ENERGY
GOING GREEN: HOW LED’S CAN IMPACT A GROW HOUSE FROM SEED TO SALE Authors: Wesley Whited and John Greco North America is going ‘green’ – and I don’t mean just by embracing renewables and energy efficiency. Marijuana legalization is happening at a rapid pace – Currently, 29 states and the District of Columbia allow marijuana consumption in some form, with more expected each year. The entire country of Canada has legalized marijuana. Even jurisdictions that have broadly opposed marijuana liberalization, like Alabama and Mississippi, have approved limited use for patients that suffer from severe types of epilepsy. No matter where one stands personally on this issue, the reality is that the utility industry needs to begin to plan for the electric demand to support marijuana cultivation. 1 The economics behind marijuana help explain the rapid pace of its liberalization. Per Arcview Market Research, and published on Forbes.com, marijuana sales grew 30% in 2016 to represent about $6.7 billion in legal sales. Even more, Arcview estimates that legalized marijuana has a 25% compounded annual growth rate (CAGR). As Forbes notes: “To put this in perspective, this industry growth is larger and faster than even the dot-com era. During that time, GDP grew at a blistering pace of 22%.” 2 During the dot.com boom, utilities dealt with increased electrification as massive numbers of server farms and data marts came online. Utilities are seeing power hungry, commercial-sized marijuana grow operations sprout up in their territories and can expect this trend to continue. While this growth can have a positive economic benefit to utilities, it can also impact the T&D system as utility outages have already been reported from overloading of existing utility equipment.
Marijuana grow operations are power intensive endeavors, which often run on 24-hour grow cycles. The load profile of your typical grow house is the antithesis of another energy -intensive industry - data centers. In a data center, we see a load profile dominated by the power consumption of the IT equipment and HVAC, with little consumption from lighting. (For more detail on data center energy consumption visit our Knowledge Hub). For a grow house, while HVAC and humidity control do contribute to the energy requirements, 80% of its load profile comes from lighting. This scenario presents the utility industry with an attractive option for creating lighting-specific energy efficiency measures that can supplement energy savings in traditional commercial lighting programs. A study by the Northwest Council found that in the state of Washington alone there is the potential for about 25 Megawatts of energy efficiency savings associated with marijuana cultivation 3 by 2020. Until recently, High Intensity Discharge (HID) was the only light source available to cultivate marijuana indoors. Growers often choose High Pressure Sodium (HPS) over Metal Halide (MH) because HPS produce enough of the color spectrum to support the entire grow cycle. Currently, the most popular grow lamp is a 1000w HPS lamp (including the ballast factor), which consumes about 1080w. In horticulture, we refer to the light output of the fixture in micromoles rather than lumens. In the example project below, the 1000w HPS lamp we tested produced 1975 micromoles a second, or, 1975 umol/s. LED technology is just now gaining traction with the cultivation community. Similar to other uses of LED technology, we can expect to see energy savings as high as 60%. The embedded table is from G8LED and shows the average kWh cost of electricity in each state.4 It compares the cost to operate an LED fixture and a 1000w HID light source for both the plants vegetative and flowering stages. The table below does not factor in savings from ballast factors or additional savings from HVAC. For our example project, we studied a 630w LED grow light that was used to replace the 1000w HPS lamp referenced above.
While the HPS lamp produced 1975 umol/s, the LED fixture only produced 1011 umol/s. One would assume that because the HID light source produced more umol/s, that the expected harvest would be larger than the LED light source. However, this was not the case. North America is going ‘green’ – and I don’t mean just by embracing renewables and energy efficiency. Marijuana legalization is happening at a rapid pace – Currently, 29 states and the District of Columbia allow marijuana consumption in some form, with more expected each year. The entire country of Canada has legalized marijuana. Even jurisdictions that have broadly opposed marijuana liberalization, like Alabama and Mississippi, have approved limited use for patients that suffer from severe types of epilepsy. No matter where one stands personally on this issue, the reality is that the utility industry needs to begin to plan for the electric demand to support marijuana cultivation. When we examine the color distribution of a 1000w HPS lamp, we see spikes in the spectrum from 540nm -640nm. When we examine the graph above, we see that it is during this range that the plant is absorbing the least amount of the color spectrum. Therefore, the HPS lamp needs to consume more energy and produce more umol/s to induce growth and flowering in the plant. When we examine LED technology, which is semi-conductor based, we find that it can easily control at which portion of the color spectrum it outputs. The dynamic nature of color tuning allows the LED manufacturer to create software that controls the light output to exactly what the plant needs at each stage in its growth cycle. The ability to create ‘light recipes’ is what allows LEDs to consume less energy while producing more output. DNV GL energy engineers created a sample project, simulating a grow facility switching from static color 1000w HPS lamps to 630w LED fixtures that is controlled by software to tune color output to the plant’s stage of growth. Below are the energy savings associated with the retrofit as well as the average harvest, in grams per watt consumed, for each lighting technology.
What the results show is that the highly controllable LED technology saves a tremendous amount of energy while also raising the grams produced per watt by a little over 6%. This is a win-win for both the utility that is seeking energy savings and for the marijuana cultivator who is producing a higher yield while simultaneously lowering an operating expense. Additionally, about 18% of the energy saved on this project occurred during the utility’s peak. Demand savings help the utility reduce its system peak and can have other positive impacts, such as smoothing the duck curve. In 2016, the Guardian newspaper interviewed Ron Flax, who is the sustainability examiner for Boulder County, CO. Ron speaks to how electric consumption can represent about 20% of the total cost of operating a cannabis grow house. While one would assume that operators would be flocking to LED technology to lower such a large operating expense, Ron articulates: “They approach these things with a great deal of caution, especially when you talk about things that have a crop-wide effect. Each crop cycle has a lot of dollars associated with it, so they’re really hesitant to 5 try something new and hope it works.” The authors believe this hesitation can be reduced through utility lighting programs that articulate the advantages that energy efficient lighting technologies provide in a manner that grow house owners and operators can understand – which is the increased gram/watt yield associated with LED. Economic forces and deregulation initiatives are creating new demand for electricity. The same study by the Northwest Council found that marijuana cultivation in the Pacific Northwest represents about 80-163 megawatts of new demand for the regions power systems. A larger study by the Lawrence Berkley National Laboratory found that growing legalized marijuana consumption accounts for about 1% of total electrical use from Colorado’s legalized marijuana cultivation in 2012. By 2014, the 362 grow houses in Denver represented about 2% of the city’s electric use and statewide. 6 Utility Dive reported in late 2015 that 45% of Denver’s load growth was coming from marijuana cultivation. According to Alice Jackson, VP of Regulatory Affairs for Xcel Energy, who provides power to Denver: “We now have on an annual basis, over 300 GWh consumed from our 7 customers that are doing growth of marijuana or cannabis in their areas.” These trends are part of a larger move toward electrification; if you are curious about the future of energy and are looking for an in-depth analysis of global or regional trends, please download the DNV GL Energy Transition Outlook. As utilities forecast future demand and calculate capacity needs, accounting for marijuana production is a new contributing factor that will increase in importance. Utilities can then develop schemes for indoor agriculture that help encourage energy efficiency in grow houses. Because lighting makes up the substantial bulk of a grow house load profile, LED fixtures are a simple solution that can make a tremendous impact to load. As new LED lighting products come to market
that both increase production and reduce energy consumption, grow house operators will have more confidence that the technology will not impact the quality of their product. For more information on other DNV GL lighting efforts, please visit our Smart Lighting Solutions Knowledge Hub.
DNV GL has successfully designed and implemented programs on behalf of our utility clients for four years. Our team has significant project experience in both retrofitting and new construction projects. We work through the project life-cycle to identify, justify and evaluate energy saving measures and provide post-installation engineering review to verify savings. Our team is available to work directly with large institutions to assist them with Smart Lighting Solutions projects. For more information, please contact Wesley Whited. Wesley Whited Senior Consultant - Smart Lighting Solutions DNV GL Mr. Whited has seven years’ experience in the commercial lighting market ranging from project management to sales. Mr. Whited is a graduate of West Virginia University (WVU) and holds a MBA from Capital University in Columbus, OH. John J. Greco Principal Engineer - Program Development and Implementation DNV GL John J. Greco. John is a D.O.E. Certified Data Center Energy Practitioner, Certified Energy Manager, Certified Measurement and Verification Professional, Certified AEE Building Sustainable Energy Technician Trainer, Certified Lighting Energy Technician, and holds a Bachelor of Science degree in Electrical Engineering Technology from the State College of New York.
Footnotes 1
http://www.governing.com/gov-data/state-marijuana-laws-map-medical-recreational.html
2
https://www.forbes.com/sites/debraborchardt/2017/01/03/marijuana-sales-totaled-6-7-billion-in-2016/#5100271575e3
3
https://www.nwcouncil.org/news/blog/marijuana-demand-forecast/
4
https://archive.theweedblog.com/how-much-energy-does-an-led-marijuana-grow-light-save/
5
https://www.theguardian.com/us-news/2016/feb/27/marijuana-industry-huge-energy-footprint
6
https://www.theguardian.com/us-news/2016/feb/27/marijuana-industry-huge-energy-footprint
7
http://www.utilitydive.com/news/pot-power-how-utilities-and-regulators-are-dealing-with-the-budding-mariju/409172/