In the Weeds of Energy Use: Home marijuana growers in Michigan must follow proper guidelines

Shutterstock / ShooArts / LightSpring
Shutterstock / ShooArts / LightSpring
Published On
May 13, 2022

Residents in Michigan wishing to grow marijuana in their homes—like those living in other states with legalized use—need to learn ahead of time how much energy it demands. They also should know the safety precautions to prevent electrical hazards for their neighbors, and communities as well as themselves and Michigan’s electric grid.

Michigan’s Cannabis Regulatory Agency (CRA) is working in conjunction with some of the state’s major utility companies and other state agencies. It has posted an informational page on its website detailing how homeowners should work with their local utilities and a licensed electrical contractor before embarking on such endeavors—and why preparations are necessary.

“We want to make sure that Michigan residents understand their responsibility to keep their neighbors and their communities safe by exercising proper caution in their home grows and working with their local utility to ensure their electrical service is sized appropriately to serve the increased energy demand,” said Andrew Brisbo, CRA executive director.

It takes an enormous amount of power to grow marijuana plants. A Michigan resident growing 12 plants can increase a home’s energy demand by 2.75 times, according to the agency. Maximizing the 72-plant limit for a medical marijuana caregiver’s residential grow operation could result in energy usage equivalent to the average use of 10.75 houses.

John Banks, president of Motor Shop Electrical Construction Co. Inc., Battle Creek, Mich., knows a thing or two about the types of equipment necessary to grow marijuana and the corresponding electrical hazards. His company works with commercial marijuana growers and provides everything from the primary power for the lighting, temperature, watering and ventilation systems down to the communication system.

All these systems run 24/7, which requires constant scrutiny, because if the system is operating over capacity, the rise in temperature can cause overheating conductors and possible fire.

Andrew Brisbo
Andrew Brisbo

“It’s also a constant drain on the electric grid, requiring a lot more flexibility on the system to provide that kind of capacity,” Banks said. “A lot of people don’t understand. They say they want to grow a few plants in their home, but they’re still taxing the system to the point that—if their equipment hasn’t been properly sized and ready for that kind of load—the danger is imminent.”

For Motor Shop’s commercial grower clients, the company works off drawings that have been run through with engineers and architects, ensuring everything is sized correctly and being done according to code.

“The commercial growers are so sensitive to the problem of power that they have installed backup systems such as stand-alone generators,” Banks said. “One of the facilities that we’ve been dealing with actually worked with their local municipality to bring in a separate substation to feed this operation. Now they’re looking to expand, so we’re going back to the utility to ensure they have constant power and that they’re sizing their generators properly.”

Michigan residents with medical marijuana patient and caregiver registration cards have been able to grow a limited number of marijuana plants in their homes since 2008, according to the CRA. After Michigan voters legalized marijuana in 2018, state residents over the age of 21 have also been allowed to grow up to 12 plants at their home. These developments have resulted in an influx of new residential marijuana grows that have a major impact on Michigan’s electric grid.

Residential marijuana growers need to know the proper steps to take to ensure the safety of themselves and their equipment. Overloading electrical equipment can be a fire hazard, and, if it is damaged, power outages can occur.

Licensed electrical contractors should work with potential customers before starting a home grow; those individuals should become familiar with local rules and ordinances and contact their local utility to ensure their electrical service is sized appropriately to serve the increased energy demand.

“When residential growers work together with their electric company, significant damage can be avoided, including unanticipated significant overloading that can lead to catastrophic failure of utility and customer-owned equipment,” according to the CRA.

John Banks
John Banks

“If a significant customer load is added before the energy provider has an opportunity to review and utility equipment is damaged as a result, the customer causing the issue may be held responsible for associated costs of repair.”

There could also be lengthy delays in the restoration of service. The utility must determine what caused the issue, find out what the true load sizes are and upgrade its equipment to serve it. In addition to damaging the customer’s equipment that added the significant load, there could be possible damage to other customers’ properties that received service from the same transformer. This damage can range from appliances to sensitive electronics, such as smart TVs, computers and more.

The CRA also mentioned that structural “fire dangers are by far the worst-case scenario for marijuana home grows. When circuits are overloaded beyond their rating, it becomes a hazard, and the cost associated with this kind of incident is immeasurable, as it has the potential to cause death in addition to widespread damage to the electrical system and people’s property.”

Consumers Energy was one of the utility companies that was instrumental in developing the informational webpage on the CRA site for residents wishing to grow marijuana in their homes.

“At Consumers Energy, providing safe, reliable energy is our top priority and forms the foundation for everything we do,” said Jeff Mayes, executive director of business customer care at Consumers Energy. “It’s imperative for customers to engage with their energy provider early to ensure the increased load of their grow operation doesn’t damage the transformer serving their home or negatively affect other customers on the electric distribution system.”

Contractors failing to coordinate with their energy provider could cause undue wear on a customer’s equipment and safety issues such as a dangerous fire, Mayes said. Taking these proper steps also ensures there is enough energy for others.

“Without the proper electric equipment in place to sustain an increased demand in electricity, the quality of service could be interrupted for neighbors,” he said. “Picture a slice in a hose that doesn’t allow running water to flow to the end and you get an idea of the effect high energy use without the proper equipment can have downstream.”

Jeff Mayes
Jeff Mayes

Electrical contractors can assist by ensuring that the electric system is set up to handle the grow facility’s needs without disruption, Mayes said. If a utility finds the added load without the customer contacting them and deems it a safety concern, the utility could disconnect the service until proper upgrades are made. This could cause the customer to have lost time and crops and could require them to use generators.

Additionally, the sooner the EC is contacted—before equipment purchase—the better the contractor can help with available rebates on energy-efficient products such as lights and more.

“For instance, discussing with the customer the ability to cycle load to prevent a large swing in electricity demand could lower the need for upgrades,” Mayes said. “Upfront discussions are also important to prevent surprises on equipment location and any potential upgrades that may be the responsibility of the customer to pay.”

The electrical contractor will assist with internal wiring needed and proper sizing of the meter and service connection, he said. If this is not done, it could cause the meter and wires to overheat and potentially catch fire.

The utility sizes equipment up to the meter based on information provided by the customer, Mayes said. The electrical contractor will ensure all panels, wiring and equipment is sized properly to ensure there are no safety concerns that could lead to fires, extended outages or lost crops.

In states where home or commercial marijuana is legal, electrical contractors should learn about the needs and requirements that support such an operation. It’s inevitable that these calls will come in.

About the Author

Katie Kuehner-Hebert

Katie Kuehner-Hebert has more than three decades of experience writing about the construction industry, and her articles have been featured in the Associated General Contractor’s Constructor magazine, the American Fence Association’s Fencepost, the...

Stay Informed Join our Newsletter

Having trouble finding time to sit down with the latest issue of
ELECTRICAL CONTRACTOR? Don't worry, we'll come to you.