Dr. Evan Mills, an energy policy analyst at the Lawrence Berkeley National Laboratory has published a study of the carbon footprint of marijuana growing operations. The report, "Energy up in Smoke: The Carbon Footprint of Indoor Cannabis Production" (pdf), analyzes energy use and carbon emissions based on standard equipment and practices.
Specific energy uses include high-intensity lighting, dehumidification to remove water vapor, space heating during non-illuminated periods and drying, irrigation water preheating, generation of CO2 by burning fossil fuel, and ventilation and air-conditioning to remove waste heat. Substantial energy inefficiencies arise from air cleaning, noise and odor suppression, and inefficient electric generators used to avoid conspicuous utility bills.
Based on extrapolation from a standard 4' x 4' module, Mills estimates total US indoor Cannabis production to have a large carbon footprint. (As with any average computation, individual results will vary.)
Power use scales to about 20 TWh/year nationally (including off-grid production and power theft), equivalent to that of 2 million average U.S. homes. This corresponds to 1% of national electricity consumption or 2% of that in households—or the output of 7 large electric power plants.
So why should you care about energy consumption and carbon emissions associated with Cannabis farming? Well, energy and climate issues tend to be wonky and dull. So let's have some fun.
You want to grow your Cannabis ethically and in an earth-friendly manner? Well, for starters, you need to lose the diesel or gasoline powered generators. I know they help keep your on-grid electricity use down, but those generators are a buzzkill for Mother Earth. Here is why.
Off-grid diesel- and gasoline-fueled electric generators have emissions burdens that are three- and four-times those of average grid electricity in California. It requires 70 gallons of diesel fuel to produce one indoor Cannabis plant, or 140 gallons with smaller, less-efficient gasoline generators.
Mother Earth has given you a gift with those buds. It is not cool to give her a headache because you want to push the limits of production. Just say no to generators.
Where you grow matters. If you live in a state with a large renewable energy portfolio, then your carbon footprint will be proportionally lower from your on-grid use. If your state burns mostly coal, then so are you. Do yourself and the planet a favor. Get involved in politics and push for more clean renewable energy generation. In the long run, high carbon fuels like coal and natural gas are going to be ridiculously expensive. That means less green for your green in the future.
Make sure you use the most energy efficient grow lights, ventilation equipment, and hydrology you can find. Be ruthless in your efficiency of your growing operation and your living space. It matters. Efficiency is also the key to keeping a lower profile on the grid and keeping your costs lower.
Cost-effective efficiency improvements of 75% are conceivable, which would yield energy savings of about $25,000/year for a generic 10-module operation.
Mills does not recommend that you try to run your growing operation on solar power. However, he misses an opportunity to encourage adoption of solar systems for heating your water. Likewise, skip the fancy car if you are doing well. Instead, invest the money in geothermal wells if appropriate for your area. Those systems can take your heating and cooling off the grid and radically reduce your carbon footprint.
Also, lose the gas-guzzling vehicle to get your product to market. A Prius or Volt can hold a lot of product.
Mills says the ideal way to grow Cannabis without high energy cost and high carbon footprint is to take your operations outdoors. Unfortunately, in many areas, that will attract unwelcome attention from the eyes in the sky. This is why decriminalization is so important. If you can convince the politicians to register and tax growers, they could balance their budgets and you could do more with natural sunlight. Mother Earth will love you for it.
In fact, many argue that criminalization is an important driver towards energy-intensive indoor production. Criminalization also contributes to many of the energy inefficiencies in the process, including long driving distances, noise and odor suppression measures that undercut ventilation efficiencies, and off-grid power production that is far less efficient produces more greenhouse-gas emissions than many electric grids. Moreover, decades of criminalization has resulted in this energy-using sector being passed over by massive efforts to incentivize and mandate efficiency improvements.
Just remember. The best buzz comes with a tiny carbon footprint. The planet you help save by growing more with less energy just might be your own.
And for the rest of us, this is an issue where criminalization of marijuana contributes to worst possible energy practices. Unfortunately, continued aggressive prosecution shows no sign of abatement at the federal level.
For the record, Dr. Mills is a contributor to the Intergovernmental Panel on Climate Change (IPCC). I suspect that explains the carpet-bombing of comments by climate zombies in the coverage of Mills' report in the mainstream media. The comments attached to this piece in the San Francisco Business Times has 15 pages of zombie crap. Even the biggest and hairiest bud on earth cannot make these fossil fools tolerable.
Energy up in Smoke: The Carbon Footprint of Indoor Cannabis Production
Read the full report
Read the executive summary
Visit Evan Mills website