Changing light bulbs to LED

LED lamps are

• 7 times as efficient as old, incandescent (filament) lamps,
• 5 times as efficient as halogen lamps and
• 50% more efficient than flourescent lamps.

If you replace one old 60 W lamp with a 9 W LED, you save 51 Watt every hour. If you use the lamp 4 hour/day, you save 74 kWh/year.

• You can get LED lamps that fit most existing fixtures. The only cost is to buy the LED lamp. The typical price of a good LED lamp is 2 €.
• One could calculate how much is the saving.