With cannabis legalization gaining traction in the states, indoor growing operations are increasing — and with them, the need for innovative and efficient energy solutions.
Hawthorne Gardening Company, a CSG Associate and Leadership Circle member, is a full suite provider for indoor agriculture operations. During an Innovation Classroom presented by Hawthorne Gardening on Friday, consultant Bob Gunn walked participants through some of the energy issues face by indoor cannabis growing operations.
Growing plants indoors is farming, but Gunn argued that, in some ways, it can be compared to a manufacturing process. Lighting is the primary input, and the process also involves HVAC, dehumidification, water usage, airflow and more.
Gunn said the benefits of growing cannabis indoors include precision and consistency, less water use (up to a 95% reduction compared to other methods), security, and proximity to market.
Lighting is about half the energy use of these facilities. Air conditioning is used to cool the environment, but it also cools waste heat from the lights. Dehumidification is used to control evaporation and create air movement and avoid hot spots. Nutrients are administered by water, and plants are grown in tables or racks.
Lighting options include high pressure sodium, ceramic metal halide, and light emitting diodes (LEDs). LEDs are the most energy-efficient option, and the fastest-growing category of indoor agriculture lights. Their light spectrum, control of which is essential for plant growth, can be easily adjusted by wavelength to select for vegetation growth or flowering. Additionally, they have low radiant heat.
Gunn also offered considerations for policy makers. In his view, premature regulation is “a race to the bottom,” and can potentially incentivize growers to stay in the illegal market rather than the regulated market. This has environmental impacts. “Regulated markets will use resources more responsibly,” he said. He also noted that the industry faces a data vacuum.
“What I’d ask of regulators at every level — local, federal, municipal — is to collect data,” he said. “I’d encourage energy disclosures in lighting fixture inventories. Before we tell people what they can use, let’s ask them what they are using. Let’s identify outliers and bring everybody up to speed.”