Dive Brief:

• Some 45% of the growth in Denver's power growth is coming from its booming legal marijuana industry, the Denver Post reports, and city officials are concerned the uptick in electricity use will make it difficult for the city to meet climate change targets. 
• Denver officials said last week at a forum on energy use that the nearly 200 million kWh of electricity used by the marijuana industry presents a new efficiency challenge as the city aims to cap energy use at 2012 levels. City energy staffers appealed to a U.S. Department of Energy undersecretary at the forum for assistance in adopting new technologies and practices to compensate for the rise in power demand.
• As about half of the country has legalized medical marijuana and a handful have signed off on recreational use, the large power demands of the industry have begun to tax power grids around the nation. In turn, some municipalities are taxing back — Boulder County, Colorado, last year began charging pot growers an additional 2.16 cents/kWh to help offset greenhouse gas emissions. 

Dive Insight:

Denver officials are concerned that the state's booming marijuana industry will hamper its efforts to meet city efficiency goals and Clean Power Plan mandates. At a forum last week with Department of Energy staff aimed at addressing the city's electricity needs and how they can fit in with greenhouse gas reduction goals, some surprising figures were released.

The Denver Post reports that almost half of the city's growth in power demand is coming from marijuana growers. While increased population has been responsible for most of Denver's 1.2% annual power demand growth, roughly 45% of it comes from pot growing facilities. 

And the latest data from the city's largest utility, Xcel Energy, shows across the state grow houses are burning up to 200 million kWh of electricity a year. The bulk of those are in Denver, and the city believes they used roughly 121 million KWh 2013 — a significant jump from the 86 million KWh used the year before.

The growth of legal marijuana, medical and recreational, has some states worried about how it will impact carbon reduction plans. Denver is considering efficiency measures aimed at pot growers, as the intense lights needed to stimulate growth in turn require air conditioning and dehumidifiers. Grow operations require about 360 kWh per 25 square feet of space by some estimates.

The Northwest Power and Conservation Council has estimated the power needed to grow four plants is about the same as what is needed to power 29 refrigerators.