Energy and marijuana: inside out

Cannabis goes by a lot of nicknames—grass, weed, bud—that evoke the plant’s natural origins. And legalization advocates often argue that’s it’s absurd to criminalize a plant: Who in their right mind would put Mother Nature in handcuffs?

But step inside walls of today’s massive indoor-grow operations and rows of glaring lights, electric ventilation and irrigation systems—plus the high power bills paid to run them all—make indoor cannabis growing look less than natural.

A recent energy-use report authored by one California scientist and a Humboldt County-based group are taking a critical look at the carbon footprint of industrial-scale indoor-cannabis growing. Concerned about the environmental impacts as more entrepreneurs jump into the lucrative growing industry, they’re part of a budding movement urging cannabis consumers to start asking themselves: How green is my grass?

In April, energy and environmental systems analyst Evan Mills released his report “Energy Up in Smoke,” which examined the power usage and carbon footprint of indoor cannabis-growing operations. (While Mills is a staff scientist at the Lawrence Berkeley National Laboratory, his website emphasizes that the report was conducted independently and on his own time.)

Mills crunched the numbers for running high-intensity lighting, pumps, dehumidifiers, heating and irrigation systems, plus the electric gadgets that control them, and found that they come with high energy and carbon costs.

The report finds that nationwide “indoor Cannabis production results in energy expenditures of $5 billion each year, with electricity use equivalent to that of 2 million average U.S. homes,” with all related carbon dioxide production equaling that of 3 million cars.

In California, indoor growing is responsible for about 3 percent of all electricity use, or 8 percent of household use.

The report says a single indoor-cannabis cigarette represents 2 pounds of CO2 emissions; one indoor off-grid plant—like that in rural areas that require power from generators—requires 70 gallons of diesel fuel to produce.

Mills writes that cost-effective efficiency improvements of 75 percent are conceivable, and that “shifting cultivation outdoors eliminates most energy uses (aside from transport).”

In other words: To grow the greenest, most eco-conscious weed, outdoor is the way to go.

But Kris Burnett, owner of Kris’s Corner Organic Wellness Collective in Carmichael, points out that there are several hurdles to outdoor growing, especially in urban areas, such as crop security, exposure to law enforcement and the local pot regulation ordinances.

“Nobody knows what [Sacramento] County is planning to do,” said Burnett, who opened her collective in June. “It’s a gray area with the law.”

She also points to patients who live in assisted-living homes or apartments with no place to grow outdoors.

Burnett stocks only buds grown with natural nutrient sources such as bat guano; that decision stems from both her and her husband’s fight with cancer when she “replaced chemicals with organic medicine.”

She wryly points to another benefit to growing outdoors: not supporting PG&E. “They’re not out for the community,” she said.

Sacramento-area grower Andre Williams might appreciate that. Cultivating both indoor and outdoor cannabis over the last three years, he says power bills alone can easily run upward of $800 a month.

Of indoor growing, he said, “It uses up so much power. That in itself is not being very green.”

He’s tried making his indoor grows more energy-efficient, but the technology isn’t quite there. For example, when he tried LED lights, which suck a third of the energy of high-pressure sodium light fixtures, he found they didn’t penetrate below the canopy of the plant. “Everything beneath doesn’t get enough light,” he said.

While outdoor growing is less energy-intensive, indoor growing also gives him more control over the end result.

“Indoor is always going to be there because it creates a better quality product,” said Williams. “I can look at a bag [of cannabis] and know if it’s indoor or outdoor.”

Members of Grow It in the Sun, an organization of noncultivator advocates started out of Humboldt County, have been quietly educating patients, growers and dispensary owners about the environmental impacts of cannabis growing.

Grow It in the Sun’s Charley Custer told SN&R that his organization doesn’t speak out against patients who grow their own medication in their closets at home.

“What we’re trying to do is raise awareness of the destructive, and even insane, practices of industrial and commercial growers,” said Custer. “We have nothing to say against whatever practices individuals use to get their own medicine.”

Custer says that for the most part, he’s had successful conversations with people getting them to think about their weed.

“A great many have never thought about this before. A great many have never seen natural plants before,” he said. “A great many don’t think about where their cellophane-wrapped meat comes from before, either.”