struggled to make up the deficit, but many proactive efforts have alleviated that concern this fiscal year, MacRorie said.
The largest energy-saving measure taken was to negotiate a "time of use" rate for power with El Paso Electric Co.
"This type of contract establishes two rates for power consumed," said Rick Lobato, assistant director for engineering at NMSU's facilities operations. "The peak rate from 10 a.m. to 8 p.m. is about twice as much as the off-peak rate, but by running large energy-consuming equipment during off-peak hours we are able to maximize savings."
NMSU has a three-million-gallon thermal storage tank that stores chilled water for use throughout campus during the day. By using the storage tank, NMSU is able to chill water at night when the utility rates are lower. This avoids the need for an additional electric chiller. The university is using an automated control system to provide cooling to controlled buildings during the occupied portion of the day, while conserving energy during non-occupied times.
"In addition to the energy savings that these setbacks generate, the reduction of the chilled water demand on campus provides the university with the opportunity to recharge the thermal storage tank," Lobato said.
The university also runs its three domestic water wells at night, filling a four-million-gallon reservoir to use throughout the day.
"We strive for optimal energy use at the Central Utility Plant, which in some cases can mean hourly evaluation and selection of equipment to run in order to continue to provide utilities on campus at the most reasonable cost available," Lobato said. "This new rate system coupled with other energy savings strategies has resulted in substantial cost avoidance at NMSU."
NMSU also owns a 4.9-megawatt co-generation unit fired by natural gas that produces one-third of the electricity the university needs during its peak hours. This unit is equipped with a heat recovery steam generator which takes the waste heat and converts it to steam. This steam can then be used as thermal energy including sometimes running two 1,500-ton absorption chiller units to provide 3,000 tons of cooling to campus.
The university is striving to install meters in all of the large campus buildings allowing facilities to monitor utility consumption and follow up on any unusual consumption patterns.
"Monitoring the meters gives us the opportunity to investigate and make repairs to problems that otherwise might go unnoticed," Lobato said.
NMSU also partners with the city of Las Cruces to "collar" gas prices when it will benefit both parties. This type of contract specifies a set price for a given quantity of natural gas during a specified period of time.
"This type of contract is not without risk in that there are penalties if we do not take a specified minimum amount of natural gas for that period, not to mention the risk that the market price of gas could drop lower than the negotiated rate, but both NMSU and the city have been very fortunate the past couple of years and have managed to save on utility costs using this system," Lobato said.
MacRorie and Lobato serve on a university Energy Task Force that has been meeting for almost two years. The group's first task was to decide how to equitably divide the energy deficit among the university's colleges and departments, but now it has turned its attention to conservation.
© 2013 New Mexico State University Board of Regents
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