Tag Archives: energy

Understanding Dissolved Oxygen in Cannabis Cultivation

By Aaron G. Biros
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Oxygen plays an integral role in plant photosynthesis, respiration and transpiration. Photosynthesis requires water from the roots making its way up the plant via capillary action, which is where oxygen’s job comes in. For both water and nutrient uptake, oxygen levels at the root tips and hairs is a controlling input. A plant converts sugar from photosynthesis to ATP in the respiration process, where oxygen is delivered from the root system to the leaf and plays a direct role in the process.

Charlie Hayes has a degree in biochemistry and spent the past 17 years researching and designing water treatment processes to improve plant health. Hayes is a biochemist and owner of Advanced Treatment Technologies, a water treatment solutions provider. In a presentation at the CannaGrow conference, Hayes discussed the various benefits of dissolved oxygen throughout the cultivation process. We sat down with Hayes to learn about the science behind improving cannabis plant production via dissolved oxygen.

In transpiration, water evaporates from a plant’s leaves via the stomata and creates a ‘transpirational pull,’ drawing water, oxygen and nutrients from the soil or other growing medium. That process helps cool the plant down, changes osmotic pressure in cells and enables a flow of water and nutrients up from the root system, according to Hayes.

Charlie Hayes, biochemist and owner of Advanced Treatment Technologies

Roots in an oxygen-rich environment can absorb nutrients more effectively. “The metabolic energy required for nutrient uptake come from root respiration using oxygen,” says Hayes. “Using high levels of oxygen can ensure more root mass, more fine root hairs and healthy root tips.” A majority of water in the plant is taken up by the fine root hairs and requires a lot of energy, and thus oxygen, to produce new cells.

So what happens if you don’t have enough oxygen in your root system? Hayes says that can reduce water and nutrient uptake, reduce root and overall plant growth, induce wilting (even outside of heat stress) in heat stress and reduce the overall photosynthesis and glucose transfer capabilities of the plant. Lower levels of dissolved oxygen also significantly reduce transpiration in the plant. Another effect that oxygen-deprived root systems can have is the production of ethylene, which can cause cells to collapse and make them more susceptible to disease. He says if you are having issues with unhealthy root systems, increasing the oxygen levels around the root system can improve root health. “Oxygen starved root tips can lead to a calcium shortage in the shoot,” says Hayes. “That calcium shortage is a common issue with a lack of oxygen, but in an oxygen-deprived environment, anaerobic organisms can attack the root system, which could present bigger problems.”

So how much dissolved oxygen do you need in the root system and how do you achieve that desired level? Hayes says the first step is getting a dissolved oxygen meter and probe to measure your baseline. The typical dissolved oxygen probe can detect from 20 up to 50 ppm and up to 500% saturation. That is a critical first step and tool in understanding dissolved oxygen in the root system. Another important tool to have is an oxidation-reduction potential meter (ORP meter), which indicates the level of residual oxidizer left in the water.

Their treatment system includes check valves that are OSHA and fire code-compliant.

Citing research and experience from his previous work, he says that health and production improvements in cannabis plateau at the 40-45 parts-per-million (ppm) of dissolved oxygen in the root zone. But to achieve those levels, growers need to start with an even higher level of dissolved oxygen in a treatment system to deliver that 40-45 ppm to the roots. “Let’s say for example with 3 ppm of oxygen in the root tissue and 6ppm of oxygen in the surrounding soil or growing medium, higher concentrations outside of the tissue would help drive absorption for the root system membrane,” says Hayes.

Reaching that 40-45 ppm range can be difficult however and there are a couple methods of delivering dissolved oxygen. The most typical method is aeration of water using bubbling or injecting air into the water. This method has some unexpected ramifications though. Oxygen is only one of many gasses in air and those other gasses can be much more soluble in water. Paying attention to Henry’s Law is important here. Henry’s Law essentially means that the solubility of gasses is controlled by temperature, pressure and concentration. For example, Hayes says carbon dioxide is up to twenty times more soluble than oxygen. That means the longer you aerate water, the higher concentration of carbon dioxide and lower concentration of oxygen over time.

Another popular method of oxidizing water is chemically. Some growers might use hydrogen peroxide to add dissolved oxygen to a water-based solution, but that can create a certain level of phytotoxicity that could be bad for root health.

Using ozone, Hayes says, is by far the most effective method of getting dissolved oxygen in water, (because it is 12 ½ times more soluble than oxygen). But just using an ozone generator will not effectively deliver dissolved oxygen at the target levels to the root system. In order to use ozone properly, you need a treatment system that can handle a high enough concentration of ozone, mix it properly and hold it in the solution, says Hayes. “Ozone is an inherently unstable molecule, with a half-life of 15 minutes and even down to 3-5 minutes, which is when it converts to dissolved oxygen,” says Hayes. Using a patented control vessel, Hayes can use a counter-current, counter-rotational liquid vortex to mix the solution under pressure after leaving a vacuum. Their system can produce two necessary tools for growers: highly ozonized water, which can be sent through the irrigation system to effectively destroy microorganisms and resident biofilms, and water with high levels of dissolved oxygen for use in the root system.

Building or Converting to a Greenhouse? Four Considerations for Commercial Growers

By Taylor Engert
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Successful cannabis cultivation practices leverage commercial agricultural industry practices for the most efficient and cost-effective production of the crop. Since the 1990s, the cannabis industry has cultivated primarily in indoor warehouses and outdoor farms, however the industry is experiencing a significant shift toward greenhouses.

Shelly Peterson, vice president of light product solutions at urban-gro, joined a recent panel of industry experts including Shivawn Brady, chief executive officer and founder of Seva Crop Consulting, and Karl Keich, executive director at Canna Consulting Group, at the Marijuana Business Conference in Orlando, Florida, to discuss how to transition from an indoor or outdoor grow to a greenhouse facility.

What are the considerations when deciding between a warehouse and greenhouse? The panel shares four factors around the costs and operational challenges, and the benefits of a greenhouse.

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The panel at the Marijuana Business Conference.

Maximize Efficiency in Every Process

Why are cannabis cultivators looking toward greenhouses? Peterson says it is all about efficiency. “In a warehouse, electricity costs can run up to 50 percent of the total cost of goods sold, which is a tremendous amount that can be decreased by switching to a greenhouse,” says Peterson. “In a greenhouse, you can add supplemental lighting to augment what the plant is receiving from the sun.”

For cultivators, Peterson noted that it is critical to ensure growers have experienced vendors and advisors on the team to help maximize the efficiency of the greenhouse. “As the cost of this product comes down, the efficient growers will be the ones in it for the long haul,” added Peterson.

Construction vs. Operating Costs

A greenhouse facility that urban-gro helped bring to operation.
A greenhouse facility that urban-gro helped bring to operation.

The panel identified upfront cost as one of the biggest challenges faced when building out a greenhouse. “The cost of retrofitting a warehouse and building a greenhouse are similar, but where you will save is in the operational costs,” says Peterson. “Lighting can be up to one third of your total cost in indoor facilities, when you switch to a greenhouse that cost can be reduced by 50 to 70 percent.”

Brady acknowledged that some traditional greenhouses have challenges in controlling the environment, but automated greenhouses offer retractable roofs and siding. “If you have the resources to invest in your greenhouse system upfront, that is generally a better way to save money in the long run,” says Brady. “Managing pests in greenhouses can also become very challenging if you don’t have the proper climate regulations.”

Lighting for Your Greenhouse

One of the greatest benefits of growing in a greenhouse is the ability to source natural light. But what about the required light levels? Peterson pointed out that light levels change throughout the year and the plants have different light needs in different stage. Supplement with a lighting system that can read the natural light levels received over any given period of time and be adjusted accordingly. “Greenhouse facilities also need to be outfitted to meet the needs of the cannabis plant, which differ in some ways from other agricultural crops,” says Peterson.

Peterson explained that every light is designed with a different purpose in mind. “There are different lights for indoor warehouse facilities where the lighting system provides 100 percent of the available light for cannabis growth versus supplemental lighting for greenhouses,” Peterson adds. “The key is to measure how much light is actually delivered by the sun on a daily basis, which changes throughout the year; at urban-gro, we supplement the facility with light fixtures that will not create shadowing during hours of sunlight and adjust to reach the optimal collective light levels.”

With LED lighting a hot button topic, Peterson explained that the most important consideration for any light fixture, whether LED or HPS, is it’s efficiency capacity. “It all depends on the budget and payback period and a lot of numbers need to be crunched,” says Peterson. “Yield is directly correlated to light; planning properly, sealing your environment, making sure you have the right target DLI, and buying good light meters, are all key.”

Make a Positive Impact and Quality Product

Brady noted that industry leaders are conscious of positive impact towards human health and environmental stewardship when moving to a greenhouse. Cultivators may find the process challenging initially, however the facilities are quite easy to operate and manage, and allow stress-free cultivation of commercial-scale crops.

Keich added that the cannabis industry is becoming more like commercial agriculture. By utilizing the correct technologies and regulators, greenhouse cultivation makes the crop smell, taste and look that much better. “Let’s use natural sunlight to minimize costs and be environmentally friendly to produce a superior product,” says Keich.

Peterson wrapped up by stressing that cultivators should evaluate the greenhouse environment and lighting to improve their bottom line. “Look at the most efficient way to lower your cost of goods sold. Lighting is a very big component to that,” she continued. “Make sure you evaluate the efficiency of the fixture and ask the questions: Why are we targeting this light level? Is the color spectrum correct? Are you measuring in micromoles per watt? These are all different questions, however figure out how much light is coming out of the fixture and verify it for yourself, and you will be successful,” says Peterson.

MedicineManTechGrow

Legal Cannabis Industry’s Energy Bill Not So Alarming

By Aaron G. Biros
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MedicineManTechGrow

New Frontier, a financial data analysis firm, recently released a report that caused a media frenzy over the cannabis industry’s alarmingly high energy bill. The Washington Post published an article with the headline “The Surprisingly Huge Energy Footprint of the Booming Marijuana Industry.” Denver news publication, Westword, posted an article with the headline “Legal Marijuana Used Over $6 Billion in Energy Last Year, Report Says.” There are dozens of articles published suggesting the legal cannabis industry’s energy consumption has a $6 billion price tag, which is misleading.

What’s the problem? The $6 billion figure that New Frontier cites comes from a 2012 research study that estimates the energy footprint for legal and illicit markets. That means the $6 billion estimate includes the legal cannabis industry and the black market’s energy footprint. To put it in perspective, the size of the entire legal cannabis industry in the United States was less than that in 2014 at $4.6 billion, according to the ArcView Group.

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The projected energy demand for growing in the Northwest through 2035, from the New Frontier report.

According to Giadha Aguirre DeCarcer, founder and chief executive officer of New Frontier, only including the legal market would significantly reduce the size of this estimate. “Dr. Mills’ study looked to assess the total energy use associated with marijuana in the US, not just that of the nascent legal marijuana industry; including this holistic view is an important growth determinant for the legal market as the U.S. transitions from a predominantly illicit production environment,” says Decarcer.

Dr. Evan Mills, energy analyst at the Department of Energy and member of the UN Intergovernmental Panel on Climate Change, conducted the 2012 research study and is a senior advisor on the New Frontier report.

Brett Roper, founder and chief operating officer at Medicine Man Technologies, believes those numbers still need to be adjusted. “Dr. Mills’ study is based on pre-2011 data and sources that date back as far as 2003,” says Roper. “The study provides figures that are, quite frankly, outdated based upon changes in the industry related to cultivation and production efficiency.” The study focuses on cultivation increments of sixteen square feet consuming 13,000 KW per year that, according to Roper, is not reflective of current indoor cultivation technology and energy consumption metrics.

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A back-end view of Medicine Man Technologies’ indoor production facility

According to Roper, today’s efficiencies, scalable cultivation operations and new technology could explain the overestimate from five years ago. “We are a Tier III operator that produced approximately 5,100 (+/-) pounds of dried cured flower in 2015 and have a total power bill of approximately $420,000 for the year,” he says. Note that the company had roughly $18 million in revenue in 2015. “Using this metric we have a total energy billing of approximately $83 per pound grown.” According to Roper, they cultivate completely indoors with HPS lights that are not particularly energy-efficient, so this estimate is relatively conservative.

MedicineManTechGrow
Medicine Man Technologies’ approximately 40,000 sq. ft. cultivation facility.

Dr. Mills’ research cites much higher numbers for the cost of energy per pound of finished product than Roper’s findings. “From the perspective of a producer, the national-average annual energy costs are approximately $5500 per module or $2500 per kilogram [roughly 2.2 pounds] of finished product,” says Dr. Mills. That would suggest the average cost of energy for indoor growing to be above $1,000 per pound, roughly half the current average wholesale price. These numbers would mean that cannabis growers, on average, lose roughly 50% of their total revenue to their energy bill. Medicine Man Technologies’ energy usage is less than 3% of their total revenue.

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Xcel, a Colorado utility, showing the rise in electricity demand for cultivation.

The New Frontier report does provide caveats on the use of Dr. Mills’ research. “While this analysis was conducted before many of the recent advancements in cultivation technologies, it highlights the significant energy-related environmental impact of marijuana production, and makes the issue of energy efficiency not just one of competitive advantage but also one of environmental sustainability.”

New Frontier’s CEO, DeCarcer, stresses that their report is intended to serve as a starting point to a much broader exploration of energy use in cannabis. “We are already in the process of establishing a partnership through which New Frontier will ingest real time energy-use data from cultivators across different legal markets for analysis in our next report,” says DeCarcer. “Our goal is to build on the work done by Dr. Mills and others in order to ensure that we are providing the most accurate representation of where the industry currently is, and where it is headed.”

Regardless of the discrepancies, this kind of discourse is great for prompting innovation and getting people to think about the environment. It is very important to examine the energy footprint of cannabis cultivation as it raises questions regarding energy efficiency, which would help the industry’s long-term environmental sustainability.

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Biros' Blog

Sustainability of Cultivation in 2016, Part II

By Aaron G. Biros
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soslticefarms_feb

In the second part of this series, I speak with Alex Cooley, vice president of Solstice, to find out what particular solutions growers can use to increase efficiency. Last month, I introduced the challenge of growing cannabis more sustainably. To recap, I raised the issue of sustainability as an economic, social and environmental problem and referenced recent pesticide issues in Colorado and carbon footprint estimates of growing cannabis.

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The growers at Solstice put their plants under a trellis net to increase yield.

Alex Cooley is the vice president of Solstice, a cultivation and processing business based in Washington. Solstice is at the forefront of the industry for innovating in energy, water and raw materials efficiency. I sat down with Cooley to discuss exactly what you can do to grow cannabis sustainably.

“Switching to outdoors or greenhouse will always be more sustainable than indoor, but depending on the type of facility, energy efficiency and specifically lighting should be at top of mind,” says Cooley. “Just looking at your bottom line, it is cheaper to use energy efficient lighting sources such as plasma or LED lighting, which will reduce your need for air conditioning and your overall energy consumption.”

Looking into sustainable technologies is one of the quicker ways to improve your overall efficiency. “We are big believers in VRF [variable refrigerant flow] HVAC systems because it is one of the most energy efficient ways to cool a large space in the world,” adds Cooley. “Use a smart water filtration system that gets away from wasting water by catching condensate off AC and dehumidifiers, filtering and then reusing that water.”

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Indoor cultivator facilities use high powered lights that give off heat, requiring an efficient air cooling system like VRF HVAC.

Utilizing your waste streams is another relatively simple and cost effective practice to grow cannabis sustainably. “Our soil and biomass goes through a composting company, we recapture any of our waste fertilizer and runoff for reuse,” says Cooley. “We try to use post-consumer or fully recyclable packaging to reduce what would go into the waste streams.”

So some of the low hanging fruit to improve your bottom line and overall sustainability, according to Alex Cooley, include things like reusing materials, composting, increasing energy efficiency and saving water. These are some of the easily implementable standard operating procedures that directly address inefficiency in your operation.

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The tops of plants are beginning to flower in this Solstice indoor facility.

In the next part of this series, I will discuss Terra Tech’s approach to sustainable cultivation, which utilizes the “Dutch hydroponic greenhouse model” on a large scale growing produce such as thyme and basil, but are now taking their technologies and expertise to the cannabis industry. I will also discuss the benefits of using a third party certification, Clean Green Certified, to not only help grow cannabis more ecofriendly, but also market your final product as such. Stay tuned for more in Sustainability of Cultivation in 2016, Part III.

From Produce to Cannabis: The Future of Indoor Agriculture

By Aaron G. Biros
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Throughout the United States, a majority of cannabis for medical and adult use is grown indoors, which requires a tremendous amount of energy and is generally inefficient. State regulators and cultivators alike are beginning to notice the benefits of greenhouse and outdoor-grown cannabis, primarily for energy efficiency and environmental sustainability.

Basil plants ready for packaging and shipping at the Edible Garden facility in Belvidere, New jersey
Basil plants ready for packaging and shipping at the Edible Garden facility in Belvidere, New jersey

Terra Tech, a publicly traded company, cultivates environmentally sustainable produce through its subsidiary, Edible Garden, in Belvidere, New Jersey. Utilizing Dutch hydroponic cultivation methods, integrated pest management and computer-controlled automation, Edible Garden grows certified organic herbs such as thyme and basil in their greenhouses in New Jersey.

Poinsettias ready for distribution at Edible Garden facility in Belvidere, New Jersey
Poinsettias ready for distribution at Edible Garden facility in Belvidere, New Jersey

Edible Garden is certified by the Global Food Safety Initiative (GFSI), which provides internationally recognized benchmarks and guidance for managing food safety and meeting standards. According to Ken VandeVrede, chief operating officer of Terra Tech, the company plans to take these cutting-edge practices and standards from cultivating produce to the cannabis industry to grow quality, sustainable and safe cannabis in states where it is currently legal.

The company is actively making its operations more environmentally sustainable via greenhouse cultivation, Dutch style hydroponics, shipping locally, and integrated pest management. “We plan on implementing guidance from our two years of GFSI certification and our organic certification along with all of our practices from the food side and bring them to cannabis; for us, it is just another plant,” says VandeVrede. With the help of computer automation, he says they can cultivate cannabis at the commercial scale, creating more homogeneity by removing human elements and utilizing environmental controls. Through computer automated blackout curtains in their greenhouses, they plan to minimize energy usage by using natural sunlight when possible.

“The procedures are very similar across industries so we are creating our own internal standards for cannabis cultivation,” says VandeVrede. “We are trying to be at the forefront of the industry and set the standard for growing cannabis, because right now, there are no standards in place.”

Mint plants ready for harvest at the Edible Garden greenhouse
Mint plants ready for harvest at the Edible Garden greenhouse

Terra Tech has already started its move into the cannabis industry via its subsidiary, IVXX LLC, which makes medical cannabis extracts for dispensaries in California. The company has also broken ground on cultivation and production facilities in Nevada and dispensaries in California, and submitted an application for licenses in Maryland. “Terra Tech is doing everything with vertical integration in mind; we will control the cultivation, bringing experience from our agricultural background to cultivate high quality and high yield cannabis, making oil and extracts with it to sell in our dispensaries,” adds VandeVrede.

Looking to the future of cannabis cultivation, Terra Tech’s plan is to keep environmental sustainability at top of mind. “As a company we are growing indoor, but moving toward greenhouse cultivation across the board”, says VandeVrede. “Our focus on expansion will be [include] greenhouse-grown cannabis, which is a lot more efficient, saving us money but more importantly reducing our overall carbon footprint.” With more companies adopting these sustainable farming practices, the industry might soon usher in a new era of environmentally friendly cannabis cultivation.