SOMERSET — Growing marijuana, an energy-intensive activity, is not easy to take “off the grid.” Yet that is what Solar Therapeutics is planning to do.

This month the marijuana cultivation and retail company will turn on its microgrid, essentially giving Solar Therapeutics its own power plant, which will generate all the energy required to power its 42,000-square-foot marijuana grow facility. Part of the company’s core mission is to grow marijuana in the most energy-efficient way possible.

CEO Edward Dow said he is not aware of any other licensed commercial marijuana company that generates all its own power.

Dow, a former engineer at Woods Hole Oceanographic Institute, said he thinks the time is right, given growing concerns about environmental sustainability and limiting carbon dioxide emissions. The model also makes financial sense, he said, since higher up-front costs will be recouped through lower energy bills.

“Building sustainably makes sense not just for optics, but as an investment,” Dow said.

Massachusetts legalized marijuana at the same time the state is working toward reducing its greenhouse gas emissions. Marijuana cultivation is generally energy-intensive, since growing indoors requires a lot of light, which generates heat, and temperature and humidity must be strictly controlled to avoid mold.

The state Cannabis Control Commission has established some of the country’s strictest regulations to encourage energy efficiency by growers. As a result, companies are experimenting with everything from LED lighting to systems that recapture and reuse water.

“Because climate change is so pressing an issue, I think as other states look to legalize cannabis for medical or adult use purposes and look at indoor cultivation as a way to cultivate, they are going to have to look at what the impacts will be,” said Cannabis Control Commissioner Kay Doyle, who has led the commission’s energy policy efforts.

Doyle said the commission has worked with the state Executive Office of Energy and Environmental Affairs to create requirements for energy efficiency that also give businesses some flexibility in how to comply.

Part of the microgrid at Solar Therapeutics. The company is generating its own power through a natural gas cogeneration facility. (Courtesy Solar Therapeutics)

In 2018, Massachusetts became the first state to set a specific standard for lighting, requiring large cultivators not to exceed 36 watts per square foot and small growers not to exceed 50 watts. Illinois has since imposed a similar standard.

Jonathan Napoli, founder of marijuana consulting business CannAssist and of a hydroponic garden store, said a typical grower would use 50 or 60 watts per square foot. “It really makes us grow in an energy-efficient manner in Massachusetts,” he said.

In 2019, the state began letting growers meet that requirement by picking from a list of qualified products, rated by the Design Lights Consortium. It also let growers bypass the requirement if they generate at least 80% of their energy from a renewable source, like solar or wind.

Beginning this year, on a time frame that is still being worked out, growers will have to submit energy efficiency plans and data reports regarding their energy usage as part of the application and renewal processes. Some medical marijuana facilities that were operating before the guidelines were written will have extra time to comply.

According to a draft of energy and environmental guidance being considered by the Cannabis Control Commission, growers must identify energy use reduction opportunities; consider opportunities for renewable energy generation; develop strategies to reduce electricity demand; and take advantage of energy efficiency programs. This could include things like using energy-efficient lights or heating, ventilation and air conditioning systems, or building solar panels or wind turbines.

Doyle said commissioners, in reviewing energy plans, will be looking at lighting and HVAC systems, since those consume the most energy, as well as broader environmental issues like water usage and plans for recycling packaging. The commission is publishing specific guidance for businesses.

“We really want to make sure that the businesses have all the information they can to comply in a way that makes sense for them and for the commonwealth as a whole so we can meet our Global Warming Solutions Act goals,” Doyle said, referring to the law that requires the state to reduce its carbon emissions.

Solar Therapeutics is unique in the scale of what it is building. It has its own natural gas cogeneration facility, which uses natural gas to make energy, then uses the “waste” heat that is produced to heat the building. A “free cooling” system uses cold air from the atmosphere to cool the building.

The company has approximately 70,000 square feet of solar panels on its roof and four acres of solar panels behind the building. Battery storage helps ensure the system remains stable.

Lighting is produced using energy-efficient LEDs. Of 10,000 gallons of water used to water the plants each day, a piping system recaptures and reuses at least 9,000 gallons.

Dow said Solar Therapeutics will be able to more than halve its energy use compared to a typical grow facility of that size, and will cut its monthly electricity costs in half. Solar Therapeutics will be able to generate over 5.5 megawatts of power through its microgrid — or enough to power 5,500 houses.

Another company billing itself as environmentally sustainable is Ecofarm in Leicester, which is building a 100,000-square-foot facility, with 55,000 square feet of cultivation space. Ecofarm plans to generate over half its electrical demand through solar arrays and a combined heat and power system, and use other technology like LED lighting and efficient HVAC systems.

Napoli said he urges his clients to consider LEDs, which are more expensive up front but more energy-efficient in the long term. He also recommends systems that can recapture wastewater. After marijuana plants are watered, they transpire water, and growers must pull that humidity out of the air. There are systems that can recapture that water, filter it and use it to water the plants again.

There are efficient chillers and boilers that can be used, Napoli said, and technologies that capture excess heat from flowering rooms and use it to heat and cool the building. Companies can use solar panels or contract with outside solar farms for energy.

A growing room at Solar Therapeutics. (Courtesy Solar Therapeutics)

Sam Milton, an energy and cannabis consultant who recently moved from Massachusetts to Maine, said Massachusetts regulators have tried hard to reduce energy consumption by the cannabis industry. “It’s a fairly new industry, an energy-intensive industry where the rules weren’t even written. They saw it as an opportunity to make their mark and improve the industry,” he said.

At the same time, Milton said, “The market wasn’t quite ready for where the state wanted cultivators to go,” and some cultivators have struggled to determine how to comply with the rules.

Milton said he urges clients to take a “holistic perspective” on how their facilities work, from the building envelope to lighting to technologies like combined heat and power.

Liquid chillers at Solar Therapeutics, which use air from the atmosphere to cool the facility. (Shira Schoenberg / The Republican)

Massachusetts’ strict rules have also attracted the attention of eco-friendly businesses from out of state looking to get a foothold here.

The Colorado-based Sana Packaging, which uses hemp and reclaimed ocean plastic, has several Massachusetts customers, even though its packaging is more expensive than typical plastic containers.

“Knowing that packaging in this industry is going to continue to play a large impact in the environment ... why not use the opportunity now to integrate the cost of sustainability into the cost of doing businesses right from the get-go and know you can create a business model that will not be as damaging to the environment?” said CEO Ron Basak-Smith.

Quentin Veit, technical director of the Colorado-based EasyRoots, which makes HVAC systems for indoor grow facilities, said the company’s focus is on energy efficiency, with different systems available for hot and cold climates. It uses things like utility rebates and tax incentives to reduce startup costs.

In a cold climate like Massachusetts, Veit said, a system can take the heat generated from lighting during indoor cultivation and use it to heat offices or retail space.

Veit said he started his company after seeing the enormous demand on the electric grid when Colorado legalized marijuana cultivation. Given Colorado’s experience, he said, Massachusetts regulators were wise to write regulations to limit power consumption.

“That’s one they probably got right, especially considering Massachusetts has a lot of older electric infrastructure in power generation and distribution,” Veit said.