Aug. 26, 2009

What makes the ISU power plant special

by Diana Pounds

Most universities produce their own heating and cooling, but buy electricity elsewhere. Iowa State is among a few universities that heat, cool and generate electricity. The process, known as cogeneration, is more efficient because the steam that turns a turbine to make electricity can be partially recovered and used to heat buildings and generate chilled water for cooling.

The efficiency of Iowa State's power plant drops as the need for electricity overwhelms the cogenerating opportunities. Today, only 20 percent of the electricity used on campus can be cogenerated.

The other 80 percent, whether generated by the ISU power plant or purchased from outside sources, is more costly than cogenerated electricity. ISU officials anticipate wind-generated electricity from NextEra will be less expensive than power that is not produced by the cogeneration process. The wind-generated electricity will be competitive with power purchased from outside sources during peak times of the day. For a quick look at the ISU power plant, see coal-fired efficiency.