# ROI Calculator

## CFL Savings Calculator

## ENERGY SAVINGS CALCULATOR

# How are CFL savings calculated?

## Energy Savings Formula:

1. Incandescent watts - CFL watts = Energy Savings

2. Energy Savings x CFL life = Watts Saved

3. Watts saved

---------------------- x utility rate = Total savings

1000 kwh

## Examples:

60 watts -14 watts = 46 watts

46 watts x 10,000 hrs = 460,000 watts saved

460,000 watts

----------------------- x $0.12= $55 saved

1,000 kwh

$55 x 3 bulbs = $165 per pack

## Assumptions:*

- 10,000 hours - the typical life expectancy of a CFL bulb.
- 1000 hours - the typical life expectancy of an incandescent bulb.
- $0.12 - the average cost of energy per kilowatt hour (Kwh).

**can vary depending on region and type of bulb used*

## CO_{2} Savings Formula:

(Incandescent Watts – CFL Watts) x life of CFL bulb x 1.45 lbs |

1000 |

*1.45 LBS is the amount of CO_{2} generated by 1 kWh of electricity (from US Energy Information Administration).

* You must divide by 1,000 to convert watts into a kilowatts.

## Equivalent of CARS taken off of the road Formula:

CO_{2 }Savings x number of bulbs |

118,083 |

*118,083 are the average CO_{2} emissions over the life of a car that would be generated (from US Department of Transportation).

## Equivalent of TREES planted Formula:

CO_{2} Savings x number of bulbs |

2932 |

*2932 is the amount of CO_{2} absorbed by trees over the 100 year life in pounds.