The US DOE’s L Prize program has been conducting long-term testing of the 2009-vintage Philips 60W L Prize-winning LED A-lamps.  The results are crazy impressive!

A selection of 31 of those lamps passed the 40,000-hour point of continuous operation in July 2015. The average lumen maintenance for the 31 lamps after 40,890 hours was 95.6%, with no failures. At that rate it would take an average of 194,765 hours of operation for the lamps to reach 70% lumen maintenance (L70), if no other failure modes came into play before then. The average chromaticity change (?Δu’v’) of the 31 lamps after 40,890 hours of operation was 0.00093 – a minuscule difference indicating that there was no detectable color shift, and that the light emitted today is indistinguishable from the light emitted four years ago.

194,765 hours to L70 (70% lumen maintenance)!!!!  To help you with the math, that’s 22.2 freakin’ years of nonstop, 24/7 operation!

Burn, baby, burn!  I hope the DOE keeps this test running for a few more decades!!!!  Let’s see how long it takes to L50!  MTBF, anyone?