Lamp/light source efficiencies
From Ukastle Reference Section
The figures below are for the various efficiencies in terms of Lumens/W for different lamp types. The higher the Lm/W, the more efficient the light source. The data is based on web info for Philips lamps with the exception of SOX which is via Lamptech.
Note this doesn't tell the whole story as except for the LED lanterns, no control gear losses are included.
SOX gear is more lossy than SON. 35W SOX circuit loss is very similar to 50W SON. 135W SOX circuit loss is similar to 150W SON.
26W SOX-E: 141 (replaces 35W SOX)
35W SOX+: 130
35W SOX PSG: 126.3
36W SOX-E: 163 (replaces 55W SOX)
55/90W SOX: 120
66W SOX-E: 164 (replaces 90W SOX)
135W SOX: 135
180W SOX: 150
Directly interchangeable with SON
As used by Highways Agency for Iridium retrofits on trunk roads
"traditional" CDM lamps
Fluorescent used in Surrey and south coast PFI for residential lighting
As in Philips BGP32X lanterns
59.1 (4200Lm, 48 LEDs)
84.4 (16800Lm, 160 LEDs)
SON Master PIA
With the exception of the 400/600W SON, SOX is still the most efficient discharge light source.
CDM-Elite/Cosmopolis are comparable in efficiency to the medium SON lamps, CDO-TT and CDM are the less efficient types of MH lamp.
PL-L is similar to "conventional" MH.