The companies developing LED lighting to replace incumbent technologies salivate at the thought of being the one to introduce a viable, high-efficiency, cost-effective replacement for the ubiquitous linear fluorescent troffer. New products aimed at this goal seem to appear almost daily, yet despite millions of dollars spent on research, none to date has even come close.
Researchers from Pacific Northwest National Laboratories (PNNL) told a Web audience this week that the new products get closer all the time, but in their evaluations these replacement LEDs still have far to go. Jason Tuenge and Eric Richman of PNNL in Seattle discussed their findings in a Webcast hosted by the Department of Energy’s Energy Efficiency & Renewable Energy (EERE) program June 20.
What they’ve found is that manufacturers introducing solid-state lamps as replacements for linear fluorescents make a lot of lofty claims with very little data to back it up. In general, the look of the lighting the LED units deliver is getting closer to that of the fluorescents in color rendering index (CRI) and correlated color temperature (CCT). Efficiency is also getting closer, but to truly save energy the LEDs would have to show input power of less than 28W because most fluorescent fixtures are under-driven, said Tuenge. In many cases, these LEDs are only able to save energy in comparison with incumbent fluorescents by delivering lower light levels. Their efficacy, measured in lumens-per-watt, are about the same, at best. And when you factor in the economics, with LED prices of $63 to $120 competing with fluorescents at $2 per tube, it’s not even close. Not yet.
What became clear, though, was that the progress being made by manufacturers is moving very quickly. Test results improve significantly in just a few months’ time.