NEMA’s lamp indices for incandescent and compact fluorescent (CFL) lamps showed mixed results during the fourth quarter of 2010. Shipments of incandescent lamps were in positive territory for the first time in 2010, increasing 14.3 percent compared to the previous quarter. CFLs contracted for the third consecutive quarter, decreasing 3.9 percent. Both incandescent and CFL index components posted negative year-over-year growth of 9.5 and 8.8 percent, respectively. For the calendar year, incandescent lamp shipments declined 8.3 percent while CFLs declined by less than 1.0 percent compared to 2009 levels. 

CFLs retreated from a record-high market share of 28.2 percent during the third quarter to 22.1 percent, giving back 6.1 percentage points to incandescent lamps. However, CFLs gained market share for calendar year 2010 as a whole, increasing its foothold in the U.S. market by 1.5 percentage points to just over 25 percent. The share of incandescent lamps is likely to decline incrementally over the next four years as each phase of the EISA 2007 efficiency standards is implemented.