What Is Photosynthetic Photon Efficacy (PPE)?

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What Is Photosynthetic Photon Efficacy (PPE)

What Is PPE?

The ratio of the produced PPF to the applied electrical power in watts is a common way to represent the efficiency of the light fixture. The efficiency unit is μmol/J. The PPE of the lighting system increases with the value of this parameter, as it indicates the amount of electrical energy transformed into PAR. But keep in mind that this figure excludes the wavelength of light above 700 nm and says nothing about how well the light is working on your crops.

How to Measure it?

How to Measure PPE

You can calculate the PPE of a fixture by simply dividing its PPF and wattage. For instance, the PPE of a 60 watt light with a PPF of 168µmol/j is 2.8µmol/j.

HPS has the greatest efficacy rating in the past, up to 1.9µmol/j. But LEDs have already surpassed HPS and are nearing 3.0 umol/j. While HPS efficiency is fixed, LED efficiency will continue to rise.

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Anne Zhang

Anne Zhang

Anne is a senior electronics engineer at Casyoo, a professional LED Lighting solutions manufacturer. With 10+ years of experience in the LED grow lighting industry, she aims to help growers and researchers around the world get a better understanding of LED grow light technology so as to increase their crop yields.
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