One significant trend in indoor cannabis cultivation is relocating LED drivers from grow spaces to a centralized control space, like an electrical room. This design offers several benefits. Firstly, the heat generated by the drivers is more easily managed in a dry space such as an electrical room than in a warm, humid grow room. Drivers containing active electrical components like capacitors are more prone to failure in warm, humid environments. Centralizing a few large drivers simplifies servicing compared to managing hundreds or thousands of drivers dispersed throughout the facility. Since drivers are not washable, removing them from grow spaces also reduces biosecurity risks. For greenhouses, removing drivers reduces shading and lots of weight, reducing the amount of steel required to build the structure. Lastly, large, centralized drivers benefit from economies of scale compared to smaller drivers attached to LEDs, often significantly reducing the cost of the LED system.
Despite these advantages, few growers have adopted this design because distributing electricity from the remote drivers to the LEDs has historically been too dangerous or costly. Fortunately, Digital ElectricityTM from VoltServer addresses this concern. Below, we explore these benefits more deeply and summarize how Fault Managed Power Systems (FMPS) or Digital Electricity make centralizing drivers straightforward.
Saving Energy by Reducing Heat in Grow Spaces
A common objective is to minimize heat generation within grow areas to improve growing conditions and reduce the load on HVAC systems. Although every little bit helps, growers overestimate the direct energy and HVAC cost savings. Standard LED drivers convert AC from the grid to low-voltage DC power, which LEDs use. Some energy is lost in this conversion as heat. Typically, LED drivers are between 89% and 95% efficient, so they only account for between 5% and 11% of the heat produced by an LED. A standard 1000W LED produces about 3,400 BTUs of heat, with the driver contributing only about 272 BTUs (or 8%), while the LED modules produce the remaining 3,128 BTUs. Regardless of where the driver is located, energy is still required to manage those 272 BTUs. However, HVAC systems operate more efficiently in a dry space like an electrical room than in a humid grow space, so centralizing the drivers could reduce energy use by 3% to 4%.
Why Growers Should Understand the Arrhenius Principle
The Arrhenius equation, a fundamental principle in chemistry, predicts that for every 10°C temperature increase, the electronics’ failure rate doubles. Applying this principle to LED drivers, we find a compelling reason to centralize these components outside the warm, humid grow spaces. By relocating LED drivers to a cool, dry, climate-controlled electrical room, we substantially mitigate the thermal and moisture-induced stress on driver components. Thus, centralizing drivers significantly slows the reactions that lead to the breakdown of electronic components and materials, such as corrosion of metal parts and deterioration of insulation. This not only extends the operational lifespan of the drivers but also reduces maintenance needs and costs, enhancing overall system reliability and efficiency.
Biosecurity Risk
One of the most critical (and often overlooked) risks in the cannabis industry is biosecurity. Long-term profitability depends on regularly washing down rooms thoroughly. Jamie Schurmans, Vice President of EFI Engineering and a former facility and design construction leader at Canopy Growth and InFarms, has observed firsthand that if every part of the grow room isn’t regularly and thoroughly washed, the population of harmful microorganisms will increase, eventually causing declines in yields and quality. For this reason, he advocates for designing facilities to make rooms wash-downable by removing active electrical equipment, like LED drivers, from grow spaces.
The Challenge with High Voltage DC
So why don’t more growers centralize LED drivers? Only recently, installing the necessary infrastructure to distribute electricity hundreds of feet from the remote drivers to the LEDs was extremely costly, complicated, and potentially dangerous. Growers had two options: use remote drivers that converted AC to low voltage DC, which couldn’t be distributed over long distances without significant voltage drop unless very thick, heavy, expensive conductors were used. Alternatively, they could locate many remote drivers close to the LEDs, such as in the hallway or ceiling above the LEDs, but this often made the wiring complex and neutralized the benefits.
The second option was to use DC drivers that converted AC to high-voltage DC (HVDC). This allowed the centralization of all drivers in one location and the distribution of the HVDC over long distances using thinner cables. However, HVDC is more dangerous than high-voltage AC, requiring DC-rated breakers and local disconnects inside the grow space, making installation more expensive. Furthermore, the National Electrical Code mandates GFCIs for LEDs in humid locations like grow rooms, and since GFCIs are not available for DC power, the LEDs had to be hardwired. This required calling in an electrician whenever an LED issue arose or a unit needed to be moved.
Fault Managed Power Systems
The introduction of Fault Managed Power Systems (FMPS) offers a solution that combines the power and distance capabilities of high-voltage DC with the safety and installation ease of low-voltage DC. The recent changes in the National Electrical Code (NEC) have made such systems viable, enabling the centralization of drivers in a fast, easy, and cost-effective manner. Digital Electricity, a form of FMPS developed by VoltServer, is particularly suited for powering horticulture LEDs. This technology is designed to detect any electrical faults, such as short circuits, within milliseconds, shutting off the power before any harm can occur. The system then quickly restores power once the fault clears while also informing the operator of the fault’s location and cause.
Benefits of Digital Electricity™
Digital Electricity™ streamlines electrical distribution in buildings by eliminating up to 75% of the typical equipment required, such as step-down transformers, subpanels, and breakers. Low-voltage technicians can install the entire system in significantly less time. Because the system is intelligent, it removes the need for a separate system to control and monitor the LEDs. The intelligence is embedded within the same cables that distribute the electricity.
This technology dramatically simplifies the removal of drivers and all other active electrical components from grow spaces. Traditional grow room setups contrast sharply with those utilizing centralized LED drivers, which not only enhance system reliability and control but also reduce the costs associated with electrical, control, and LED systems by up to 40%. Moreover, with no active electrical components in the grow spaces, all the Digital Electricity equipment within these areas can be easily washed down, minimizing biosecurity risks.
Summary
The innovative shift in indoor cannabis cultivation towards centralizing LED drivers outside of grow spaces, facilitated by the advent of Fault Managed Power Systems, significantly enhances operational efficiency and safety. This shift reduces construction costs and provides improved growing conditions and a more reliable system, representing a significant opportunity for cannabis growers to improve operational efficiency.
