DOE questions recent NLPIP LED street light report (updated)

Both the US DOE and luminaire makers believe that the recent NLPIP Specifier Report was fundamentally flawed in questioning the suitability of LED street lights for collector roadways.

The Lighting Research Center (LRC) at Rensselaer Polytechnic Institute (RPI) issued a report earlier this month concluding that LED-based solid state lighting (SSL) was not a viable replacement technology for high-pressure sodium (HPS) street lights. This week Jim Brodrick, the Lighting Program Manager at the US Department of Energy (DOE) responded, writing about the report, “a critical error was committed at the outset which affects all of its conclusions.”

The presumed critical error was apparently the selection of luminaires used in the tests that underlie the National Lighting Product Information Program (NLPIP) Specifier Report. Both luminaire makers and the DOE believe that the LRC selected SSL luminaire that weren’t appropriate for the collector roadway application.

The DOE’s Brodrick wrote, “Although I'm sure it wasn't intentional, LRC selected some woefully underpowered LED products to compare with HPS street lamps.” The link above to our original story about the report issuance also includes a statement from luminaire maker BetaLED about the research. In part that statement reads, “the choice of luminaire was not optimized for the specific application referenced in the report.”

The DOE response came in the form a Postings: from the desk of Jim Brodrick email. Brodrick distributes the Postings on a regular basis. The new one has not yet been added to the DOE web page that consolidates the missives but surely will be shortly.

Apparently, the DOE took issue with the report earlier because essentially the report implies that DOE Gateway LED street light trial reports are misleading. The DOE requested that the LRC revise some of the wording used in the introduction section of the Specifier Report. The LRC posted a PDF with both the paragraph in question and the DOE’s request for a change. As of now, the report 'Streetlights for Collector Roads' remains unchanged although it does include a note at the beginning referencing the PDF linked above.

The DOE also submitted its own review of the tests to the LRC several weeks ago (updated: the DOE posted a PDF of the review). The review identified the choice of underpowered luminaires as a problem as well as other flaws in the methodology. The LRC hasn’t responded to that review and now the issue has become very much public. Expect more in the coming days.

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