In Switzerland, Migros is the first supermarket to switch to 100% LED lighting.
The energy saving from LED is currently around 90% of Compact Fluorescent Lamp, which in term is about 8 times more efficient than traditional incandescent light bulb, i.e. LED is about 80 times more efficient than regular light bulb.
When we move to the new apartment this week, I am going to experiment and purchase some LED lamps for the desk as well as the living room from Koncept Technologies. The saving should be substantial but currently LED 'bulb' is about 10 times more expensive than CFL so only the most used lighting will be justifiable purchase.