Hyper-greenhouse facilities

Hyper-greenhouses use 8-times as much electricity per square foot for lighting alone as the average U.S. office building uses for all purposes and 17-times as much as the average U.S. home.

To put this in another perspective, lighting-related CO₂ emissions are 1200-times the final product’s weight, or about 3 pounds of CO₂ emissions per “joint”.

And, given that yields are lower in greenhouses than in windowless warehouse grows, the energy use per unit weight of finished product is only 25% lower than that of windowless grows.

As the worrisome carbon footprint of indoor cannabis cultivation becomes evident, it is understandable hope springs eternal that greenhouses will save the day. Unfortunately, when implemented as high-tech, yield-maximizing industrial operations rather than as the kind of greenhouses grandma grew her tomatoes in or one that someone like Elon Musk might design, this strategy compounds our collective climate-change problem. This is an inconvenient truth for indoor cannabis. The market’s invisible hand isn’t solving the problem, and ham-handed policies forcing cultivation indoors are making it worse. Better practices can turn this tide.

See white paper for a discussion of alternatives.

Useful background materials:

• Technical paper by Larry Kinney on best-practices for greenhouse design.

• Presentations at the Cannabis Sustainability Symposium, Denver, 2017 (video)

Industrial hyper-greenhouse technology, with intensive electric and fossil-fuel energy inputs. (Source: Adaptive Plastics)

Note lights on during day. Each fixture ~1000 watts.

Net-zero greenhouse concept. (Source: Kinney et al., 2012)

Pure greenhouse technology, with no external energy inputs, maximizing the use of solar resources while adequately controlling environmental conditions to obtain large high-quality yields. (Source: CannaSol Farms)