Cannabis: A budding opportunity for energy savings

April 1, 2019 | 3 min read
Lauren Morlino | Emerging Technologies & Services Manager

Now that it’s legal to grow small amounts of cannabis for personal use in our state, we’re hearing from Vermonters concerned about the impact of indoor growing on their energy bills. We’re hearing the same concern from customers considering greenhouse and warehouse operations in anticipation of a legal commercial cannabis market. Their concerns are well-founded. Since Colorado legalized recreational marijuana in 2012, indoor cannabis growing has accounted for about four percent of electricity demand in Denver alone. Following legalization in Portland, Oregon, seven power outages in six months were attributed to indoor pot cultivation. Whether home-based or on a large commercial scale, indoor growing is energy intensive.

In recent years, to mitigate the impact of this increasing energy demand, researchers throughout the country have turned their attention to indoor growing’s biggest energy hog: Lighting. Hailing from diverse sectors – academia, manufacturing, electric utilities, and the energy efficiency field – these researchers have shared a goal to bring the most efficient, effective grow light to consumers. In March of 2019, that goal was reached, owing to the nation’s first quality standard for low-energy grow lights. Established by Design Lights Consortium (DLC), the standard helps consumers identify high-quality light-emitting diode (LED) grow lights that can provide plants with necessary light with a fraction of the energy of traditional equipment.

What are best practices for efficient indoor growing?

It’s our job to be alert to increasing energy demand in our state, to find solutions, and to make those solutions accessible to Vermonters. In the case of our state’s expected rise in energy demand from indoor growing, we’re sharing efficiency information about an agricultural sector that is still evolving. While we continue to identify and assess efficient indoor growing technologies, we are providing these recommendations to growers:

  1. Take it outside: During Vermont’s growing season, give your indoor growing equipment a break by bringing your plants outside. Vermont law requires cultivation to be in a secured enclosure that’s screened from public view.
  2. Switch to efficient lighting: The traditional go-to grow light has been high-pressure sodium. These lights are high wattage and they run hot, which can increase air conditioning needs. LED grow lights run cooler, last longer, and use about half the energy of traditional grow lights. There are a lot of LED grow lights out there of widely differing quality and energy use. That’s why we’ve started offering a rebate for low-energy LEDs that are top quality for indoor growing.
  3. Insulate your growing space: Too often, growers unknowingly overuse their heaters, cooling equipment, and dehumidifiers because they’re doing battle with outdoor air entering their growing space. A leaky building also allows indoor air to escape – air that growers have paid to keep at optimal temperatures and humidity levels. The solution is to air seal and insulate. Advice and rebates for air sealing and insulation projects are available, whether done by a Home Performance with ENERGY STAR® contractor or a do-it-yourselfer.
  4. Upgrade to efficient cooling and heating equipment: heat pumps deliver cooling and heating with very little energy use.
  5. Use an efficient dehumidifier: Some growers use dehumidifiers to prevent moldT. ENERGY STAR certified dehumidifiers use at least 15% less energy than traditional units. Be sure to get the smallest model needed to avoid unnecessary energy use. Rebates are available.

Legalization of home growing enables us to do our job as energy advisors for indoor growers who have been silently wasting energy and for new growers who want to begin cultivation armed with the facts. As further legislation about cannabis growing moves through Vermont’s Statehouse, we’ll continue to maintain awareness of new energy use implications and associated energy management approaches of benefit to our state.