NEMA’s shipment indexes for high intensity discharge (HID) lamps declined by 11.7%, 17.1%, and 0.9% on a year-over-year basis for sodium vapor, mercury vapor, and metal-halide lamps, respectively. For the year as a whole, shipments of mercury vapor lamps also declined for the fourth consecutive year, dipping 2.7% compared to 2009. Conversely, sodium vapor and metal-halide HID lamp shipments increased during 2010 by 1.1% and 5.2%, respectively.
Sodium vapor lamps showed an increase in market share of nearly 2.0 percentage points ending the quarter at 33.2% of HID lamp shipments. The share of metal-halide lamps registered a reading of 61.8%, a decline of 1.5% points. Mercury vapor lamps gave up market share as well, declining by 0.5 percentage points to 5.0% for the fourth quarter.