Understanding Campus Energy Consumption - People, Buildings and Technology

Colleges and universities in the U.S. spend an average of $1.10 per square foot (ft(2)) on electricity and 18c/ft(2) on natural gas annually. In a typical college or university classroom building, lighting represents 31 percent and space heating accounts for 28 percent of total energy use, making those systems the best targets for energy savings [1]. This study utilizes five years of data enlisting a campus as a test bed to understand the interactions of people, buildings and technology on energy consumption and to explore how to reduce peak energy use to reduce costs and benefit the community. The University of Texas at San Antonio (UTSA) has 150 buildings on 850 acres at the main campus and 4 buildings on 18.4 acres at its downtown campus. Five years of energy consumption data has been analyzed using 15-minute interval data accessible from 1 main meter and 2 sub-meters, as well as building information and weather data from a weather station immediately adjacent to the downtown campus. The baseline analyses shows that the maximum campus energy demand occurs on weekdays during the day, followed by no-class holidays and weekends. The demand is minimum during UTSA holidays when there are fewer staff and faculty/students present on campus. The study showed there was a linear correlation between temperature and energy consumption for the downtown campus, however for the Durango building where the solar panels have been installed, this correlation was negative. Solar panels that have been deployed on the Durango building to help minimize the load during the day, when the electricity consumption is highest. The annual peak consumption occurs during summer, which is expected due to the south Texas climate. The energy utilization intensity (EUI) data for the downtown campus shows that UTSA has continually lowered the EUI since 2010, although the EUIs remain higher than ASHRAE standard requirements.