By Colin A. Young, State House News Service

BOSTON -- A year ago it might have been taboo for a utility company to set up shop at a conference devoted to marijuana, but no one batted an eye Thursday when a representative from National Grid got up to talk about how his company works with cannabis cultivators.

"I get a lot of snickers when I tell people I work for an electric and gas company and I deal with cannabis," Fran Boucher, National Grid's energy efficiency program manager, said at the World Cannabis Congress and Business Exposition.

National Grid, Eversource, Unitil and other utilities in the state work with marijuana businesses, mostly cultivators who rely on lights to grow their plants, to make such facilities more energy efficient. Boucher said marijuana grow facilities are "just mindblowing energy consumers."

"You could pay $30 to $50 a square foot annually in electric and gas costs to operate the facility and it would not be unreasonable to find out that energy is 50 percent of the cost of the product that you're selling," Boucher said.

Marijuana needs a lot of light to be grown properly for commercial sale -- sometimes as much as 20 hours of direct light every day -- and growers work hard to control the moisture in the growing atmosphere.

Massachusetts has among the highest energy costs in the United States, making establishing a marijuana grow facility here a more expensive proposition than in other states. Commercial and industrial electricity prices in Massachusetts were 43.22 percent and 89.06 percent higher than the national average in June, according to the U.S. Energy Information Administration.

Between lighting, dehumidification and cooling systems to eliminate the heat given off by the lighting, the average grow operation, Boucher said, draws about 400 kW of electricity at its lowest usage -- "believe me, that's a lot of power" -- and as much as 750 kW when running at full steam.

While the average office building uses 0.7 watts of electricity per square foot for lighting, the lighting in a standard "flower room" of a marijuana cultivation center uses 60 watts per square foot, he said.

"The lighting alone here blows away anything you would see anywhere else. These facilities use more energy per square foot than anything other than maybe a few in industrial processing. It blows away hospitals, laboratories...it might be on par with extreme data processing centers, like a Google or a Facebook," Boucher said. "It's a huge load, it's a massive load, and that's why there is a huge opportunity for utilities to help you and for you to reduce your usage and be more energy efficient."

Utility companies can offer incentives for marijuana businesses that design or upgrade their facilities to be more energy efficient, Boucher said.

Available services include engineering to help design an efficient facility and an energy savings cost/benefit analysis. Then, as long as the grower installs the efficient systems and uses them as agreed, the utility company will provide payments proportional to the savings. There is no upper limit to the incentives and projects as small as installing 10 LED lights could be eligible, he said.

Boucher said National Grid began working with cannabis companies about a year ago and currently has about 15 projects in its queue.