By Craig Allen
Power! A subject that has mystified growers for decades. Every grower must negotiate the available power, its location compared to the growing space, how to run electrical lines and how to install outlets properly. The scale of I-502 licensed growing operations means the end of “dryer plug” bloom rooms and the beginning of backup generators, thermal overload cutoffs and commercial relays. Pricey professional electrical installations are now the norm, but the benefits are safety and greater capability.
Some producers will have growing facilities with power installed and some will have the opportunity to build out from scratch. If you plan to purchase or lease an existing structure, keep in mind power is expensive to install; try to get a building with as much installed power as possible to save yourself time and money. A project that requires new construction will cost more up front. However, in the long run, it may increase ease and efficiency. Not everyone has the resources necessary to build everything at once, so you should try to build while considering your future expansion plans. You do not want to waste your future profits removing and replacing systems you have already built.
The following is Part II of Marijuana Venture’s three-part series on building a top-notch Tier 3 growing facility.
Electrical needs per room: It is important to plan out the electrical needs for each room in detail. If you plan properly, you can avoid things like an extension cord jungle. In this plan’s design, each room will need different amounts of power and power for different purposes. Some rooms will need a good deal of 120-volt, and others will need dedicated 240-volt sub-panels.
Your cuttings will first be grown in the cloning/transplants room, or “Veg 1.” This room is designed to bathe the young plants in gentle light, allowing them to set their roots. This stage is probably the most important for the future growth of your canopy. Since young plants are very fragile, their growth can be stunted by many factors, including too much light, heat, cold, nutrients, imbalanced pH, etc.
Providing the proper atmosphere for growth during this 10- to 18-day period will ensure that the adult plants are strong enough to produce dense flowers. T5 fixtures are suggested for this room to give the plants that gentle and steady light they will need, and as a general rule T5s run on 120-volt power. However, you will want to install a sub-panel with enough power to handle both the T5s for cuttings and some high-intensity discharge (HID) lights for your mother plants.
After your transplants are rooted, they will make the transition to “Veg 2.” This room will have dimmable 1000-watt HID lights — either metal halides or high-pressure sodium (HPS) bulbs. Metal halide bulbs are generally a good choice at this stage because their light output is about 25 percent less than HPS. This eases the transition for the still-fragile plants as they are moved from T5 lights in Veg 1 to HPS lights in the bloom stage. To encourage this transition even further, we also recommend beginning the Veg 2 stage with dimmed metal halide lights (around 600 watts), then increasing the output to 750 watts or 1000 watts after the first few days. The design shown in this series calls for 144 1000-watt ballasts in Veg 2, so you will need a hearty sub-panel to direct power.
Once the canopy in Veg 2 is lush and healthy, it is time to bloom the crop. In the design shown there are eight bloom rooms, and each bloom has 72 digital 1000-watt ballasts running high-output HPS bulbs. Double-ended HPS bulbs can also be used; they have a slightly higher output (1-2 percent), but have a higher initial cost and are more expensive to maintain.
Blooming your plants with HPS bulbs is drastically more productive than any other lighting type, per watt. Some people will choose to use LED fixtures and other lighting sources to bloom, but they are far more expensive than other fixtures.
Independent tests have demonstrated that no other fixture sold today can match the production output of traditional HPS lighting. That said, HPS bulbs consume a good deal of energy, so each bloom room will need dedicated power.
One way to manage this is to bring power in from the main panel to a sub-panel. This sub-panel will control all equipment — 120-volt and 240-volt — in the bloom room (this includes fans, controllers, dehumidifiers, air conditioners, meters and more). Off of this sub-panel you will want to draw power to a second sub-panel dedicated to your ballasts so that you can ground them separately. Digital ballasts are best installed with a separate ground from the rest of your electrical equipment because the electromagnetic feedback from their operation can render other equipment inaccurate. For example, a nutrient meter can show incorrect readings if the power source it is plugged into has feedback from nearby ballasts. The last thing a grower wants is a false reading on a nutrient meter.
Outside of your growing space, you will need to install work lighting and climate control systems, as well as some generic power outlets for tools and other gear. These needs should be fairly minimal and your electrician can help you find the best way to install those systems.
Tricks of the trade: Commercial growers have discovered some effective ways to save money and protect crops from equipment failure. For example, one of the most important and overlooked safety items in an electrical setup is a thermal power disconnect.
This is installed between your main panel and a sub-panel and it’s controlled by a small thermostat in your grow room. In the event of a climate control failure — for example, if your air conditioner malfunctions but your ballasts are still on — the unit will automatically cut power to the entire system when the room temperature rises above a set amount. This will protect your crop from certain heat damage until you can get your air-conditioning fixed and cool things down.
A backup generator system is another highly recommended piece of equipment. When the power goes out — and it will — you will want to protect your essential systems to ensure that there is no effect on yield. Ideally, the generator could power your entire facility so that there is minimal downtime. But more practically, your generator only needs to handle 10-20 percent of your overall needs. The most important systems are cloning machines, minimal lighting in Veg 1 and Veg 2, minimal lighting in the bloom rooms and minimal HVAC.
Electrical components can be pricey, and one of the most expensive is wire. This is one reason why sub-panels are so prevalent in this design. Running one large wire to a sub-panel 100 feet away from the main panel lets you avoid running 20 smaller lines that same distance. These savings will add up and leave you more money for other parts of your build-out. Once again, if you are planning to expand your facility over the course of a few months or a year, try to wire your space for what it will look like when it is completed; this will make expansion much easier and more cost effective.
Another item which can save strapped-for-cash producers in their initial build-out is a commercial relay that powers two HPS lights with one ballast. This works by switching the output of the ballast from one lamp cord to another lamp cord. So let’s say you have five HPS lights in Bloom Room A, and five HPS lights in Bloom Room B; normally you would need 10 ballasts to power all 10 lights, but you can reduce that number to five ballasts if you install the commercial relays.
Now Bloom A can run five lights for 12 hours, then the power switches from Bloom A to Bloom B and Bloom B has five lights on for 12 hours. There are some prepackaged products on the market called “flip boxes” that allow up to 10 or 20 ballasts to flip between rooms, but they are costly, ranging between $50 and $100 per ballast replaced.
In large commercial installations, it is far less expensive to buy the components and hardwire your ballasts and lamp cords to separate commercial relays which may only cost you $12-15 per ballast replaced. But you do have to wire them yourself, and that takes more time than a plug and play unit.
Wrapping up: This Tier 3 design needs a lot of power, and it will require roughly a 3,000-amp service from your electrical provider. The nuances are not the same as a 200-amp home panel, so it will be important to find a good electrician who is willing to help you discover the best way to apply these methods to your space. Getting the major systems like electrical correctly managed in the beginning will help you build a strong business with good operational flow and product output.
The final story in this series will focus on the general room layouts and the climate of the individual rooms. You now have just enough information in your hands to be dangerous, so bear in mind that you should still discuss your final plans with an experienced growing consultant.
Even if you flesh out only one idea with a good consultant, it will be well worth the money. And if you have general questions, please write to Marijuana Venture and we will do our best to respond to them in our new “Ask the Grower” section. Email your questions to Editor@MarijuanaVenture.com.
Craig Allen is an experienced grower and the co-owner of Groco, a retailer of commercial marijuana gardening equipment and supplies, based in Bellevue, Wash.