Dude. This might harsh your mellow.

About $5 billion in power is used each year in the U.S. to grow cannabis indoors, according to a recent report.

Put another way, 20 terawatt-hours per year, one percent of national electricity consumption, or the output of seven large power plants is devoted to make Pink Floyd sound interesting and keep the Denny's graveyard shift in business.

In contrast, data centers consume about two percent of the nation's electric power.

These figures some from a just-released report from the consulting firm of Spicoli, Marley, Chong and Marin.

Just kidding. The report is from a reputable source; Evan Mills, the author, has worked as an energy and environmental systems analyst since the early 1980s. His specialties are energy efficiency in buildings and industry and the intersection of energy technology, global climate change impacts, and risk management.

Dr. Mills is currently with the Lawrence Berkeley National Laboratory (University of California). He collaborated for many years at LBNL with Art Rosenfeld, serving as his Deputy Director of the Center for Building Science, later leading the Center. Dr. Mills is a member of the international body of scientists which has worked over the past two decades under the Intergovernmental Panel on Climate Change (IPCC).

California voters legalized medical marijuana in 1996 and since then, growing marijuana in California has become even more lucrative than when pot was used for non-medicinal purposes. According to AlterNet,The street value of the state’s crop was roughly $14 billion in 2008. A pound of marijuana buds sells for roughly $3,000 at medical marijuana dispensaries. A significant portion is grown indoors under high intensity lighting.

According to the report: "Driving the large energy requirements of indoor production facilities are lighting levels matching those found in hospital operating rooms (500 times greater than recommended for reading) and 30 hourly air changes (6 times the rate in high-tech laboratories, and 60 times the rate in a modern home). Resulting electricity intensities are 200 watts per square foot, which is on a par with modern datacenters."

One of the many fun facts in the report is that one cannabis cigarette has the greenhouse gas impact of driving 15 miles in a 44-mile-per-gallon car.

The report goes on to say: "Current indoor cannabis production and distribution practices result in prodigious energy use, costs, and greenhouse-gas pollution. The hidden growth of electricity demand in this sector confounds energy forecasts and obscures savings from energy efficiency programs and policies. More in-depth analysis and greater transparency in the energy impacts of this practice could improve decision-making by policymakers and consumers alike."

Aside from 1) Just saying "no" or 2) adding another target market for OPower or Tendril, what can be done here?

I'm sure there's a policy lever here -- if marijuana was completely decriminalized, prices would drop and the profit margin would diminish, but that might not translate into less usage.

The obvious answer is replacing the current metal halide (MH) and high-pressure sodium (HPS) lights with more efficient solid-state LED lighting. This LED grow light site claims reductions in electricity usage of 40 percent to 75 percent compared MH or HPS lights. However, other sites in the indoor grow community have some reservations over the effectiveness of LEDs.



