NEMA’s T8 lamp shipments index increased 7.2 percent during the first quarter of 2010 compared to the same period a year ago. Moreover, the 2010Q1 index reading is nearly 4.0 percent above the level for all of 2009. T12 lamp shipments posted year-over-year growth of 5.0 percent for the quarter. Shipments of T12 lamps have remained stable over the past eight quarters after experiencing significant declines in volume following the initial phase-out of T12 magnetic ballasts that began July 1, 2005. 

Although T12 lamps are less energy efficient than T8 lamps, many owners of fixtures incorporating T12 lamps have chosen not to purchase new fixtures or upgrade existing fixtures to enable them to operate with more efficient T8 or T5 lamps. Since late 2006 the market share of T12 lamps has hovered around 33 percent. This rate is likely to abate shortly after the last step of the phase-out of T12 magnetic ballasts occurs July 1, 2010.