DOE unveils results of Round 2 of testing program
Independent testing of SSL luminaires shows several products that are underperforming or presenting misleading results in manufacturers' literature.
As part of the DOE's Solid State Lighting (SSL) program, the CPTP Round 2 tests were carried out from March to May 2007 on a wide range of products, including replacement lamps, downlights and desk-task lamps. The results, along with those published for Round 1, are available at www.netl.doe.gov/ssl/comm_testing.htm.
The Round 2 results showed widely divergent performance. Some downlights and directional replacement lamps produce light output comparable to similar incandescent and CFL downlights, and have higher efficacy (see Table 1). The DOE says that upcoming testing on more recent SSL downlights is expected to show more that are close to or surpassing CFL products in output and efficacy.
However, replacement A-lamps performed very poorly, producing less than 20 lumens. This is less than 5% of the light from a typical A17 or A19 incandescent lamp and makes the LED version very unsuitable as a "replacement" in most situations. Moreover, the manufacturer's literature for one such A-lamp suggested that electricity consumption was 80-90% lower. In truth, this was purely as a result of the very low light output.
Disparity between test results and manufacturers datasheets was highlighted in Round 1 of the testing program, and the situation has not improved. The Round 2 results showed that only two of the tested products had test results similar to the manufacturer's literature. All the other products overstated their performance claims by 25-35% for efficacy and 30-95% for light output.
Outdoor lamps and refrigerated display case lamps performed well in terms of efficacy and light output. Other factors may be as important as efficacy for these applications, including cold temperature performance, longer lifetimes, controllability, dimmability, and insensitivity to frequent on/off cycling.
However, the biggest discrepancy occurred when off-state power consumption was considered. As shown in Table 2, the LED product (07-22) consumes a huge 2.5 W of power when nominally switched off, as a result of inefficient electrical design. As a result, the average efficacy for the LED products is much lower (for more on this subject, see Make sure the LED luminaire you choose is a "Sleeping Beauty").
Round 2 also looked at power factor. In the draft Energy Star requirements for SSL luminaires, the minimum power factor value is 0.7. All the Round 2 luminaires that are integrated fixtures have power factors above 0.7, while those that are replacement lamps are below 0.7 (and the A-lamps were below 0.4).