During an Illini Lights Out event, small groups of students are assigned buildings to audit on or near the main Quad to turn off non-essential lights in classrooms/bathrooms not in use. Conducting these light audits is a simple, fun and interactive way of engaging students with energy conservation while raising awareness of energy usage as it relates to climate change. Initiating a year-round light auditing program gets students involved in increasing energy efficiency and reducing building-level energy for the duration of the academic year. Energy, emissions, and dollars saved can easily be calculated using the data volunteers record.

A one-time initial pilot of Illini Lights Out was conducted by ECBS SWATeam members on April 15, 2016. A total of 1,533 lights were switched off during this event in 8 campus classroom buildings. In addition, volunteers closed 71 windows that had been left open. The SWATeam estimates that this one effort alone resulted in approximately $250-300 in energy savings for the campus. In 2016-17, the Student Sustainability Committee awarded funding for a year-long run of monthly Illini Lights Out events.

Illini Lights Out was relaunched for Fall 2021 after a hiatus due to the Covid-19 pandemic.