Freezer Challenge encourages energy-saving practices

Here’s a little-known fact: A single ultra-low temperature lab freezer uses about as much energy as an entire house. As a top-tier research university, Carolina operates thousands of these across campus.

There’s a movement afoot, led by a San Diego-based nonprofit called My Green Lab, to increase the energy efficiency of lab equipment. Since 2017, My Green Lab has held an annual competition called the International Laboratory Freezer Challenge. It should come as no surprise that here at Carolina — home of many athletic championships and even a string of flu vaccination titles — research teams competing in the Freezer Challenge are in it to win it.

(My Green Labs)

Leading the pack is the lab of Patricia Basta, a clinical assistant professor of epidemiology at the Gillings School of Global Public Health. Basta’s biospecimen repository is a “core lab,” which means it serves other labs on campus as well. Her lab has 15 freezers that use a lot of energy.

In 2021, Basta’s lab was one of 12 recipients of the International Laboratory Freezer Challenge’s Lab Award, winning in the category of “biorepository/core facility/shared cold storage award.”

This year two Carolina labs participated in the national challenge: the lab of School of Medicine professor Xian Chen, which saved 29.35 kWh per day, and the Basta Lab, which saved 135.7 kWh per day. As the best performing UNC-Chapel Hill lab in the challenge, Basta’s team won $5,000 towards the maintenance or purchase of an energy-efficient ultra-low freezer.

The overall winner in the academic sector this year was the University of Virginia.

UNC BioSpecimen Processing Facility director Patricia Basta (shown here with Kimon Divaris) in the Michael Hooker Research Center. (Jon Gardiner/UNC-Chapel Hill)

Why energy-efficient freezers are important

Switching to an energy-efficient freezer may seem like a small change, but it can have a significant impact on the environment.

This year, over 1,200 labs from 120 research institutions participated in the Freezer Challenge, saving a collective 9.5 million kWh of electricity. That is the equivalent of reducing carbon emissions by about 6,700 metric tons — or about the same amount produced by 1,450 gasoline-powered vehicles in a year.

“It’s astounding how much energy is used by laboratories in general,” Basta said, “but also freezers in particular.”

Basta said that she and her lab are motivated to do this work because “we want our children and our grandchildren to have a place to grow up.”

Purchasing energy-efficient freezers at Carolina is made easier by the Renewable Energy Special Projects Committee, a student group funded through a green energy fee students pay for renewable energy infrastructure, energy efficiency and energy education. RESPC offers rebates of 35% of the cost of an ultra-low freezer — around $5,000 — which is roughly the difference between an energy-efficient model and a standard freezer. RESPC also offers the prize for the best performing Carolina lab in the My Green Lab Freezer Challenge.

Over the last few years the Basta Lab replaced its 15 freezers purchased in 2004 with energy-efficient models that RESPC and its campus partners approved. Basta said she is very appreciative and supportive of the RESPC program. Without it, they may not have been able to replace the older units at such a quick pace.

How labs conserve energy

In addition to buying energy-efficient appliances, there are other ways labs can save energy.

The Freezer Challenge takes into consideration whether labs vacuum freezer coils and air intakes, if they defrost their freezers, if they clean out old samples that are no longer needed and how efficiently they store their samples.

Since 2020, the Basta Lab has discarded enough old samples to clear two entire freezers.

Biological samples from one of the Basta Lab’s freezers. (Jon Gardiner/UNC-Chapel Hill)

Basta urges other labs to vacuum freezer filters, check gasket seals every couple of months and generally be more aware of their lab’s footprint.

Basta’s lab also shares equipment, a practice that has been gaining traction at Carolina. There is a clinical researcher LISTSERV where labs can list equipment and supplies they want to share or don’t need anymore. As the medical school labs have the most funding, they are often replacing equipment. With the LISTSERV, they can donate the older equipment to other labs. (Send an email uncgreenlabs@unc.edu to join.)

In addition to being green, being mindful of experimental design and processing flow to prevent wasteful use of supplies like gloves and pipette tips helps their lab with budgeting and supply chain issues, Basta said.

“We never compromise our samples,” she said, “but we try to do our work in such a way that we can minimize the number of [supplies] we use.”

The green-lab movement at Carolina

A group of faculty, staff and students at Carolina called UNC Green Labs encourages sustainable practices and promotes awareness of green issues in the University’s laboratories.

Last year, the group began printing stickers to indicate what equipment can be turned off when.

“Just like any part of the University, there is a transient population — a lot of students in and out, researchers in and out — and you say turn off the equipment, but people don’t know what’s OK to turn off and what’s not. They don’t want to mess it up for somebody else,” said Cindy Shea, Sustainable Carolina’s sustainability director and the adviser for RESPC. “So we printed up stickers that say, ‘Turn me off when not in use,’ ‘Turn me off at the end of the day,’ ‘Don’t ever turn me off.’”

UNC Green Lab’s initiatives are being adopted campuswide. The effort involves lab managers and researchers as well as support organizations like Sustainable Carolina; the office of waste reduction and recycling; energy management; and environment, health and safety. This includes promoting greener practices, including the Freezer Challenge.

Shea said that Basta and her lab are setting an example for other labs to follow.

“The Basta Lab has been really taking this to heart,” Shea said. “It’s a value of theirs. The staff see the merits of doing things more sustainably, thereby reducing environmental impact, reducing the risk to their samples and saving money for the University.”

Lab workers are busy with their work and securing grants, Shea says, so many are unaware of the full scope of resources available to them.

“We want the labs that are involved in science — super important efforts, over a billion dollars of sponsored research annually, life-saving strategies — to adopt a culture of sustainability,” Shea said. “And in order for anyone to do that, you need to provide them with the tools to make it easier.”

Carolina has developed a certification program based on what other schools around the country are doing, encouraging labs on campus to adopt the same sustainable practices. Most of the actions are easy to implement, such as putting up posters that clarify what is recyclable, maintaining an inventory of lab samples and shutting the sash on fume hoods when they are not in use. Clear guidelines on when to use tap water instead of distilled water and dishwashers instead of autoclaves are also important.

Basta said that she and her lab have learned a lot of green techniques from both the international My Green Lab Freezer Challenge and Carolina’s own initiatives.

When she first started at Carolina, recycling wasn’t readily available. Now, recycling bins are abundant and most of the plastics used in the lab are recycled.

“UNC has really made strides,” Basta said.