[W]ith interest in cannabis cultivation at an all-time high, Efficiency Vermont has been getting a lot of questions lately about the best ways to nurture indoor plants.
Mimicking the effects of the sun is an energy-intensive business. Growing cannabis or other plants indoors uses about 10 times as much energy per square foot as a typical office building, according to the Southwest Energy Efficiency Project, or SEEP, a public interest organization in several western states.
Efficiency Vermont is trying to distance itself from the public policy conversation about cannabis while preparing for a growth in the energy-draining business.
“We have seen a crazy amount of energy come onto the grid in other states” that legalized marijuana, said Lauren Morlino, Efficiency Vermont’s emerging technologies and services manager. “It doesn’t matter what they are growing; it is more about the energy that it is using. It would be irresponsible for us to ignore the amount of people and businesses that are growing inside, and that really ranges from seed starters with tomatoes and peppers to basil on your countertop for fresh herbs to homegrown both recreational and medical cannabis.”
Vermont lawmakers are considering legislation that would allow for commercial growth and cultivation of marijuana. A law enacted last year legalized adult possession of marijuana, allowing for small scale home cultivation. Households can possess up to two mature plants and two young plants.
If recreational commercial marijuana growth is legalized, state policymakers expect much of the cultivation to happen in greenhouses and buildings. Vermont’s growing season is short, and with artificial lighting and heat, growers can realize much bigger yields indoors than they can outdoors.
With legalization on the horizon, Efficiency Vermont is scheduling events to talk to suppliers and growers about energy efficiency. It also plans to post energy efficiency blogs and offer incentives for things like greenhouse envelope work and dehumidification, HVAC, and lighting. Its engineers have fielded many questions lately about the best lighting for indoor growing.
“Lighting for plants is very, very complicated and very different from the lighting for humans,” Morlino said.
The best time to establish energy efficient practices is before grow operations are established, according to the SEEP report.
“The nature of the market has not been conducive to energy-efficient practices,” the report said. “When marijuana is first legalized in a state, new entrepreneurs tend to rush into the market. Most new operations (especially the smaller- and medium-size ones) start out by leasing empty warehouse space and setting up the equipment using a ‘quick and dirty’ approach, that is, by using simple, trusted technologies with low-initial equipment cost. As a result, they miss many energy efficiency opportunities in the areas of lighting, cooling, and dehumidification.”
The Massachusetts Department of Energy Resources last week published a white paper called Cannabis Energy Overview and Recommendations that assesses the impact of that state’s cannabis industry on emissions. The report said in 2014, Denver saw electricity use increase 1.2 percent, almost half of that because of cannabis, and Washington and Oregon saw similar increases. Nearly 4 percent of Denver’s energy use is now devoted to the marijuana industry, the report said.
The report estimated that a 1 million-square-foot grow facility would use about 14.4 million kWh of electricity.
Farmers in Vermont have always used greenhouses to extend the growing season, and there are many people who grow crops and herbs indoors. Efficiency Vermont, which was established 19 years ago to help Vermont residents, businesses and communities save energy, regularly works with farmers. It provides technical assistance, classes, grants and loans.
Many Vermont farmers who are growing cannabis right now are growing hemp, a low-THC cannabis strain that is produced for a range of uses, including for CBD, a cannabinoid that is widely believed to have healing properties. Many hemp growers start their seeds indoors, and some will keep their hemp plants indoors for the entire growing cycle. While much hemp is grown in fields, some people grow hemp indoors in order to isolate certain strains or wellness effects, Morlino said. “Some of this is super-duper scientific; they don’t want it to be outdoors because they can’t control it as much,” she said.
Grower Lorin Royer of Eden is setting up a 40-foot-long greenhouse this spring on his 11 acres. With the right lighting and heat, he said, some growers can get in two or even three harvests a year.
“If you look at the medical dispensaries in Vermont, the five that are up and running, they’re all indoor,” he said.
Herrick Fox, who recently leased 13,000 feet of greenhouse space in Morrisville to grow cannabis for CBD, said he will grow both inside and outside. He is working with a California company to create a liquid-cooled LED system that is efficient and will return about half of the lighting wattage as heat.
“It allows us to create a precise growing environment, and that’s important for us because we want to achieve levels of consistency and control,” said Fox, a former forester who worked for the USDA. “We can make minor adjustments to achieve desired results in the product, and repeat that from crop to crop.”
It is too early to say what kind of growing operations will form if the Legislature authorizes the commercial production and sale of marijuana. Mike Sullivan, the general manager of Hardwick Electric, said his utility is prepared. Hardwick Electric only has one hemp industry customer now, a very recent arrival, who plans to start plants in a greenhouse and dry hemp in a large barn. Sullivan doesn’t expect much of an impact on power use.
Molino said growing operations that are fully indoors use much more power than greenhouses.
“Greenhouses are heavy users, but not something new to Vermont,” she said. Among other things, Efficiency Vermont plans to offer rebates for high-end LED grow lights that can cost $800 to $1,400 per fixture.
“There’s a lot that can be learned from new technologies,” she said.
