Artificial Grow Lights
In this article we like to take you through a journey in time with respect to the history of growlights. We live in exiting times with HPS, being the high power dominant light in growing until halfway 2018. However, LED growlights have been knocking on the door since the mid-00’s of the 21st century. How did we get here and where will the next developments take us?
How did we get here? A brief history of artificial (grow) lights
“… let there be light: and there was light.”
Are the famous words passed on for centuries that signal the start of our existence, according to some. On the other hand, the big bang is presumed to have been quite a light-show on it’s own, according to others.
Whichever version of the grand start of life people hold for truth, light was somehow involved. Light seems to be the general catalyst that gets important stuff started.
The first humans that harnessed fire, were suddenly capable to walk through the night and stay safe from wild animals as well as cook food and keep their caves warm. This gave them a huge competitive advantage compared to other species and has allowed these primitive humans to evolve much faster than anything in the world. It shows that our obsession with light has not faded throughout all these years.
For a long time, we humans did not come up with any extraordinary innovations on this useful tool called “fire”. We tested it on various dead (and probably some less dead) items to see what burned better, until we discovered that oil and wood combined produce the best torches. Together with the sun and the moon, this was the most important source of light for humans for a few hundreds of thousands of years. Not until the start of the 1800s, when the first experiments started that would lead into electrical light in the form of lightbulbs. It would take another century from the first successful experiments to the patenting of the first carbon filament lightbulb by Thomas Edison in 1879. By having a nearly perfect vacuum in a glass bulb, the first lightbulbs were able to provide light for around 1200 hours.
In the same era, experiments were being conducted with glass tubes where the vacuum was filled with all kinds of inert gases such as mercury, neon, argon etc. under very high pressure. A current was then run through these tubes to ignite the gases and they would emit light. At first these lights did not have the right spectrums to be very useful; for example, all blue, all pink, all yellow (low pressure sodium). The lamps did not have long lifespans. The inventors were still optimising ways to stabilise the current flow and new electrical parts were being more and more mass-produced.
Fluorescent Tubes and Neon Signs
The developments followed each other rapidly and ran together with the fast modernisation of the world. The colourful tubes found their ways into new industries, such as Neon-signage, which boomed in the twenties and thirties. By the end of the thirties, the large corporation GE, started mass-producing fluorescent lights. By 1951, the majority of lights in the USA was produced by fluorescent tubes then with the classic lightbulb.
In the mid 20th century, there were some developments in the industry; in the UK, the US and the Netherlands, companies started mass-production because they found a way to increase the pressure of Sodium inside a glass bulb so that the electrical parts would not corrode. By increasing the pressure inside the bulb, they were able to increase the spectrum from 589nm (yellow) to some more red, orange and even turquoise. Finally, by adding Mercury and Xenon, the modern day HPS-light was born and it’s use in greenhouses all over the world increased the number of plant-grow-cycles that could be undertaken each year.
Meanwhile in 1927, a Russian inventor reported the creation of the first working light emitting diode. He was investigating semi-conductor technology and noticed that a green spark of light emitted each time he ran a current through carborundum (silica carbide). Fast forward to the sixties, many experiments with semi-conducting materials further, LED’s were starting to be mass-produced as indicator lights for all kinds of home-appliances. The only colours that could be produced at this time were infra-reds (remote controls for TV’s) and red.
LED Grow lights
The costs of one LED were very high and could reach $200 each easily. Another 20 years later, CREE was the first company to patent a blue LED and another 4 years later, Japanese scientists found ways to make high-power blue LED’s, which could then be used in for example Blu-ray DVD-players. The combination of Blue and Red LED’s also gave rise to the first LED grow lights. Lacking the power and cost-efficiency of HPS lights, it would take another 10-15 years until 2014 when it became technically much easier to produce white light emitting LED’s with much higher power efficiencies.
Now, in the early 20’s of the 21st century, almost 100 years after the first report of a light emitting diode, LED’s are going to shape the future of growlights, as well as home-lighting. The power savings with respect to other light sources are the main driver for this changeover. Developments are most likely going to focus on achieving even higher energy efficiencies. A second development fork will focus on getting the costs even lower, even though the costs are currently more then 2.500 times cheaper than they were in the 1970’s, we expect more LED’s in more low-cost applications. Finally, the quality of output will improve; we already see that white-light / all-round LED’s are becoming more powerful and useful for grow lights.
The Future of LED Growlight
Already there are LED-chips on the market that can actually mimic a true sunlight spectrum including UV’s and more green than anything on the market. For example, the Firefly LED-fixture uses this kind of chip which proves to be the next standard in growing. Which directions will developments go after the next 5-10 years? Ask us again in 100 years and we’ll tell you how the story unfolded…