Energy Club recently installed occupancy and light data loggers in the bathrooms of Boliou, Davis and Nourse to audit light usage, funded jointly by the Environmental Advisory Committee (EAC) and the Sustainability Office. The information is being collected as part of a larger project to install occupancy sensors with funding from the Sustainability Revolving Fund (SRF).

Occupancy sensors turn lights on or off depending on whether an area is occupied. Several campus locations such as Watson Hall and the Complex dorms are already equipped with these sensors as a result of past Energy Club projects. The new data loggers, on the other hand, simply record when a light is on or off and whether a room is occupied.

The overall project was spurred by a visit from Xcel Energy, Carleton’s energy provider, during which auditors listed potential projects that could save the campus both money and energy. Among these was the installation of occupancy sensors in various buildings, with Bolious, Davis and Nourse named as target areas.

“Occupation sensor projects have also been done in the past, so we knew it was viable for the club,” explained club Co-president Kyra Ngai ’21.

The club then decided to gather information using data loggers to quantify the need for and potential benefits of occupancy sensors before proposing the project to the SRF, which requires that projects reduce Carleton’s greenhouse gas emissions in addition to saving money.

“These findings can help us determine how frequently lights are used in different rooms, and can bolster our proposal with solid data about how much money and energy the occupancy sensors could save,” said Co-president Sarah Allaben ’21.The club applied for funding for the data loggers from the EAC and unanimously received a grant of $1,025. The Sustainability Office covered the remainder of the cost, allowing Energy Club to purchase 10 HOBO Extended Memory Occupancy/Light Data Loggers—at $242 each—along with accessories for the loggers.

“We tried to express in the proposal how this purchase could both help with the enactment of many energy-saving projects on campus, and be a good way for students (particularly in Energy Club) to gain experience with a device commonly used in the sustainability and energy workforce,” said Allaben.

EAC Chair and Manager of Campus Sustainability Martha Larson was enthusiastic about the project, noting, “I really liked this project for how well-defined it is and how much the Energy Club members can learn from the experience of taking a project like this start-to-finish.”

“This work also supports and enhances our existing energy conservation initiatives, which helps build momentum on something that is already a stated goal of Carleton’s sustainability efforts,” she continued. “We rarely have time to sub-meter at the room level—all of our meters are at the building level. So this gives us very granular information about how effective certain energy conservation measures might be.”Two loggers have been installed in Boliou, with another two in Davis and six in Nourse. While Xcel recommended a variety of campus locations to target, Energy Club decided to start small with bathrooms.

“They are relatively small and have little, if any, ambient lighting. This makes them fairly simple when logging occupancy and light use. We figured this would be a good way to test out our new sensors and help us become more familiar with the tools,” said Allaben.

For now, the loggers are attached to the inside of the bathroom doors and are not expected to noticeably affect Carleton students or faculty using the facilities.

“They’re quite small and discreet so they shouldn’t be an obstacle for students, nor would they have a significant impact on behavior,” said Ngai. After two weeks, the data loggers will be removed and Energy Club will consider the data as they plan their proposal for occupancy sensors. The loggers themselves will become property of the Sustainability Office for future Carleton or Northfield use, though projects beyond the current one have not been planned.

“One of the EAC’s primary stipulations in approving the funds was that these loggers have a life well beyond this project,” said Larson.

In the future, energy Club hopes that the data logging methods developed through this project can be expanded throughout campus.

“This is a pilot project, so the end goal would be to expand the scope of it to other buildings on campus so that we can develop a more comprehensive profile of Carleton’s energy scene,” said Ngai.