James Prietzel, Product Manager at Intelligent LED Solutions (ILS)
James is the ILS Product Manager for everything related to LEDs and has been with ILS since 2012. He is dedicated to understanding the latest technologies and innovations from leading suppliers in the OptoElectronics world, from optics, to LEDs and to Intelligent LED Drivers.
Indoor farms can be expense to set up and run. So, for many growers finding the most cost-effective way to do so is vital. High Pressure sodium lamps (HPS) have been a popular solution in horticultural lighting for years; a way to increase yields without a drastic upfront cost. Yet HPS is now being superseded by LED solutions.
So why is this? Let us find out…
The main benefit of HPS over LEDs (Light Emitting Diodes) has always been cost. Typically, HPS have been the cheaper solution to initially purchase and install. However, LED costs have come down in recent years and LED grow lights are now readily available to home growers as well as industrial growers.
Although LED solutions can be more costly to initially purchase, they more than make up for this with their low ongoing costs and lengthy lifetimes. In comparison to HPS lamps, LED grow lights typically offer at least 50,000 hours of sustained light, and in some cases even up to 100,000 hours. Which could mean up to 15 years of quality indoor growing! Whereas a typically HPS lamp system has a lifetime of more like 10,000 hours. So longer LED lifetimes reduce costs from having to more frequently replace fixtures.
Additionally, over this lifetime, LEDs do not have a reduction in their efficiency, so energy costs are also saved, whilst efficiency remains maximised. HPS may be cheaper to purchase up front, but they have higher running costs due to lower efficiency. Modern LED grow lights are often twice as efficient than traditional HPS lamps. So, whilst producing the same yield, electricity consumption could be reduced by up to 50%. Meaning that be utilising LED grow lights, growers may see a quicker return on the initial investment.
But what about performance?
Well, LEDs emit minimal heat. Thermal management through grow light design and heatsinking means that the minimal heat produced is drawn away and dispersed. Rather than with HPS lamps, whereby a substantial amount of heat is emitted directly from bulb on to plants. Therefore, when implementing HPS solutions, adequate airflow and ventilation is essential to successful growing. Which brings its own challenges and costs such as those from running additional HVAC systems. With the steadily low heat emission from LEDs, grow lights can be installed much closer to the canopies, increasing intensity without burning the plants.
Not only are LEDs better for thermal management, but they are also far more versatile with their spectral outputs. LEDs offer more precise and targeted wavelengths to benefit specific types of crops health and yield. This is an area where HPS lamps are lacking, as they typically produce great quantities of yellow and green wavelengths, which do have fewer benefits to plant growth, yield, or quality. They do not offer a targeted spectrum of light wavelengths like LEDs do. E.g., full spectrum LEDs which mimic natural sunlight, whilst including high peaks of key red and blue wavelengths. LED grow lights provide targeted spectrum recipes to suit different plant stages of growth. They can be tailored to focus on key wavelengths such as blue and red to fulfil the exact needs of the plant.
Finally, LED solution can offer more control and intelligence. With ever-evolving lighting control technologies, growers can implement smart LED systems that allow for Wi-Fi-enabled devices to pinpoint exactly what the grow lights do, and when. As well as allowing the capabilities to adjust the light spectrum to suit the specific plant type and/or growing stage.
