Cute-Weather-elements-vector-02Running a university campus is akin to operating a small city with its own utility. I already had some sense of this fact, but it was really driven home for me when I had a long conversation over coffee with someone who spent 30 years in Utilities and Energy Management on UT-Austin’s main campus. For a college campus, it’s all about energy and water use, and the drive toward maximum efficiency. Here’s a summary of what I learned in that coffee conversation.

The Basics
UT-Austin’s physical plant is an electric utility. The campus operates a combined-cycle, natural gas plant with several turbines. The process begins with steam. Natural gas-fired boilers turn liquid water to steam that is used for two purposes: 1.) turning turbines that make electricity, and 2.) for heating applications. The steam in the turbines is extremely hot and high pressure, but after it leaves the electricity-generating turbines, it’s still useful for heating purposes. The steam and electricity from the physical plant reach the other campus facilities through a labyrinth of tunnels. Like other college campuses, UT has miles of utility tunnels where water, electricity and steam flow. Even beyond the physical plant water and energy remain closely linked. For one thing, electricity is required to power pumps and fans that move air and water within the buildings.

One thing I found surprising was that heating is needed for the buildings even on triple-digit summer days! The building cooling systems chill air to around 55 ºF to sufficiently remove moisture, so steam is used to raise that temperature to a more comfortable 70-ish degrees. This 55-degree air means that to conserve energy they sometimes let indoor temperatures drop! It’s always advisable to carry a sweater when you visit UT.

UT-Austin’s main campus has made great stride in efficiency over the last 30 years. Though the campus has nearly doubled its indoor square-footage, natural gas and water use has dropped below 1980 levels. They achieved these impressive gains in efficiency largely through utility upgrades. Over years, the physical plant has been over-hauled and configured for combined heating and power operations with high-efficiency turbines. They now can find and prevent resource waste through individual metering/monitoring of steam electricity and chilled water for all buildings, or building sections. An elaborate system of water recovery collects lab equipment cooling water, rainwater and condensates for reuse on campus. All these efforts plus high standards for new building projects have pushed water consumption down from one billion gallons/year (1980) to around than 700 million and natural gas down to about 1970′s usage.

Various initiatives through the campus’s Energy & Water Conservation Program have also spurred efficiency efforts. For example, the Longhorn Lights Out campaign encourages everyone on campus to turn off lights and office equipment. These efforts have reduced the campus electrical load by hundreds of kilowatts.

Solar Potential
Located in one of the sunniest places on the planet with millions of square feet of rooftop, the UT main campus has huge potential for solar energy. It’s a matter of working out the technical details. So far the campus has incorporated solar on a relatively small scale. They have solar photovoltaic (PV) installations with a total capacity of around 500 kW. However, average electrical demand is around 70 MW. Also, one building (NHB at 24th and Speedway) utilizes solar thermal for water heating.

The big question is how to incorporate solar photovoltaics (PV) into UT’s campus utility operations. PV presents a number of challenges, including coordinating the solar energy availability with natural gas turbine operations and electrical demand fluctuations. Currently, the turbines are fairly well-optimized to meet variations in demand by running certain combinations of their multiple turbines at/near maximum output for maximum efficiency. The variability of sunshine would simply have to be built into optimizing utility operations. That may be easier said than done, yet quite possible.

On the energy and water conservation front, UT-Austin’s main campus has made great progress. But, of course, the university is committed to doing even more. The next big goal is 20% reduction in water and energy by 2020 (FY 2009 baseline). Given the campus’s track record, I wouldn’t be surprised if they surpass that goal.