Growing marijuana indoors may be worse for the environment than previously thought, according to one researcher.
In a study, Evan Mills of the University of California at Berkeley and researcher at the U.S. Department of Energy, measured the production costs and outcomes of cultivating this cash crop indoors. The project was not funded by either organization, he writes.
Even though nearly one third of indoor growing occurs in California, the findings expand to other known producers throughout the United States with permits to supply medical marijuana to licensed dispensers.
The primary culprit? High-intensity ultraviolet (UV) ray lamps that provide light to marijuana plants. These light sources produce some 500 times more light than what’s necessary for reading. In addition, they’re often left on for 30 or more hours on average, according to the study.
Considering other factors such as ventilation and watering, a standard room to grow the plant uses roughly 13,000 kilowatt hours per year, with some homes containing 10 such rooms for growing cannabis.
In total, Mills concludes, the energy used to grow marijuana indoors accounts for 1 percent of the nation’s electricity consumption and 2 percent of household electricity use — comparable to the “output of 7 large electric power plants.”
Typically, one kilowatt hour provides enough energy to power a small fridge for 24 hours or give you four evenings of light with a 60-watt incandescent lamp, according to a TreeHugger.com article. This interactive webpage helps give you an idea of how much energy other household appliances use.
As highlighted in a Greenwire/New York Times article on the analysis, indoor cannabis cultivation produces the equivalent of three million cars on the road in greenhouse emissions each year. These gases are known to trap heat in Earth’s atmosphere and contribute to global warming.
“The added electricity use is equivalent to running about 30 refrigerators,” Mills writes in the paper, referring to the added costs of indoor growing per home. “Processed cannabis results in 3,000 times its weight in (carbon dioxide) emissions.”
Mills writes he does not have an agenda in studying the practice. Rather, he thinks the cost effectiveness of indoor pot production has rarely received attention and can be easily improved to save growers money and alleviate negative effects on the environment.
At present, 17 states as well as the District of Columbia have active medical marijuana programs, according to the National Organization for the Reform of Marijuana Laws.
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