Why Do Growers Choose HPS Rather than LED?
-By Alvis from Grow Spec
HPS has been applied to planting for decades. Although there have been many people using high-power LED lamps to grow plants since the advent of LED, most people consider HPS as the best choice. The reasons are as follows:
1. Decision-making Process
Growers generally have more say in whether to replace HPS with LED. If growers have not tried LED before, and the successful experience of planting all comes from HPS, then they generally dare not turn to a new light source. After all, plants are of great value. It will not be a big deal if the yield is not increased, but it will cost an arm and a leg if you screw it up. As far as I am concerned, this should be the main reason.
2. Remaining issues in the development history of LED lamps
In the early years when LED lamps were used in plants, there were many issues, including but not limited to:
（1）In the early years, since the driving efficiency and the lamp bead efficiency ( the whole lamp efficiency was less than 1.3µmol/j) were low, and the high-quality HPS usually had the efficiency of over 1.7µmol/j, it was not hard to see that LED consumed more power.
（2）In the case of low efficiency of LED lamps, it was said that low-power LED could be used instead of high-power HPS, which resulted in insufficient PPF (µmol/s) by the whole lamp. However, plants cannot grow well unless they absorb enough light.
（3）Three years ago, there were not many sophisticated manufacturers capable of producing high-power LED drives, which led to the poor function of plant LED lamps: unable to turn on the lights, flicker, etc.
3. Power labeling issues
Many suppliers label low-power LED as high-power LED. For example, they claim that LEDs of 1150W can be replaced with LEDs of 600W, so they label LEDs of 600W as LEDs of 1150W, misleading buyers
4. Without a perfect substitute
Based on traditional planting experience, HPSs of around 1150W will be used to plant 5’X5’ or 4’X6’ areas. However, few LEDs had the same PPF as 1150W in the past, so they could not achieve good planting effects.
5. Different mounting requirements
As a cold light source, the height of LED lamps should be lower than that of HPS lamps, which is a hot light source. However, due to light distribution requirements, the problem is not as simple as it appears. I will discuss it further in following articles.
Is LED unsuitable for planting? Of course NOT! As a more efficient light source, LED can customize the spectrum according to plant varieties, as well as their growth characteristics. In this way, LED is more suitable for planting. Please keep following our next topic "Which One is the Future of Plant Light -- HPS or LED?".