As the greenhouse sector continues to transition from legacy lighting to LED technology, one area remains largely unaddressed: the environmental and regulatory impact of the hardware being decommissioned. Brian Gandy, founder of Sustainable Terrains and the Relamp & Relax Program, has been working on LED retrofit projects in the horticultural sector and raises a critical point often missing from rebate-driven energy efficiency initiatives: end-of-life disposal of legacy high-pressure sodium (HPS) systems.
"I've done plenty of retrofits in the past. Nothing unusual about that," Brian says. "But what I uncovered along the way is something that too many rebate programs and LED upgrade consultants are still ignoring: what happens to the fixtures you take down?"
The issue centers not only on HPS lamps—already regulated for mercury content in jurisdictions like California—but on the ballasts embedded in older systems. Many of these fixtures, especially those manufactured before the adoption of digital ballasts, contain capacitors built with polychlorinated biphenyls (PCBs). PCBs are classified as persistent organic pollutants and banned in multiple countries due to their carcinogenic properties.
Brian cites a batch of 600W PL Light Systems fixtures from 1998 as an example. "Solid product. Durable. But inside those magnetic ballasts is a component that's often overlooked—the capacitor. In many older models, they were built with PCBs."
The financial implications for safe disposal are nontrivial. While standard e-waste might cost $0.30 to $0.50 per pound to dispose of, PCB-containing ballasts can cost $6 to $8 per pound. At 25 to 30 pounds per fixture, the true cost of responsible recycling can exceed $80 per unit—before accounting for lamp disposal, labor, packaging, and compliance documentation.
Brian continues: "So, while rebate providers are happy to tout the energy savings of LED retrofits, the actual environmental footprint of these upgrades tells a more complicated story. If we're pulling down toxic hardware and dumping it in a landfill under the guise of sustainability, we're not solving a problem—we're just shifting the burden downstream."
Many rebate programs currently in place do not account for the cost or logistics of removing and recycling legacy materials that may be classified as hazardous waste. Brian notes that in most cases, this side of the retrofit process is either passed on to growers or ignored entirely.
"Rebate facilitators often act as middlemen, eager to clip a profit from the rebate spread without truly engaging with the operational or environmental side of the retrofit," he says. "That's a problem."
According to Brian, addressing this requires involvement from power providers and utilities. "If you're writing the check for a retrofit, you should be writing one for recycling, too," he says. "The watt-for-watt savings look good on paper. But the real picture: the environmental impact, the toxic load, the compliance risk, that's what tells the truth."
Brians Relamp & Relax initiative works to build this reality into lighting transition programs by incorporating safe decommissioning and recycling into the project scope. "Every lamp recycled helps grow tomorrow's cultivation systems," he concludes. "Let's make sure we're not trading one invisible cost for another."
For growers and suppliers working on retrofit plans or involved in rebate processing, Brian advises contacting qualified partners to ensure materials are handled appropriately. "If you don't work with us, work with someone, but do the right thing and get lamps and e-waste to an appropriate recycling channel."
For more information:
Sustainable Terrains
Brian Gandy
brian@sustainableterrains.com
www.sustainableterrains.com