Modern cannabis cultivators are afforded many options for delivering high-quality lighting to their plants. Old bulb technologies, most notably incandescent and fluorescent, have been replaced by more economical solutions that produce greater yields per watt. Among these, High Pressure Sodium (HPS) is believed by many growers to offer the most compelling balance between price, performance, and carbon footprint.
“I know people who use only HPS. They swear that it is the only light you need,” said Joe Nicholson, a third-generation cannabis cultivator in Las Vegas with 48 years of gardening experience.
HPS is one of the most popular lighting technologies used by cannabis cultivators for a variety of reasons. For family farmers and commercial growers, the fact that HPS offers better yields than both metal halide (MH) and leading edge (but expensive) Light Emitting Ceramic (LEC) models makes it a serious contender for their dollars.
“I know people who use only HPS. They swear that it is the only light you need.” — Joe Nicholson, third-generation cannabis cultivator
True plant growth is driven not only by lumens, but also by Photosynthetically Active Radiation (PAR). HPS tech offers significantly greater PAR than competing bulb technologies (such as MH).
However, for those who want to compare lighting options in terms of lumens, the crown again goes to HPS. A 1,000-watt MH bulb will produce 80,000-110,000 lumens. The same 1,000-watt bulb—in the guise of an HPS model consuming the same amount of electricity—produces 130,000-155,000 lumens.
Best Photons Per Watt
Academic researchers are beginning to contribute to the dialog of what constitutes the best lighting technology. In 2014, Professor Bruce Bugbee at Utah State University published a paper that dispelled the urban legend that MH lights are better for vegetative growth and HPS are most suited for the flowering stage of a plant like cannabis.
High Pressure Sodium (HPS) is believed by many growers to offer the most compelling balance between price, performance, and carbon footprint.
“There is no theoretical or empirical evidence to support that claim,” said Bugbee during an interview. “The apparent MH effect is likely caused by the amount of light, rather than the color of light.”
Bugbee’s research supports the widely held perception that HPS offers the best bang for the buck in terms of producing more photons per watt than MH bulbs.
Double the Efficiency
Many in the cannabis cultivation community are sensitive to their carbon footprint. According to a white paper written by Susan Harder, “HPS provides better quality lighting at a lower cost and with less damage to the environment. Metal halide is much less efficient than HPS—MH produces much less light per watt.”
Because they also feature a longer lifespan than MH tech, HPS bulbs are a more prudent investment for commercial cultivators and result in fewer spent bulbs populating landfills. Overall, HPS offers cannabis cultivators one of the most compelling mixes of efficiency, performance, environmental stewardship, and reasonable cost.