Residential Lighting
Cost Comparison
Compact fluorescent lighting one 15-W bulb |
Incandescent lighting  ten 60-W bulbs |
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| Purchase cost | $2.70 | $0.90 each X 10 = $9.00 |
| Service life | 10,000 hours | 10 x 1,000 = 10,000 hours |
| Energy consumption | 150 kWh | 600 kWh |
| Calculation of energy costs at a rate of $0.0746/kWh | $11.19 | $44.76 |
| Savings for each bulb replaced | ||
| - Energy | $44.76 - $11.19 = $33.57 | |
| - Purchase cost | $9.00 - $2.70 = $6.30 | |
| - Total without cross-effects * | $39.87 | |
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Because CFLs emit less heat than incandescent bulbs, your heating system has to make up the difference during the winter. Even so, you'll save $20.40 over the service life of each CFL bulb used indoors. (Estimate for an electrically heated single-family dwelling).