From rooftop greenhouses to subterranean growth chambers, plant research facilities on the University of Toronto's historic St. George campus are quietly undergoing a major lighting retrofit - and gaining a research boost in the process.
The upgrade from fluorescent and incandescent lighting to energy-efficient LEDs is part of Project Leap, U of T's initiative to reduce greenhouse gas (GHG) emissions by more than 50 per cent at St. George by 2027. This includes replacing lighting in 38 buildings, saving enough electricity to power more than 520 homes annually.
In addition to helping U of T meet its climate goals - all three U of T campuses have pledged to become climate positive by 2050 - the lighting upgrades at St. George are unlocking new possibilities for the researchers who rely on these spaces for their work.
"Our growth chambers are finely controlled spaces where researchers can simulate different environmental conditions - from deserts to tropical rainforests," says Tom Gludovacz, chief Horticulturist.
"The lighting needs to be precise, consistent and tailored to the needs of the plants. Without this, you lose the reproducibility of experiments. Until now, this has been a real gap in our capabilities."
The 80 tightly controlled environmental chambers at St. George house more than 500 unique plant species, supporting research in areas ranging from evolutionary biology to plant resilience and insect migration.
Previously, researchers relied on a mix of fluorescent and incandescent lighting to simulate the full spectrum of natural light. But these older systems are inconsistent, energy intensive, difficult to source and contain toxic mercury - making them increasingly unsustainable.
With support from U of T Facilities & Services, Gludovacz and his team identified LED solutions that provide the right intensity and spectral quality for research-grade plant growth. The result is a complete retrofit of outdated lighting systems, replacing them with LEDs that use up to 80 per cent less energy and last up to eight times longer. The benefits: lower electricity demands, fewer repairs and less waste.
"These aren't your typical hallway or office LEDs," says Gludovacz. "They're designed for photosynthetically active radiation, the specific spectrum of light plants need."
The lighting upgrade is already making a difference.
Researchers in the departments of cell and systems biology and ecology and evolutionary biology (EEC) in the Faculty of Arts & Science, along with colleagues from a wide variety of associated disciplines, now have access to brighter, more consistent lighting, which is key to generating reproducible results and exploring new research avenues.
"One research group, led by [EEB] Professor Rowan Sage, is studying the evolution of photosynthesis using desert plants from South Africa, which thrive under intense light. That kind of experiment was much more challenging before," says Gludovacz. "We're planning high-light trials starting in July."
Another group, led by Micah Freedman, an assistant professor of ecology and evolutionary biology, is growing milkweed and analyzing its chemical signatures to track the migration of monarch butterflies across North and Central America. This work depends on precise growing conditions, which the new lighting now makes possible.
"We are grateful for the support of Project Leap in replacing the lights in our growth facilities," says Professor Nicholas Provart, chair of the department of cell and systems biology. "Not only will this help keep U of T at the top of the sustainability rankings , but it provides concrete benefits to our researchers with better light quality and reduced heat load for the plants we require for our research."
For Gludovacz and his colleagues, the lighting retrofit represents more than an equipment upgrade - it's a meaningful step in aligning campus infrastructure with the values of the research it supports.
"We've got faculty and students working every day on climate change, biodiversity loss, and sustainable ecosystems," he says. "It's rewarding to see the university making systemic changes that support that vision."
The growth chamber lighting retrofit is expected to save an estimated 500,000 kilowatt-hours of electricity per year, the equivalent of removing nearly 75 cars from the road. And because the new LEDs produce less heat, the chambers require less cooling, further reducing their energy footprint.
"By switching to energy-efficient LEDs across campus, we are reducing lighting-related energy use by 40 per cent," says Ron Saporta, chief operating officer, property services and sustainability. "Alongside work to connect our campus to the geoexchange under Front Campus , recover waste heat and switch from natural gas to electric heating systems, we are on track to become a climate positive campus by 2050."
