The LRC report released recently has sparked some interesting and constructive debates across the Internet and the lighting industry (read our reaction to the initial report). The LRC has published an addendum to its study on November 9th, featuring tests conducted with more recent luminaires, and released a statement on November 16th. Here’s what I think of it.
First, I must say I’m pleasantly surprised – my hat goes off to the people at LRC for such a quick response. The LRC reacting so promptly shows that the industry and the specifiers can rely on them as a valuable source of information.
If I may, however, I would like to make a few comments because I think we could use more numbers and details about the tests conducted and the luminaires.
- For example, when the LRC mentions that the chosen luminaires respect “either the illuminance or the luminance roadway lighting criteria,” they should let us know which luminaire respected what criteria.
- What does it mean to respect the RP-8 standard “without over-lighting?” It would be very interesting to know more precisely at what point it becomes over-lighting for the LRC, as people tend to interpret this differently. We know the minimum requirements, but not the actual performance.
- The uniformity of the tested luminaires should be published so specifiers know if there is a link to be drawn between the cost and the quality of a luminaire.
- While I appreciate the fact that the LRC wants to compare oranges to oranges, I’m not sure if it’s right to use the same Light Loss Factor (LLF). The difference may be small, but the LLF is still not the same for HPS and LED and their method is consequently not representative of real-life.
- The LRC attributed a 30,000 hours lifespan to HPS, but it usually is around 24,000. Except maybe for non-cycling HPS lamps, but they come at a premium and this would influence the value life cycle cost. The upfront cost, the relamping cost, and the relamping frequency are all influenced by this.
- I’m not very comfortable with the fact that they still consider relamping LEDs at 25,000 hours. Even though the graph also shows an example of different relative costs, relamping at 25,000 hours is not a realistic scenario and, at first glance, the graph makes LEDs appear as a very expensive option. But maybe that’s just me.
- The prices of two luminaires “were not available from the manufacturer representatives.” So instead, the LRC used the prices of other luminaires. The difference may or may not be significant – we simply don’t know – consequently, I think the validity of the conclusions could be questioned, at least for these two luminaires.
So, overall, my point is that the LRC did some great work – and fast. But if they could also provide the data that is missing, it would be even better!