Go Green; Grow Outside: The Risks of Unregulated Energy Use in Indoor Cannabis Production

By Chester Harper

Cannabis is quickly becoming a global phenomenon. Despite some backwards slides in recent years, it is difficult to argue against the inexorable shift towards recognizing cannabis as a legitimate recreational and medical substance. Today, 10 U.S. States and District of Columbia have legalized recreational cannabis use. Thirty-four states and the District of Columbia allow some form of medical cannabis use. Every one of these states is violating federal law, and yet they persist because science, public opinion, and economics are all on their side. Internationally too, Canada and Uruguay are poised to create the first national recreational cannabis markets. And this is a great thing.

For decades, legal scholars, civil rights activists, and legislators have questioned the policy of cannabis prohibition. The astronomical cost of waging the War on Drugs, the cruel and unequal impact on minority populations, and the complete absence of scientific evidence that cannabis should be a controlled substance in the first place are well-documented facts. These considerations aside, however, naked economics are a major driving force behind the push for legalization.

In the year after legalization, the Cannabis industry in Colorado generated 18,000 new, full-time jobs. California, Colorado, Washington State, and Oregon collectively have seen $6,087,600,000 in revenues since legalizing recreational sales. Globally, the legal cannabis industry (already valued at $9.2 billion) is predicted to grow by over 500% by 2027. Again, this is a great thing.

Yet, in this headlong rush into a new, exciting, and profitable industry, we need to be cautious that we do not create new problems while fixing old ones. As with any industry, cannabis production is not free from environmental externalities. Cultivating the thirsty cannabis plant has already caused sever reductions of surface-water levels in some western states. A lack of research and regulatory action by the EPA has also created confusion and public scares about proper pesticide use with cannabis crops. This issue that poses the greatest long-term threat, however, is energy usage.

Generally speaking, most cannabis cultivated in the U.S. today is produced indoors under grow lights. In addition to high-energy lights running 12-18 hours a day, these facilities also require heating and cooling equipment, humidity controls, and ventilations systems, all of which use prodigious amounts of electricity. One study estimates that an indoor production facility capable of producing 1 pound of product per grow cycle will use approximately 13,000 kW/h per year. Based on this figure, the same study estimated that the total amount of energy used in cannabis production in the U.S. in 2012 was around 20TW/h. This is the energy consumption of 2 million average American homes, equals the yearly CO2 emissions of 3 million average American cars, and accounts for around 1% of total U.S. energy use for that year. Moreover, this figure can only have exponentially increased during the intervening years, and the cannabis industry could quickly become a major contributor to global CO2 emissions in the very-near future.

Many States, out of an overabundance of caution (and perhaps the puritanical view that seeing drugs is enough to lead one to vice), require indoor production for safety reasons. That aside, indoor production appeals to cultivators on its own because of higher yields and quality, year-round cultivation, greater control of the product, and as a secondary method of pest control.

It is critical for regulators to consider the long-term environmental impact of the cannabis industry looking forward. Efficiency standards for grow operations are the obvious first step. So would be a renewable energy mandate, such as requiring grow operations to put up a certain number of solar panels to offset energy generated with fossil fuels. But, the simplest solution might be aggressively encouraging cultivators to grow their products outdoors. Cannabis is, at the end of the day, an agricultural commodity. Indoor production is more of an artifact of decades of anti-cannabis policies than a result of market factors. Indoor production will have its place in the cannabis economy of the future, but the current emphasis on indoor production is creating an energy use problem that doesn’t need to exist in the first place. The best and easiest way for the cannabis industry to go green is just to grow outside.

About the Author

Chester Harper is a 2L at Vermont Law School studying constitutional law, cannabis law, and legal writing and education, particularly legal history and academia.