Pot Growers Inhale 1% of U.S. Electricity, Exhale GHGs of 3M Cars

Indoor marijuana cultivation consumes enough electricity to power 2 million average-sized U.S. homes, which corresponds to about 1 percent of national power consumption, according to a study by a staff scientist at the Lawrence Berkeley National Laboratory.

Researcher Evan Mills' study notes that cannabis production has largely shifted indoors, especially in California, where medical marijuana growers use high-intensity lights usually reserved for operating rooms that are 500 times more powerful that a standard reading lamp.

The resulting price tag is about $5 billion in annual electricity costs, said Mills, who conducted and published the research independently from the Berkeley lab. The resulting contribution to greenhouse gas emissions equals about 3 million cars on the road, he said.

Narrowing the implications even further reveals some staggering numbers. Mills said a single marijuana cigarette represents 2 pounds of CO2 emissions, an amount equal to running a 100-watt light bulb for 17 hours.

"The added electricity use [to an average home] is equivalent to running about 30 refrigerators," Mills wrote. "Processed cannabis results in 3,000 times its weight in CO2 emissions. For off-grid production, it requires 70 gallons of diesel fuel to produce one indoor cannabis plant, or 140 gallons with smaller, less-efficient gasoline generators." (read more)