Sustainability capstone class reports on current and future campus energy use

May 6, 2014 | by Jill Sakai

The first offering of the Sustainability in Practice capstone class culminated in student presentations of research on campus energy use on April 30.

The course, taught by Angela Pakes Ahlman, is a project-based course that provides an experiential team learning experience dealing with sustainability issues related to campus operations. In spring 2014, one student team worked with the Energy Center of Wisconsin on a project to model the impact of climate variability on campus energy use. The other team worked with University Housing to evaluate phantom energy loads in residence halls to better understand how behavior influences energy consumption.

The first team, composed of seniors Colleen Borchard and Sara Nelson and foreign exchange student Santiago Bisso Urrutigoity, estimated how much energy the UW–Madison campus will consume under the projected climate conditions of 50 years in the future. Based on correlations between monthly average temperatures and current monthly average energy consumption, they calculated average energy use under the warmer temperatures projected by future climate models.

Overall, the students found that annual energy consumption would decrease, largely due to reduced winter heating needs that were not completely offset by increased summer cooling needs. Since the model does not account for monthly or hourly variability, however, they said it is hard to know how temperature extremes, which are projected to increase with climate change, will affect actual energy demands and whether current peak capacities will be sufficient under future conditions.

The team also used building models to calculate energy use and performance measures in Agricultural Hall and Van Hise Hall. They reported that the variables with the largest impacts on building energy use, such as heating efficiency, were generally not modifiable, but that they were able to identify smaller factors such as improving window and door seals that could be implemented.

The results surprised the group. “We thought climate change would have huge impacts and that we would be able to make changes that would make a big difference,” said Borchard during the presentation. “It was interesting to learn that things are often more complex that you imagine.”

The second team, comprised of seniors Sarah Solberg, Allison Strauss, and Ben Williams, conducted a study to determine the magnitude of phantom load – that is, electricity consumed by appliances that are not being used such as phone chargers and TVs in standby mode – in UW–Madison residence halls.

The students measured the energy draw of various electronics in student rooms in Witte, Chadbourne, and Tripp Halls and used a model from the Energy Center of Wisconsin to determine what percentage of total electric plug load was accounted for by phantom energy use. They calculated that phantom load accounts for 5.5 percent of total electricity used in the residence halls.

From conversations with residents, the capstone students also learned that few students knew what phantom load was or how to reduce it. As a follow-up to their project, they recommend educating students to unplug appliances – especially phone or computer chargers and any electronics with standby lights – when not in use to save energy and money.

“We determined that phantom load costs University Housing about $50,000 every year,” said Strauss. “Turning off an appliance really has a big impact.”

The course will be offered in future years as ES 602 and will serve as the capstone course for the newly approved undergraduate Sustainability Certificate.