A Cottage Industry with High Electricity Use

Can growing marijuana change the way homes use electricity? In rural Humboldt County, in far-northern California, there’s no doubt that it can. Figure 1 tracks average monthly residential electricity use in Humboldt County and in California. Until the mid-1990s, these two values were almost identical. But after 1996, Humboldt County’s electricity use suddenly turned upward. What happened? In 1996, California voters passed Proposition 215, which legalized the medical use of marijuana. In practice, Proposition 215 enabled almost anyone to purchase marijuana. Humboldt County supplied much of the upsurge in demand. Marijuana is a hardy plant and grows just fine outdoors, but many farmers grow it indoors to protect themselves from nosy neighbors, police, and gangs. It’s a true cottage industry.

Two researchers at Humboldt State University, Peter Lehman and Peter Alstone, have documented the energy and environmental impacts of marijuana production in the region. Growing marijuana indoors is an electricity-intensive operation, relying on banks of grow lights and industrial-scale ventilation fans. Even a “modest” operation can rack up several thousand kWh per month. Hundreds, if not thousands, of Humboldt County residents supplement their incomes with “grows.” Similar enterprises exist throughout North America. In Colorado, for example, a single raid found grows in 25 Denver basements. The only difference is that in Humboldt County, the electricity impact is visible at a regional level.

Most energy auditors, utility repair staff, and weatherization crews can tell stories about visiting homes where the occupants are growing marijuana or running other drug operations. Sometimes the auditors never get beyond the front door, or perhaps they are told not to enter a certain room, or the “garage” out back. In any event, that’s usually a signal to abort the job and leave the premises.

It is also important to understand the consequences of growing marijuana inside the house. Simply put, cultivating marijuana indoors destroys homes. The plants create water vapor, which encourages highly toxic mold growth and destroys building materials. The larger operations abandon any pretense of living in the house, because they chop holes in walls and floors for ventilation and wiring. These are greenhouses masquerading as homes, and they are not habitable without tens of thousands of dollars of remediation. The police department of Ottawa, Canada, maintains a list of homes where marijuana is grown so that city authorities know which houses are likely to have mold and structural problems. Of course, the house might burn down before the mold does it in, if the huge electrical loads overwhelm the residential wiring, or stolen electricity is brought in the house through amateur wiring.

Without arguing the merits of legalizing marijuana, it is clear that our drug laws have created a new—and large—use of residential electricity. One likely side benefit of decriminalizing marijuana will be reduced home energy use in Humboldt County, in California, and in the rest of North America.

 

Figure 1. After 1996, Humboldt County’s per capita electricity use suddenly turned upward. What happened? (Image credit: California Energy Conservation, U.S. Census)

 

- Alan Meier