New Technology: LED Bulb Payback Times
Not everyone is interested in just saving energy - many want to know they will save enough money to pay for their investment! At around £16 each, these dimmable LED bulbs are not cheap, but the price will inevitably come down as the technology is developed.
|Data for 8 Bulbs||Halogen||Dimmable LED
|Daily Use (h)||2||2|
|Daily Energy Use (kWh)||0.80||0.084|
|Annual Energy Use (kWh)||292||30.7|
|Annual Energy Cost (£)||40.88||4.30|
The bottom row of the table shows that the energy saved in a year would pay for over 2 of the LED lamps! But let's do some more precise calculations. Grab a pen, some paper and a calculator and then answer these questions. Check your answers at the end, or click for hints!
- What is the cost of 8 LED lamps for the kitchen example above?
- How much money is saved per year if they're used for 2 hours a day on average?
- Calculate the payback time, in years, for buying 8 lamps, used for 2 hours a day.
- Totalight's website suggests an LED lamp "pays for itself in 18 months". How many hours would the kitchen LED lamps have to be used for a payback time of 18 months?
- Explain whether or not a payback time of less than 18 months would be achievable in a school or office using LEDs instead of halogens.