When considering a grow lighting system it’s easy to get bogged down in technical details, but at the heart of the matter there really are only 3 key elements, namely cost, spectral wavelength cover and light intensity. So let’s break each of these down and also examine what modern LED systems have to offer.
Intensity of light is basically brightness. Yes, the grow light industry likes to witter on about penetrative power, photosynthetic photon flux density and micromoles per square meter, but strip the fancy jargon away and you’re just talking about how much light gets delivered to the plants.
LED grow light panels are much better than HID lamps for your plants. HID (high intensity discharge) lamps, heat up and may scorch the plant if placed too close. One-watt high intensity LED lights on the other hand do not emit very much heat, and can be placed within six inches of your plants. This allows for more flexible positioning of your plants.
What many people find surprising about LED grow light systems is that they don’t generally utilize the brighter lamps that consume from 3 to 7 watts, but are predominantly based on high brightness 1 watt 10mm LEDs. The simple fact is that unlike conventional lighting, LEDs are less efficient at higher loads; this means that whereas 3 x 1 watt lamps may produce say 50 lumens of light, a 1 x 3 watt lamp may only just reach 90 lumens (not 150 as many might suppose).
When it comes to spectral coverage, HIDs fall down badly. Some 65% of their light falls totally outside the Photosynthetically Active Radiation (PAR) zone, meaning it is of no use whatever to plants and to put it bluntly totally wasted. Even the light that falls within the PAR makes a poor job of targeting the chlorophyll absorption peaks crucial to photosynthesis.
LED grow lights, however, are made to target the specific wavelengths in the spectrum where photosynthesis occurs. These are mostly the blue to violet and the orange to red sections of the spectrum, but exclude the green and yellow portions. This means that a LED grow lamp is more effective where plant photosynthesis is concerned.
It’s all very well being technologically the best solution, but what about cost? Well as it happens LED wins again on this count. They are typically more expensive to purchase, but where they really score is longevity and running costs. LEDs last easily twenty times longer (no more replacing bulbs every year or two at best) and consume about one tenth the electricity of HID lamps.
When comparing the differences between the spectral coverage, the intensity, and cost, it is clear to see LED systems are the best choice. Not only will you have a more competent system that will make your plants grow better, but you will also save money over time with it. The only thought you should have is to be certain to choose one-watt bulb systems of high quality in order to be sure you get the best system.
For much more on this subject I recommend these additional articles that explore further into LED grow light panels and how grow lights work.