When you, as a gardener, decide to invest in LED, you naturally want to make an informed decision regarding the supplier and the fixture you choose. In the article “Buying LED lights or LED fables?“, we talked about the variables you need to consider when investing in LED. However, we have not yet discussed the long-term performance of LED. In practice, it is challenging to estimate this. In this article, we will look at the long-term performance of LED and show you how you, as a grower, can monitor the performance and degradation of LED lights.
The expected performance is laid down in agreements about guarantees and degradation. However, in horticulture, precise arrangements are made about this much less than in the conventional LED market. Given that LED is a significant investment, we consider the lack of such reasonable deals a considerable risk. It sometimes happens that the LED lamp does not achieve the performance that is claimed in the agreement. For example, the amount of light may vary, the spectrum may not match, or the degradation of the lamp may be faster than predicted. So it is essential to measure your lamps to check the agreement and its conditions.
Verification of performance claims in LED lighting
The investment in LED is significant and for the long term. So, check the purchase carefully upon delivery for performance as specified in the contract. LED lamps can be measured through a Gonio Spectrometer and an “Integrating Sphere”, also called an Ulbricht’s Sphere. With these technologies, you measure output, light distribution and spectrum. From this, you can then determine the efficiency of the lamp (μmol/joule). This is how you find out if the light meets the set specifications. But: What have you agreed with the supplier in terms of long-term performance? Our advice is to make apparent agreements about the degradation of your LED lamps.
Monitoring degradation of LED lamps during the period of use
LED has a maximum number of burning hours, and by using it, the LED will lose some of its light sums over time. It is therefore essential to monitor this percentage degradation.
In addition, you should also keep an eye on the preservation of the spectrum. For example, a red LED chip may last longer than a white LED chip. In other words, one colour LED may degrade faster than different LED colours. This can affect your spectrum over time.
Many light suppliers offer to do periodic checks in the greenhouse, which is like a butcher inspecting his own meat. In any case, when transitioning to LED, we recommend taking independent measurements in the greenhouse. In the event of any deviations, you could have fittings measured by an independent measuring institute.