Indoor marijuana cultivation is surprisingly energy-intensive – production facilities use about 10 times more energy than an office building per square foot.
It’s not just the lighting used to help plants grow, even though that accounts for between 30% and 40% of energy consumption. The greatest energy consumption, which often represents between 50% and 60% of the demand, is cooling and dehumidification to prevent sensitive cannabis plants from developing mold.
The high energy demand for dehumidification can cause the energy costs of marijuana grow operations to skyrocket, even requiring costly and time-consuming upgrades to electrical infrastructure. That’s why some growers are turning to an innovative, cost-effective alternative technology: propane or gas-powered chillers.
What is a gas cooler?
Gas chillers are actually a form of combined heat and power, or cogeneration, says Steve Lafaille, vice president of business development at Waltham, Mass.-based power generation company Tecogen, manufacturer of the Tecochill gas cooler. The system uses a propane or gasoline engine to drive the compressor through a cooling machine to create chilled water, while waste heat from the engine is recovered to create hot water.
Powering these energy-guzzling coolers with more affordable propane or natural gas instead of electricity can cut utility costs by 50 percent, Lafaille says. Perhaps just as importantly, these systems can help growers quickly and cost-effectively upgrade industrial buildings for growing marijuana when existing electrical infrastructure is insufficient.
Such was the case of a marijuana grower in Douglas, Massachusetts, who converted an old husk factory into a more lucrative cannabis cultivation facility. Like many older buildings, the old factory was electrically limited and at the mercy of the electric utility to upgrade. But producers don’t have time to wait.
“These people had 18 months, 24 months, 36 months to upgrade the power,” Lafaille says. “If you look at what is happening in cannabis, in three years the price is going to be halved in the market. So time is money in business.
Instead, the Douglas producer brought in a Tecochill unit that eliminates the need for additional electricity from the utility. With natural gas lines eight miles away, the facility used the existing 30,000 gallon propane tank to power the unit.
Gas cooling has applications in other agricultural and commercial markets. Lettuce, leafy greens and herb growers also use these systems, although their plants are less dependent on dehumidification. But he predicts the technology will play a bigger role in facilities that use process cooling all the time, like food and beverage manufacturers. “We’ve really proven that the product can operate 24/7/365 and has a very high degree of uptime and reliability,” says Lafaille. “And that’s what those other process cooling customers really want to see.”
Visit propane.com to learn more about how facilities improve resiliency and reduce their carbon footprint with gas cooling.