Most energy-efficient' LED light revealed by Philips

[Filliam H. Muffman]

Another thing to look at is how much heat energy the new LED's give off. A LED that is twice as efficient as current models gives off ~60% less heat. That reduces cooling loads in addition to lower power to generate light. It reduces the size of the heat sinks to cool them so it means less aluminum to make them, so they will eventually be cheaper and lighter.

[space-time]

this table has data for several types of light sources

http://en.wikipedia.org/wiki/Luminous_ef...efficiency

[August West]

...high bay areas

Must you always bring your neighborhood into the discussion?