Below are the assumptions and variables that were used for this calculator:
| Business Variables: | ||
| BES Average Hours Per Day Use | 8.6 | |
| BES weighted avg VT $/kWh | $0.127 | |
| BES Hours Per Year Per CFL | 3,150 | |
| BES KWH Used Incandescent Per Year | 236.25 | |
| BES KWH Used Per CFL Per Year | 19 | |
| BES KWH Saved Per Year Per CFL | 173.25 | |
| BES Lifetime CFL KWH Savings | 660 | |
| BES CFL Life (in Years) | 3.8 | Based on Bulb Life Divided by Hours Per year of use. |
| BES CFL BULB Life (in Hours) | 12000 | |
| Incandescent Bulb Life | 1000 | |
| typical Purchase cost of incandescent | $1.62 | |
| typical Purchase cost of CFL | $6.00 | |
| BES CFL Cost 1st Year | $1.57 | |
| BES Incandescent 1st year cost | $1.58 | |
| Incandescent Lifetime (CFL Bulb Life) cost | $4.00 | |
| BES Days Used | 365 | |
| Residential Variables | ||
| RES Average Hours Per Day Use | 2.6 | |
| RES weighted avg VT $/kWh | $0.148 | |
| RES Hours Per Year Per CFL | 950 | |
| RES KWH Used Incandescent Per Year | 71.25 | |
| RES KWH Used Per CFL Per Year | 19 | |
| RES KWH Saved Per Year Per CFL | 52.25 | |
| RES Lifetime CFL KWH Savings | 440 | |
| RES CFL Life (in Years) | 8.42 | Based on Bulb Life Divided by Hours Per year of use. |
| RES CFL BULB Life (in Hours) | 8000 | |
| Incandescent Bulb Life | 1000 | |
| typical Purchase cost of incandescent | $1.62 | |
| typical Purchase cost of CFL | $6.00 | |
| RES CFL Cost 1st Year | $0.71 | |
| RES Incandescent 1st year cost | $0.48 | |
| Incandescent Lifetime (CFL Bulb Life) cost | $4.00 | |
| RES Days Used | 365 | |
| Lifetime Savings Equivalents: | ||
| 1 kWh = tons of coal | 0.0001644 | |
| lbs CO2 per kWh electricity generated | 1.260 | Source: Avoided Energy Supply Costs in New England: 2007 FINAL REPORT |
| average annual household electric usage in Vermont (KWH) | 7000 |
