Smoke on This: Marijuana Growers Use One Percent of U.S. Electricity Supply

Hey, hippies! Next time you light up that spliff filled with kind bud, consider this mind blower: One percent of U.S. electricity consumption -- or the output of seven large electric power plants -- is dedicated to growing marijuana indoors each year, according to a recent report. The upshot? Getting stoned on high-end specialty strains of weed commonly sold at medical marijuana dispensaries affects more than your wallet and appetite. Now there's the environment to think about as well.

Granted, the indoor pot growing industry doesn't have the same carbon footprint as say, petroleum refiners. But the impact isn't negligible, either. About $5 billion worth of energy is used to grow weed, which generates 17 million metric tons of carbon dioxide. That's equivalent to 3 million average American cars, according to the report.

As any pot farmer can tell you, it takes a huge amount of electricity to grow weed indoors. High utility bills are the bane of many a paranoid grower. Evan Mills, the Lawrence Berkeley National Labs analyst who authored the report, found the energy demands for pot are bigger than even marijuana mavens realized. Pot grown indoors requires lighting levels that match those found in hospital operating rooms. It also needs 30 hourly air changes, 60 times the rate in a modern home. That electricity intensity is on par with modern data centers.

Greening the weed business
Pot growers would enjoy huge financial benefits by becoming more energy efficient. Any improvements within the field are likely to be scattered, at best. Pot growers are a highly disjointed and secretive bunch. It's difficult to create a national energy-efficiency movement when you don't know who to reach out to. The industry doesn't have to adhere to any state or federal energy efficiency standards either. (Go figure.)

Energy efficiency is a question that states, especially ones like California with high electricity demand and a burgeoning indoor growing industry, may be forced to contend with eventually. To date, 17 states allow people to grow pot for medical purposes. And many more are considering passing similar laws.

For those folks who think renewable energy is the answer: think again. According to Mills, installing solar panels at the growing operation site doesn't make sense:

Using solar to power inefficient systems is a waste. A costly, mega-sized solar system to run a bunch of inefficient lights, fans, and chillers in a single house would just give solar a bad name. For the same investment, many dozens of conventional houses could be made highly energy efficient and then be solar-powered all the way to zero carbon emissions. This would provide much more carbon-bang for the buck.

• Smoking a joint is equivalent to keeping a 100-watt light bulb on for 17 hours.;
• Growing one kilo of weed is equivalent to driving across the country 5 times in a 44-mile per gallon car.
• One single production module (4x4x8-foot chamber) doubles the electricity use of an average U.S. home and triples that of an average California home. A single grow house can have 10 or more such modules.

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