What is LED? LEDs have been around for over 50 years in colours
red, orange, yellow, blue, green and then sheer white. These
have come a long way from being tiny indicator lights that tell
one when an electronic appliance is switched on. They are
beginning to get noticed in India as an energy saving option for
lighting buildings and streets though still a speck on the
horizon. Delhi has replaced 150 Watt solar vapour lamps in
streetlights with 50 Watt LEDs in a residential locality early
this year. What is the benefit? Unlike incandescent bulbs, LEDs
do not have filament that is heated to create light. These are
illuminated by the movement of electrons in a semi conductor
material (diode). Since electricity is directly turned into
light, LEDs waste less energy as heat. Energy consumption is
lower than CFLs that use mercury vapour to produce light. LEDs
have taken over CFLs promoted as the most advanced lighting
device, in energy efficiency. A 5 Watt LED can replace a 15 Watt
CFL, saving Rs. 77 on the electric