Even in the early days of solar photovoltaics, cannabis growers recognized the potential benefits of harnessing the power of the sun to cultivate their lucrative crops. Mendocino County in California, for instance, saw a surge in both the growth of cannabis production and off-grid solar in the late 1970s as farmers needed the means to live and operate remotely to hide their then-clandestine cultivation.
Fast forward nearly four decades and the relationship between solar photovoltaics and the cannabis industry is still going strong though for entirely different reasons. Currently, 33 states have legalized medical marijuana with ten states and the District of Columbia allowing for recreational use among adults. However, with more and more states legalizing marijuana, demand for quality cannabis is significantly increasing the energy demand of growers and putting a strain on both their bottom line and the electrical grid.
Now, more than ever, solar PV and energy storage devices can support the cannabis industry by reducing electric bills and contributing to the production of a greener, more environmentally-friendly product. With some studies suggesting up to half of the production costs associated with indoor cannabis production come just from the power bill, solar plus storage can provide a significant boost to a grower’s bottom line as well as a powerful marketing advantage for any company.
The Energy Intensity of Cannabis Production
While the legalization of marijuana has prompted some growers to return to outdoor cultivation (or to rely on greenhouses or other mixed-light structures), most cannabis growing businesses operate indoors in order to better control environmental conditions and to optimize yields and product potency. Indoor facilities require a great deal of artificial lighting during the various stages of cannabis growth, including near round-the-clock lighting for the first several months of a cannabis plant’s life. In fact, a 2014 Northwest Power and Conservation Council report estimated a grow operation cultivating only four plants would draw as much power as 29 refrigerators!
While expensive and energy-intensive in its own right, indoor lighting also creates additional space heating and condenses waters which can both be detrimental to the growing process. This prompts the inclusion of sophisticated HVAC systems to manage environmental conditions such as humidity, CO2 levels, and temperature in the facility, further increasing energy costs and carbon footprint and negatively impacting a grower’s bottom line.
How high is that carbon footprint you ask (pun definitely intended)? Evan Mills’ famous 2011 study on the carbon footprint of indoor cannabis facilities found that producing 1 kg of cannabis created nearly 4600 kg of CO2. Some experts have even estimated the industry at large produces more than 15 million metric tons of CO2 emissions on an annual basis.
Additional energy draws for a given grow facility might include irrigation systems, security, and general office equipment such as computers or packaging equipment, not to mention any laboratory-rated processing equipment. In total, the energy-intensity of an indoor grow facility can be on par with that of a data server facility (or several hundred times more intensive than a typical office building).
This means that as cannabis legalization becomes more widespread and accepted, growers will need more and more energy to cultivate cannabis and meet demand. Unfortunately, most of this energy is currently coming from fossil fuel generation like coal or natural gas. Legal marijuana is starting to contribute significantly to climate change with a larger carbon footprint, but it doesn’t have to be this way!
Local Governments Feel the Heat
In states where cannabis has been legalized, local energy providers are already feeling the impacts of legal cannabis cultivation. For instance, energy consumption in Denver saw a steady rise after Colorado legalized, with up to 4% of the total energy demand in the city coming from cannabis cultivation. As a response, the city’s Department of Environmental Health released a “Cannabis Environmental Best Management Practices Guide” to help stem the rising energy demands. The guide includes suggestions for reducing environmental impacts and energy management strategies while factoring in the economics of the cannabis cultivation business.
The Grower’s Paradox
One seemingly obvious solution to the growing energy consumption issue in the cannabis industry is the option of growing outdoors. According to one article, growing indoors consumes up to 18 times more energy than outdoors. However, this is not appealing to many growers since it means having less control over the temperature and moisture conditions they need to manipulate in order to provide the best product. If only there was a way to harness the natural power of the sun while maintaining climate control…
Sunlight is the Solution
Of course, there is a very simple way to use the energy of the sun and still grow indoors—photovoltaic solar panels. As cannabis companies watch their power bills soar, some are taking advantage of generous tax credits and installing large solar arrays on their cultivation facilities. By harnessing solar energy to power their lighting and HVAC systems, cannabis companies can make a huge dent in their monthly power bills while at the same time reducing their greenhouse gas footprint and doing right by the planet. Even if solar power is not feasible to produce all of the energy needed, simply reducing the demand helps drive down power costs and overall consumption in a big way.
In Colorado and Massachusetts, for instance, cannabis growers face staggering demand charges and are therefore highly incentivized to structure their operations to consume electricity as consistently as possible day to day. Some facilities are choosing to upgrade their lighting systems to include more light-emitting diodes (LEDs) rather than the more inefficient metal halide or high-pressure sodium lamps. Although there is still some skepticism about using LEDs for fear of diminished product quality, they are still growing in popularity as they are more than able to provide sufficient lighting during the flowering phase of cannabis cultivation (all with less heat and energy required).
Another increasing trend is the integration of energy storage devices to improve the resiliency of the cannabis facility itself. While batteries are insufficient to sustain the power needs of an entire cannabis facility in the event of a prolonged outage, they could prove invaluable in keeping the lights on for more sensitive operations and processes such as plants still in the vegetative state. Without sufficient lighting, these plants will begin to flower prematurely, resulting in reduced yields, lower potencies, and a potentially massive financial hit for the grower.
Paired with a solar power system, energy storage devices hold enormous promise for cannabis growers looking to ensure energy resiliency. What’s more, they can even help reduce peak demand by deploying stored electricity during periods of peak demand (thus avoiding costly demand charges that could potentially make up 30 to 70% of a customer’s energy bill). Together, solar plus storage also sends a powerful environmental message that is sure to resonate with the end cannabis consumer (a customer base regularly found to be more likely than the market average to purchase sustainable products).
Sam Henke is a writer and sustainability professional living in Boulder, Colorado. He is a recent graduate of a Professional Master's Degree focusing on Sustainable Food Systems, supplementing his broader experience in sustainability consulting, marketing, strategy, and communications. For more information or project proposals, contact Sam at [email protected] or connect with him on LinkedIn.