How Green is your Cannabis?

carbon footprint

How "Green" is Your Cannabis?

eGrid designations with legally purchased Cannabis Indica prop | © George H. Thomas

eGrid designations with legally purchased Cannabis Indica prop | © George H. Thomas

Legal Cannabis In Washington State

The legal Cannabis industry is highly regulated, taxed, transparent and is experiencing rapid growth. As of December 2016, Washington State has collected $374 million dollars in excise tax and $119 million dollars in state sales tax through $1.3 billion dollars of legal Cannabis since July of 2014.

In November 2012, with a nation-leading voter turnout of 81%, the citizens of Washington State approved Initiative 502. The Washington State Liquor Control Board (WSLCB) expanded its mission to govern I-502 and was renamed The Washington State Liquor and Cannabis Board (WSLCB).

I-502 creates a three-tier system for recreational cannabis production and sales.

  • Producers: specifically licensed by size of indoor or outdoor canopy of cannabis 
  • Processors: process cannabis flower into a trackable packaging system. Cannabis flower for smoking, oils, and extracts for vaping or infusing into edibles. Each package labeled with a documentation of potency, either a THC percentage or a measure of THC in Milligrams for edible consumption.
  • Retailers: sell to the public; age 21 or older, within a secure retail facility. 

Washington State Initiative 502 intends to:

  • Allow law enforcement to focus on violent and property crimes.
  • Generated new state and local taxes.
  • Shift the illicit cannabis market to a tightly regulated market that is similar to alcohol.



Plants grow by converting light energy to chemical energy using the process of photosynthesis. Photosynthesis occurs under natural sunlight as well as indoors with artificial light, powered by electricity. Indoor Cannabis cultivation can be very energy intensive.

With indoor cultivation, Metal Halide bulbs (MH) are used for vegetative growth and High-Pressure Sodium (HPS) that are tuned to the wavelength of a late summer sun, for flowering growth. The performance of light intensity is measured in lumens. Metal Halide and High-Pressure Sodium bulbs can run from 12 to 18 hours a day. Heating Ventilation Air Conditioning systems (HVAC) manage the resulting heat.

The low cost and higher resulting yield of Metal Halide and High-Pressure Sodium bulbs, when compared to Light Emitting Diode (LED) are currently the preference among many indoor cultivation operations. LED lighting is starting to close the gap in some specialized cultivation applications, by providing more power efficiency and reduced heat output. LED lighting can be tuned to numerous wavelengths as well, providing very precise controlled lighting. Alternatives to indoor cultivation include outdoor cultivation using sun energy or within a greenhouse with supplemental Metal Halide lamps.

Data Transcribed from EPA eGRID database | Chart © George H Thomas

Data Transcribed from EPA eGRID database | Chart © George H Thomas

The Carbon Footprint of indoor cannabis cultivation


Utility based energy emissions are classified by the energy mix within an eGrid region (see eGRID map at top). Each region has a different energy mix including renewables, hydro, coal, gas, nuclear and coal for utility-scale power generation.

Washington State electric utility generation is designated within the NWPP/WECC Northwest region, while Colorado electric utility generation is designated within RMPA/WECC Rockies region.

Viewing the chart above, what stands out clearly is that Washington State has a 52% reliance on Hydro-electric power generation, while Colorado has a 70% reliance on coal.

  • The NWPP/WECC Northwest region includes most of Oregon, parts of the northernmost California, Idaho, Nevada, Utah and Western areas of Montana and Wyoming.
  • The RMPA / WECC Rockies region extends north from Colorado to Eastern Wyoming and South to a small section of northernmost New Mexico.

State numbers can look skewed when viewed in regional terms. Washington State typically produces 65% to 70% of its energy from hydroelectric generation primarily on the Columbia and Snake rivers, yet as part of the NWPP, 52.2% is designated. A Seattle facility could lay claim to 89% hydro-electric, yet the proper designation is 52.2% per eGRID.


When accounting for Greenhouse Gas emissions within an organization, three “Scopes” are used to designate the source of the emissions. This approach provides a delineation of sources of emissions that can later be examined per an organization’s physical or administrative boundaries.

  • Scope 1 - Direct emissions from sources that are owned or controlled by an organization. Typically emissions from an organization's auto or truck fleet, though in-house generation and other combustible or fugitive emissions such as refrigerants are classified as Scope 1.
  • Scope 2 - Indirect emissions from utility purchased electricity, steam, heating or cooling.
  • Scope 3 - Indirect emissions from operations outside the control of the organization. Business-related air and public travel measured in miles per the type of travel. Depending on the depth of the emissions accounting, impacts up and downstream within the supply chain.

Electricity used for indoor Cannabis cultivation is typically classified as “Scope 2”. However, not all Scope 2 electricity is alike. The Emissions & Generation Resource Integrated Database (eGRID), published by the U.S. Environmental Protection Agency is a globally recognized source of emissions data for the electric power generated in the United States. The United States uses the eGrid system to designate environmental characteristics of the generated electric power including types of emissions, emission rates, the net generation of electricity and the energy mix.


Indoor Cannabis Cultivation Lighting Energy Use Example

As an example, here is a comparison of a 2000 sq ft indoor cannabis canopy. Using a conservative estimate of the power needs for 12 hours a day lighting only. Typical lighting scenarios reach 12 to 18 hours daily, this is only an illustrative example of the energy used for lighting.

  • Typically indoor Cannabis cultivation requires 50w of light energy per square ft.
  • 50 watts X 2000 sq ft = 100,000 watts or 100 -1000 watt lights
  • 12 hours / day = 1200 kWh daily (36, 000 kWh monthly), (432,00 kWh annual)
  • 432,000 kWh = 432 MWh


A business is seldom within sight of a utility sized power generation facility. Whether it is a smokestack from a fossil fuel burning plant, nuclear cooling towers, a dam, solar panels or wind turbines, it is often a challenge to conceptualize the impacts within close proximity of a power generation facility and other more global effects. Impacts range from toxicity in the air, water, and soil or in the extreme case of a nuclear facility a radioactive release.

In the example above, a demonstration of 432 MWh of annual electricity usage, 357 metric tons of Scope 2 CO2e is accounted for the Colorado indoor cultivation example. This is not to say that Washington State indoor Cannabis cultivation is without its own large carbon footprint of 130 metric tons of Scope 2 CO2e.


Creating efficiencies within the current cultivation systems and tracking the results maintain the quality of operations and resulting products. Scope 2 emissions are a great target for creating efficiency within a business, reducing costs and in the big picture reducing the emissions footprint of the organization.

Control of the crop, product quality and yield are factors in each cultivation process. Growing under the sun or within a greenhouse with supplemental artificial lighting can greatly reduce the Scope 2 emissions and the overall carbon footprint of an organization within the production phase of cannabis cultivation operations.

On a larger scale, an investment in a solar photovoltaic system can add value to the overall business, reduce peak load electricity charges, and reduce the monthly expense of utility fees. Yes, quite the irony of using the sun to generate electricity that is used to operate light bulbs that mimic the sun! Though it all goes back to the control of the growing area, the crop yield, and overall product quality.


Sustainability is confusing to the general public; many think of sustainability as primarily an agricultural concept due to the marketing of organic certifications. Yet, sustainability is a source of innovation and efficiency by improving economic, social and environmental aspects of a business.

Indoor cannabis cultivation is the most power intensive industry when accounting for a production facility on a square footage basis in the United States. Indoor Cannabis Cultivation is far from being sustainable, primarily due to the large Scope 2 emissions impact.

Energy use is just one part of an overall sustainability practice. Yet, in the case of indoor cannabis cultivation a heavily weighted component due to the energy intensity and large carbon footprint.


As the Cannabis industry matures, increased market competition and product differentiation will gain in importance. The provenance of the supply chain, particularly within the medical cannabis market will have the consumer demanding additional transparency of operations, specifically the carbon footprint within the production process.

While some organizations see this type of thinking as an additional task or as a component of marketing, a sustainability practice can be integrated at any stage of operations. The overall goal of the sustainability practice is to add value to the business over the long term.

Does your business use a lot of energy? Link for a complimentary solar site design with payback schedule

Learn how to embed a sustainability practice into your business.