Posted: Friday, May 24, 2013
Bryson Elementary School Student Solves “The Great Light Debate”
- “Turn the lights off…we need to save on our light bill.”
- “Leave the lights on…turning the lights off and on uses more electricity.”
- “Turn off the lights when you leave a room.”
- The list goes on…
Employees in the Energy Management Department have requested that all staff and students follow the “Five Minute Rule,” i.e., turn off ALL lights in an area that will be unoccupied for more than five minutes. Many have debated this request saying, “But I have always been told that it uses more energy to fire the lights back up.”
Well, the debate is OVER!
Trevor Benton, a fourth grade student at Bryson Elementary School has proven himself to be a true “myth buster.” According to Trevor, his grandfather was one of those who believed that turning lights off and on used more energy. Consequently, Trevor designed a science fair project that would determine the validity of this myth.
To begin his experiment, Trevor connected four different types of light bulbs to a watt meter.
- 1 – Light Omitting Diode (LED) bulb (8 watts)
- 1 – Incandescent bulb (60 watts)
- 1 – CFL (Compact Fluorescent Light) bulb (13 watts)
- 1 – Shop light fixture that houses two fluorescent tube lights (40 watts each, or 80 total watts)
Conducting his experiment twice, Trevor recorded the amount of energy used by each bulb over a three-hour period of steady burning. He then recorded the amount of energy used by each bulb over a three-hour period, when turning each bulb off and back on every 10 minutes. Consequently, each bulb was turned off and back on 18 times over the three-hour period.
Adopting his grandfather’s opinion as his hypothesis, Trevor assumed that each bulb (except the LED) would use more energy when turning them off and on, than when allowing the lights to burn steadily.
However, this hypothesis was proven to be false. Each bulb used the SAME amount of energy when turned off and on 18 times over three hours, as it did during a steady three hour burn, with exception to the shop light which actually used LESS energy when turned off then back on every 10 minutes.
So, there you have it, as it turns out, it really DOES “pay” to turn off the lights if an area is unoccupied.
View details of Trevor Benton’s project.