A tipping point for LEDs

The city of Eugene plans to spend $1.7 million to convert about half its street lights to LEDs, or light-emitting diodes. The switch was going to come eventually, as the declining cost and increasing efficiency of LEDs makes them the most economical choice in an increasing number of applications. Governments, businesses and households worldwide are making the same calculations as part of the greatest revolution in lighting since the invention of the incandescent bulb. A 60-watt incandescent bulb — the kind that is familiar to everyone, and is the cartoon symbol for an idea — emits 16 lumens of light per watt, and lasts about 1,000 hours.