Switching 20 halogen bulbs to LED saves 745 kWh and 214 € a year (energy plus replacements). The LEDs pay for themselves in 3 months and last about 14 years at 3 h/day.
Savings per year
€214
186 electricity + 27 bulbs avoided
Energy saved
745kWh/yr
81% less power
Payback
3 months
60 € of LEDs
10-year net saving
€2,075
Cost per bulb per year: old
€11.50
Cost per bulb per year: LED
€2.19
CO₂ avoided per year
261kg
LED efficacy
100lm/W
old bulb 19 lm/W
Equivalent wattages by brightness
| Lumens (lm) | Incandescent (W) | Halogen (W) | CFL (W) | LED (W) |
|---|---|---|---|---|
| 250 | 25 | 18 | 6 | 3 |
| 450 | 40 | 28 | 9 | 4.9 |
| 800 | 60 | 42 | 14 | 8 |
| 1,100 | 75 | 53 | 18 | 10.5 |
| 1,600 | 100 | 70 | 23 | 15 |
| 2,600 | 150 | 105 | 42 | 24 |
- Equivalent wattages follow EU Regulation 2019/2020 and ENERGY STAR lumen-equivalence tables. Halogen ≈ 15 lm/W, incandescent ≈ 13, CFL ≈ 60, LED 90–150.
- Heat interaction: in winter the waste heat of old bulbs slightly reduces space-heating demand, and in summer it adds to the cooling load. Leave it at 0 for a pure electricity comparison.