As Washington's experiment in legalization of recreational marijuana use moves gradually toward full implementation, the consequences for Washington's utilities are begining to come into focus. Confirming more general studies we've discussed previously, the Northwest Power & Conservation Council ("NPCC") this week will be discussing a staff report that quantifies the range of increases in electric consumption that may arise from marijuana legalization in Washington, as well as other Northwest states that may follow Washington's lead.
Consistent with other studies, the NPCC study recognizes that, although indoor marijuana cultivation offers a number of advantages to the grower, it is extremely energy intensive. This fact is dramatically illustrated by comparing the energy intensity of indoor marijuana production with the energy intensity of aluminum production, perhaps the most energy-intensive of the Northwest's traditional industries. Aluminum production, the study notes, requires roughly 16 kWh of electricity to produce one kilogram of aluminum, while indoor grow operations require a whopping 4,000-6,000 kWh to produce one kilogram of marijuana. All told, the NPCC estimates, marijuana legalization in Washington will produce an increase in electricity consumption in the range of 60 to 160 average MW over the next two decades, while demand will grow approximately 240 aMW in the four-state region by 2035. In addition, the study notes, the demand from grow operations varies significantly over the course of the day, and a proliferation of grow operations may therefore add to utility peak-hour demands.