According to the latest report in the Technology Tracking series LED Quarterly Insights - produced in collaboration with LEDs Magazine - the current lack of standardization is preventing lighting designers from making a realistic evaluation of the cost benefit of adopting LEDs rather than other light sources. Since performance measurements aren’t yet reliable and consistent, the LED community is concerned that solid-state technology will only be chosen for applications where the advantages are obvious and the higher cost can clearly be justified.
Some of the key pieces of information that lighting specifiers need to know include:
- Accurate and reliable figures for the actual light output and efficiency of an installed system, as well as for individual LEDs. All data must be presented in a consistent format to enable easy comparison between different lighting products.
- A realistic estimate of LED life. Long lifetime is touted as one of the key benefits of LED technology, but there is no standard definition of LED life. Most manufacturers favour the use of lumen maintenance values, which measure the amount of time taken for the lumen output to fall to a certain percentage of its initial rating.
- An understanding of the colour characteristics of LEDs. One of the most controversial metrics is the colour-rendering index (CRI), which is meant to provide a measure of colour quality but is recognized to have several shortcomings, particularly for LEDs. A reliable and consistent method for colour binning is also needed to sort LEDs according to their colour characteristics.
- A comprehensive assessment of any safety or installation issues. No safety standards are currently dedicated to LED light sources, and concerns are growing that some high-power LEDs could cause eye damage.
- A realistic estimate of the cost associated with deploying a particular lighting solution. The standard cost-per-lumen figure only measures the initial installation costs, while alternative “cost-of-light” metrics take account of the reduced running costs enabled by LEDs’ longer lifetime and reduced energy consumption.
For real progress to be made, LED manufacturers must work together -- and with their customers -- to define best practices for the design and use of LED lighting products. Until then, LED suppliers at all stages of the supply chain must ensure that all performance data reflects how LEDs will perform in real-world applications, which will give lighting designers greater confidence in their product choices and so drive future business growth.
The latest report in the LED Quarterly Insights series, entitled “Performance and Standards”, assesses the current status of standards development and analyses the metrics that are commonly used to characterize LED performance. Other reports in the series focus on high-power LEDs, white LEDs, and packaging and optics. For more information, see www.technology-tracking.com.
