Mills looked at energy consumption within the cannabis industry, and found that indoor pot production uses about $6 billion worth of energy annually, or enough electricity to power two million average-sized homes. That accounts for one percent of total national energy usage, and spews as much greenhouse gases as three million cars.

But LEDs could be changing that:

Cary Mitchell, a horticulture professor at Purdue University whose heading up a $5 million project to audit and improve LED lighting capabilities in America’s “specialty crop” (see: greenhouse grown fruits, vegetables, nursery plants, etc.) industry, thinks mainstream commercial agriculture has a lot to learn from the pot industry’s gradual embrace of LED tech. He tells the Guardian that specialty crops net about $50 billion a year, and that their growers are seeking out ways to slash energy costs while increasing yields, much like cannabis farmers.

“They’ve undoubtably been doing this for years and years,” Mitchell explains, referring to pot grower’s LED usage. “Since they don’t publish their research, we don’t really know how far they’ve taken the optimization. They probably are ahead of the specialty crop commercial production industry.”

Earlier Dish on marijuana’s environmental impact here.