“Choosing the LEDs and, in my case, Fluence, was critical to the overall design of my whole facility,” Dow says. “All the other equipment was HVAC-related equipment that was able to be sized smaller and more efficiently. There was really a trickle-down effect throughout the whole facility that was a direct result of choosing LEDs as my light source.”
Massachusetts law requires cannabis cultivators to use no more than 36 kilowatts per square foot of canopy space, which Dow says would be difficult to achieve with high pressure sodium (HPS) lighting, unless cultivators compensated with solar power, for example, to offset their energy use.
Choosing LED lighting during the buildout of its facility was the first step for Solar Cannabis Company to comply with Massachusetts’ strict energy regulations, Dow says. The company now grows three vertical tiers of plants in four operational grow rooms with roughly 200 lights per room.
“It’s almost half the power you’d use for HPS with a much more focused light,” he says, adding that a traditional HPS light uses roughly 1,000 watts whereas an LED fixture uses about 625 watts. While that isn’t quite half of the energy load, Dow says that when Solar Cannabis Company factored in the lower cooling requirements needed for the facility, the team was able to cut its power needs roughly in half with proper design.
“[Using LEDs] was step one, and then that helps to reduce your overall heat load, your electrical profile [and] all your HVAC equipment,” he says. “For us, it started with choosing LEDs and then trickled [down] through the rest of the facility design.”
Beyond complying with the state’s energy rules, Dow ultimately wants Solar Cannabis Company to be carbon-neutral. The company strives to have 50% less emissions than comparably sized operations, he says, adding that his team has “significantly surpassed” this goal.
“We’re hoping by next year, with the use of our combined heat and power units . . . to offset 75% [or more] of our emissions,” Dow says. “We are really excited about it and we’re taking every angle we can to cross into that energy profile and CO2 production.”
Solar Cannabis Company is currently exploring large-scale batteries to capture and use more solar energy on-site, as well as new and more efficient solar panels.
“In the near future we would like to keep more of our solar ‘behind the meter’ by utilizing large battery arrays,” Dow says. “For this to happen, batteries will need to become more attainable and proven reliable for continued, mission-critical operations. Since Solar [Cannabis Company] has no real electric grid backup power (only 500 amps), we always need to balance the decisions we make with our microgrid.”
Dow says the company also aims to modify its chilled water system to utilize the additional waste heat from its combined heat and power (CHP) units, or cogeneration units, by using an absorption chiller, which would further reduce the facility’s energy needs. CHPs are able to generate power on-site via natural gas. By eliminating typical transmission line loss from a traditional power plant, Dow says, Solar Cannabis Company can save over 20% of the power that is lost before the end user.
“There are also other less-obvious optimizations we are continually implementing throughout the facility in order to stabilize our overall load profile,” Dow states. “We try to utilize best practices wherever possible, from water recycling to packaging, and [we] try to keep our team focused on operating efficiently and sustainably.”
Solar Cannabis Company uses Fluence by OSRAM LED fixtures throughout its whole facility. The company’s initial order was for roughly 1,200 lights, Dow says, adding that the team did its due diligence before purchasing the LEDs.
Dow originally wanted ceramic metal halide (CMH) lights for the facility, with plans to retrofit with LEDs when his business was financially ready to do so.
“However, when you really looked at what that entailed for the design of the whole facility and the upsize of the HVAC and all the other equipment costs that go along with that, not to mention the energy profile that goes with those cheaper lights, then LED became the real clear winner, provided you could trust the LED manufacturer,” Dow says.
After almost making a deal with another LED manufacturer that has since gone out of business, Dow partnered with Fluence and received about $400,000 in rebates from his utility company when purchasing the fixtures.
Dow says Fluence’s experts helped the team adjust its environmental parameters to accommodate the LEDs after they were installed, and they have also been available for troubleshooting if any issues arise.
In addition to the energy savings associated with the LED fixtures, Dow says his team has also seen increased yields.
“From the first harvest, we were expecting a really tough sort of learning curve, and actually, [Fluence] definitely helped us with some environmental parameters right when we first started,” Dow says. “You’re feeding these [plants] with such intense lights that you also need to have the fertigation or the nutrients to match. Fluence certainly helped us dial that in from early on. So, right out of the gate, we were expecting a ramping up curve to figure out how to use these lights, but we had a really successful first harvest. I want to say we might not yet have hit 2 pounds per light—we might not have been there yet—but we were certainly inching up that way. Now, we have significantly increased the yields we’re getting out of these lights.”
Dow adds that any apprehensive growers who are considering LEDs should know that there is research to support their efficiency in cannabis production.
“Whereas it was a really scary thing to do five years ago, the science is there, the engineers are in the space and there’s a number of really reputable LED companies out there that are producing a top-rate product that can compete with high pressure sodiums any day of the week,” he says. “The science is there. … It’s the environmentally conscious thing to do, and there’s no downside for crop yields.”
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