Electricity usage for indoor grows is off the charts
Now before you roll your eyes, kick back, and light up: Researchers have estimated that indoor grow operations account for a whopping 1 percent of total electricity use in the United States each year. (Indoor grows can be attractive because they offer multiple harvests and shorter grow times.)
“Whopping 1 percent” might sound a little paradoxical, but think about how crazy that number is. That’s about the same amount of electricity consumed by every computer in every home and apartment in the country annually.
Why’s that number so big? It mostly has to do with the high-intensity light bulbs that pot plants need to thrive when grown indoors.
In order to power all those light fixtures, as well as dehumidifiers and heating and ventilation systems, indoor grow operations use about eight times the amount of energy per square foot as a normal commercial building. That’s on par with a modern data center.
When indoor operations are run illegally, they’re even more energy intensive, because growers will often use diesel or gasoline generators to avoid pulling power from the grid and being detected. All told, indoor production is one of the most energy-intensive industries out there.
That’s also the amount of carbon sequestered by 1.6 acres of U.S. forests in a year.
Which is a problem, because we’re also cutting down trees for outdoor growing operations. Speaking of which …
Growing outdoors isn’t perfect either
While growing pot outdoors is naturally more energy-efficient than doing so indoors — after all, you don’t need to plug in the sun — free-range weed has a different kind of environmental impact. Getting a patch of land ready for farming can mean cutting down forests, diverting rivers, and destabilizing whole ecosystems.
Pesticides and rat poison can also kill animals around outdoor grows. Consider the Pacific fisher, a cat-sized weasel-like character. A recent study suggested that more than 85 percent of Pacific fishers near grow sites in the Sierra Nevada range were exposed to poison, which accounted for about 10 percent of all deaths of the threatened species.
Though you can solve some of these problems by moving your operation into a greenhouse, that will still require electricity for ventilation, temperature and humidity control, and supplementary high-intensity lights.
Pot plants are thirsty
In a sizable outdoor operation, the plants can suck up something on the order of a billion liters of water per square mile over a growing season. Some estimates suggest that pot plants use six gallons of water per day per plant over the summer. For reference, it takes about four gallons of water to run an energy-efficient dishwasher once.
So try thinking about your weedprint in terms of pizza
Here’s how we can put this data in terms of your own smoking and munching habits. That pizza sitting between you and those Aqua Teen Hunger Force reruns has a hefty environmental footprint, too. (Cows can eat a whole hell of a lot of alfalfa, and alfalfa is a thirsty plant.) To get a sense of pot versus ‘za, use our nifty calculator to compare a joint to a pizza slice: