This post was written by Keith Dawson for UBM Tech’s community Web site All LED Lighting, sponsored by Philips Lumileds. It is archived here for informational purposes only because the All LED Lighting site may go dark at any time. This material is Copyright 2013-2015 by UBM Americas.


LEDs in the Green Rush

There's big money to be made in legalized marijuana, and growers in Colorado and elsewhere are among the most adventuresome experimenters with LED-based horticultural lighting.

Two states, Colorado and Washington, have completely decriminalized marijuana; its possession, medical use, and recreational use are all legal. In 21 more states and the District of Columbia, either its possession or medical use with a doctor's prescription is legal. Liberalization bills have been filed in another dozen states.

LumiGrow Pro650 greenhouse light.

Though federal law still criminalizes possession of marijuana and even "paraphernalia" that enables drug use, the feds have gone easier on enforcement as the legalization movement has grown nationwide. In fact, the US Justice Department said in August that it will not interfere with state legalization, as long as the states keep the drug within their borders and keep it out of the hands of minors.

Wired has a long report on the involvement of Silicon Valley entrepreneurs and investors in the burgeoning legal marijuana scene. Much of the action is in Colorado, which is the nascent industry's crucible -- the state is half a year or more ahead of Washington in building a supply chain and opening retail marijuana stores. Denver alone has 4.5 million square feet (418,000 sqare meters) of warehouse space devoted to marijuana cultivation. Washington just cut back the size and number of approved marijuana growers; the state's call for 2 million square feet of growing space resulted in applications covering 36 million square feet.

Wired reports on the San Francisco Patient and Resource Center (SPARC), which is running an A/B test in which some marijuana is being grown under LED lights from LumiGrow and some is being grown under sodium lights. Preliminary results indicate that the LED illumination may perform better.


A more speculative advantage for LEDs is also being tested at SPARC. Traditionally, growers keep young plants illuminated 24 hours a day and switch to a 12-on-12-off schedule as the plants mature. The simulated night slows the plants' growth, but it also triggers the crucial flowering of buds. A SPARC researcher has figured out that the absence of red light tells the plants it's nighttime. Instead of 12 hours of total darkness, the researchers are supplying 12 hours of blue light only, allowing the plants to continue growing while producing buds. A/B tests of this growing system are being set up now, and results should be published in conjunction with UC Davis this year.

Green rush
Last fall we noted Lighting Science Group's involvement with Denver's legal medical marijuana industry. The news now is that LSG's man in Denver, ex-NASA scientist Neil Yorio, just jumped ship to LSG's large customer there, the medical marijuana grower Denver Relief.

Yorio is not alone in seeking to capitalize on the "ganjapreneur" boom in legal marijuana. reported in January that investors have been flooding into Colorado. A report on the medical marijuana industry claimed it is growing faster than smartphones and will amount to $2.34 billion in 2014. That's only retail sales of marijuana -- the total must be several times as large if we include the growers and suppliers to the industry. These are the modern Green Rush equivalents of the 1849 California Gold Rush suppliers of shovels and pans, which, the conventional wisdom says, were the ones who got rich.

In 2010, CNBC estimated the total potential US retail market for marijuana -- if it were legal everywhere -- at $35 billion to $45 billion. Let's call it $100 billion, including the picks and shovels. LED lights for growing plants must amount to a respectable chunk of that total.

— Keith Dawson Circle me on Google+ Follow me on Twitter Visit my LinkedIn page, Editor-in-Chief, All LED Lighting

Related post: