How do you measure the value of LEDs? Efficiency.
Anybody with an eye on the tech industry has noticed the rise of LEDs. In farming, they have been accepted – or suffered – with varying opinions. Many traditional lighting users write off LEDs due to their high capital expense while others praise
The truth is, LEDs are fundamentally different from other lighting types. Each difference in the form and function of LEDs impacts the most important factor of farm lighting: efficiency. But what does that efficiency could look like, and how could it change the farmer’s lighting decision?
Form and function of LED lights give them great potential for efficiency
Another fundamental characteristic is that many small diodes – encased in plastic caps not much larger than a pin head – make up one LED lighting array. This allows for versatility in size and shape as well as changing the repair process and opening
3 facets of lighting efficiency
There are three types of efficiency contribute to choosing
1. Wavelength efficiency
The ability to deliver very specific wavelengths to our plants is important because plant
2. Equipment efficiency
Equipment efficiency describes the amount of electricity that is converted into light, and is usually stated as a percentage. LEDs usually reach somewhere between 40 and 50% efficiency, meaning that 40-50% of electricity put in comes out in the form of light.
To put that in perspective, a top-notch HID light would see about 25-30% efficiency. For example: if you switched from a typical 600-watt HID light, a 300-watt LED would produce about the same amount of light. (Remember that since we’re emitting a very specific spectrum, we’ll see another bump in productivity on top of that.)
A common misconception is that LEDs don’t produce heat. They do. For each watt being put into an LED, about 3 BTUs (British Thermal Units, an important unit for calculating heat removal) are produced.
3. Form factor
The form factor is how that light is configured and integrated into the farm. It determines how close you’re able to put the light to the crop and how it uses space in the farm. Three main form factors are panels, fixtures (box-shaped), and bars.
Each form factor has pros and cons – for instance, fixtures typically featured air-cooled LEDs with high intensity, while bars have up to now only been able to offer low intensities.
Other key factors of lighting efficiency
Intensity affects cooling & cooling affects lifetime
While LEDs produce less heat than other lighting, they still produce heat. This is extremely important to know, because when an LED heats up, it produces less light. The cooler you keep LEDs, the better they will perform.
Not only does heat negatively affect the efficiency of LEDs, but it reduces its lifetime. As you can see, heat has a bad relationship with efficiency, light intensity, and lifetime.
Power supplies have their own efficiency ratings
A power supply is the component that converts an alternating current to a direct current – in other words, it converts the incoming power to be used by your lighting equipment. Usually, if you buy lighting as a system, the power supply will come with it. Otherwise, you can find information about the power supply from the power company that you’re using.
Power supplies are usually 80-95% efficiency rating – that means that 5-20% of the incoming power is lost from the power supply as heat. To minimize heat losses from your power supply, go with the higher rating.
Make sure you aren’t wasting all that planning with bad coverage
Coverage is the last thing that affects efficiency. Good coverage is possible when the lights are evenly spread across the face of your plant canopy (this is harder to to with box lights and easier to do with bars) and when they are close enough to the canopy.
Most traditional lights are limited by distance to the plant canopy due to heat that can burn plant leaves. LEDs can be placed closer to the plants than other lights, however, because they produce less heat – LEDs can be right up next to the plants with proper cooling and airflow.
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