Pairing solar with the energy-hungry marijuana growing market seems like a no brainer. Indoor grow houses require an incredible amount of electricity to power artificial lighting, fans, dehumidifiers, water pumps and many more elements at all hours. As more states legalize recreational marijuana, the electric grid is bound to suffer from this increased 24/7 demand. Surely solar can help even things out?
The truth is that the relationship between solar power and cannabis cultivation is complicated. Solar can absolutely help a marijuana operation reduce its electric bills, but the real question is how much can it actually contribute to a grower’s bottom line?
As marijuana prohibition ends, more growth operations could transition outdoors since plants must no longer be hidden from view. When cannabis crops move outside or into mixed-light facilities (like greenhouses), less electricity is needed to establish an indoor ecosystem. But indoor grow operations are still dominant, and any bit of energy assistance solar can give these companies would come as a big relief—to growers and utilities.
How cannabis grow operations use electricity
Large-scale marijuana grows can be separated into three categories: indoor, outdoor and mixed-light. Outdoor cannabis agriculture still requires some electricity although the plants are open to sunshine. Mixed-light grows are equivalent to familiar greenhouses, needing fans and other temperature controls to produce a harvestable crop. Indoor agriculture has no windows and is 100% artificially lit, requiring a tremendous amount of electricity.
Medical marijuana is legal in 30 states/districts while recreational use is presently legalized in nine: Alaska, California, Colorado, Maine, Massachusetts, Nevada, Oregon, Washington and Washington, D.C. While outdoor grows may become more prevalent in California, certain climates may not be able to support them, such as Maine or Alaska. Grow operations in these areas may remain inside out of necessity, putting a strain on the electric grid.
Grows use electricity in many ways, but some of the more common usages per grow category are:
- Outdoor: irrigation, security
- Indoor: artificial lighting, air conditioning, CO2 injection, dehumidification, ventilation, irrigation, security
- Mixed-light: same as indoor, but less
The stages of cannabis growth are seed, vegetation and flower. Seeds/clones typically need 24 hours of light for up to four weeks before stems and leaves arrive (vegetative growth), and then up to five weeks of 18-hour days of light are needed to pass into the flowering stage. Flowers only need 12 hours of light each day, to invoke a circadian response for blooming. Flowering lasts 60 days and then the plant is ready to harvest.
The amount of artificial lighting used during certain stages produces a lot of heat in greenhouses and indoor grows, so air conditioners keep everything temperature-controlled. Cannabis plants produce water vapor during growth, so dehumidification systems keep climates regular, as humidity-induced mold can destroy crops. Add in irrigation systems and CO2 injection to help feed plants, and it’s obvious to see the 24/7 electricity needs of indoor and mixed-light grow operations.
According to a widely cited 2012 independent research report by Evan Mills, a typical indoor marijuana grow room has the same power density (200 watts per square foot) as a data center. HVAC, dehumidification and ventilation makes up 50% of a grow’s electricity load, and lighting accounts for 33%+.
The industry overwhelmingly turns to high-pressure sodium lights for its lighting needs, which are a huge power-suck. LED lights have been suggested, and some utilities offer rebates to those switching to LED lighting, but many growers prefer using what they know best—high-pressure sodium light bulbs that give off a lot of heat. As the industry becomes more comfortable with LED lighting, it could drop lighting costs from 33% of the overall picture down to near 25%.
Natural sunlight supplies most of the light needed in a greenhouse/mixed-light grow operation, and The Cannabist estimates growers use one-third to one-half as many lamps in a greenhouse than in a 100% indoor grow. Greenhouses need supplemental, artificial light to mimic daylight from October to March, when long nights typically trigger plants to flower and slows growth. While greenhouses use less electricity than indoor grows, their electric bills can still be fairly high.
Solar’s role in the cannabis industry
Solar and marijuana are ubiquitous. The early, prohibited cannabis industry used solar panels to offset its electric load so the government wouldn’t be able to pinpoint high utility bills to illegal grow operations. But the scale of legal cannabis grows today is a bigger energy concern than the few hidden plants of yesterday.
The vast majority of grows are indoor because product is more easily controlled, said Duncan Campbell, vice president of project development at Scale Microgrid Solutions, a consulting business that assists indoor farmers (specifically, cannabis) in integrating energy efficiency solutions into their facilities.
“It is fair to say that the market is shifting to outdoor and greenhouse because those segments were virtually zero before legalization,” he said. “The question is, ‘Will indoor grows be eliminated?’ Let’s say the industry shifts to 50% indoor, 50% outdoor/greenhouse. Given how fast this industry is growing, the indoor segment is still going to be a big problem for utilities. Even if it’s 25% indoor, it will still be a big issue.”
Many growers turn to indoor operations because indoor-grown product fetches a premium over outdoor-grown product. You can also get much more product out of an indoor grow. The higher cost of production is worth it for higher revenues (even though electric needs use up 47% of a crop’s wholesale price).
“The hardest part of starting a growing operation is finding a place to do it,” Campbell said. “Once you have land you want to maximize your profit, so they’re still going indoor.”
Indoor grows may have the roof-space for solar, but the amount of solar needed to make a difference is often unobtainable, said Anya Gordon, CEO at GroTec Builders, a full-service consulting and design/build firm for the cannabis industry.
“The amount of power that an indoor facility is consuming is staggering,” she said. “We’re on par with server rooms. The scale and size of a solar installation that you would have to have to fully supplement that power is significantly larger than what most facilities could even consider.”
For solar installers really interested in getting a foot in the cannabis door, power independence probably isn’t the best pitch.
“[Growers] are in the business of eating electricity and producing a product,” Campbell said. “We’re not taking any of these people off-grid. With solar, if I’m lucky, I can make 25% of their power. These are really power-dense facilities. It’s a good market for high-efficiency panels, power optimizers, anything that can increase power.”
John Morris, vice president of market development for D+R International, a long-time energy consulting firm that has established energy efficiency standards with the DOE and EPA, works with utilities, growers and equipment manufacturers to promote energy efficiency. He suggests solar installers go after a more accessible cannabis market: medical grows in residential buildings.
“These grow ops that are using residential buildings in residential neighborhoods are putting tremendous stress on the grid system,” he said. “You have a chance for solar to actually put a dent in some of these medical grow facilities in residential buildings versus trying to offset million-dollar utility bills per month with warehouses.”
Growers in legal markets have to register with state entities, and anyone can find those locations. This could be a very valuable customer list to solar installers. But if these grows are still too small for solar companies, Morris said only one large warehouse grow needs to buy into solar to start a movement.
“You just need to find one or two that are going to be that demonstration project model for you,” Morris said. “You want that thought leadership entity that can really drive it, and then showcase that to all the other growers: ‘Look, this can be done, the product hasn’t turned out bad, the yield is still the same, and now we can tell a story about our carbon footprint that’s different than all of our competitors.’”
Campbell also suggested solar installers go the feel-good marketing route to hook some of the more successful, long-term-thinking facilities looking to establish a “sun-grown” brand.
“All the growers are trying to figure out what their brand is,” he said. “It’s not surprising that the cannabis consumer market tends to be closely correlated to those who care about the environment. There is an opportunity to say, ‘We run on solar and give you a super high-grade consistent product.’”
And if that isn’t enough for some growers, maybe the promise of backup power will convince them to go solar.
“If you lose power for a day you could lose $1 million,” Campbell said of some of the larger grow houses. “Backup power is worth a true amount of dollars in the cannabis industry.”
Microgrids and solar+storage options provide growers with a cleaner backup option than diesel generators.
“There’s an affinity for the independence that solar can give a grower,” Morris said. “Microgrids give a resiliency message. It gives the grower confidence that if anything goes down on the site, they have that backup.”
Hurdles, not roadblocks
While solar is possible right now in the legal cannabis industry, it still comes with its risks.
Solar financing is an issue since many cannabis operators haven’t existed for more than a few years. And “a few years” is a long time in this emerging industry, where many growers are just looking to make a quick buck, building shaky operations, not concerned about 10 years down the line when solar pays itself back. Campbell said that will change as the industry matures.
“If you look at the early recreational states, the first entrants were very DIY. Those people aren’t interested in seven-year paybacks; their plan is seven months,” he said. “Now that those first markets have existed for a while and moved state by state, this is a real industry with real investors. This next wave of cannabis facilities and operators do have a vision that goes beyond six months.”
Growers also can’t take advantage of that coveted solar ITC since they’re still federally unrecognized businesses. Holding companies often own the land and grow facilities so these operations function legally, and working through them is the only way to take advantage of the ITC.
Familiar with the differences of AHJs from county to county, solar installers should not be surprised that the cannabis industry has its own inconsistent requirements. For example, Ohio’s medical marijuana industry has a limited number of grow licenses available, so there are a set amount of organizations able to look into solar. Oregon and California did not cap the number of their licenses and the options are endless. Oregon did cap the amount of space its indoor commercial growers can use—only 10,000 sq. ft. While some grow operations use every inch possible for growing product, Oregon’s size restrictions probably leave some extra room on the ground for a few solar panels. Understanding each jurisdiction’s requirements can help solar installers narrow their focus to grows with the best solar potential.
Solar is often looped into the larger energy efficiency discussion within the cannabis industry, something growers often don’t like to talk about. Morris estimates that even with significant efficiency rebate programs from utilities, only 1 to 2% of growers nationally use efficient manufacturing products like LED lighting, so solar is often not at the top of their must-have upgrades.
“If [the energy efficiency movement] isn’t happening in states like Colorado, in more mature areas with utilities like Xcel [Energy] with a robust energy efficiency program, it means we have a lot of hard work to do to really educate the growers,” he said.
Gordon and many others are dedicated to establishing standards and best practices for the young cannabis industry because it’s a free-for-all right now, she said. Until sustainability is required, energy efficiency and solar won’t be given a second thought.
“When it comes down to putting the rubber to the road, efficiency measures are expensive up front to install,” she said. “Because so many people don’t know whether they’re going to be around in a year, they want cheap and easy.”
States may lead the way in bringing stabilization to legal marijuana. California’s drafted regulation would require indoor grows to get 42% of their energy from renewables. Solar installers then could have easier conversations.
Energy efficiency becomes more of a concern once the market evens out. The price of marijuana will drop with competition, but energy rates will stay the same. Businesses can’t stay in the game if they’re not thinking about their energy use and how to decrease it.
“Once we can [settle on how much it costs to make this product] then we start to make those considerations of production costs and how we lower production costs,” Gordon said. “Then efficiency not only is a fancy marketing term, but it becomes an actual necessity for businesses to be able to survive and compete in the market, and we’re not there yet. Until efficiency becomes a necessity, a very small number of people are going to do it.”
Although there are risks and inconsistencies associated with this emerging industry, there can be a home for solar. Many describe the legal cannabis industry as the “Wild West” right now, and it wasn’t too long ago that the solar industry was called the same. Who better to guide the legal cannabis industry into energy efficiency than its partner-in-crime since the beginning?
“[Cannabis] is the only new ag industry to come online since the industrial revolution,” Gordon said. “We now have a giant spotlight on a new agriculture industry with just millions of dollars, endless technology companies, real estate developers, efficiency experts, all of these people looking at this industry. We have an opportunity to reframe sustainability in agriculture. That’s crazy.”