I agree with you, that is a very shoddy piece of journalism. The LEDs are almost certainly less efficient than the sodium lamps they replace. http://en.wikiped

I agree with you, that is a very shoddy piece of journalism. The LEDs are almost certainly less efficient than the sodium lamps they replace. http://en.wikipedia.org/wiki/Luminous_efficacy#Examples_2 http://en.wikipedia.org/wiki/Luminous_efficacy#Examples_2 Prototype LEDs are reaching 130 lumens/watt, low pressure sodium regularly get 150 lumens/watt in production. The efficiency of the LEDs used is probably around 80-90 lumens/watt. The money saving is probably coming from the lower maintenance costs whilst there is an increase in energy use.