Questions and Facts
Q: Is it more energy-efficient to let a light bulb burn for a short period of time or to turn it off and then on again? I read once that the surge in power when a bulb is turned on is equal to letting the bulb burn for a while?
A: It is more energy efficient to turn the light off than to leave it on. Energy is measured with respect to time. The unit used to measure electrical energy is the kilowatt-hour or thousand-watt-hour, the amount of power or watts that you use in one hour. The momentary or millisecond or less surge of electricity required to start your light bulb will not impact your energy cost but leaving it on all the time will. With the rising cost of energy, it’s probably a good idea to turn the lights out when you are not using it. (Not to mention the pollution impact, less energy use, less emissions from power plants.) Turning the lights on and off a lot will impact your lamp life, however. If you compare the number of bulb(s) you need to buy versus the cost to let the light burn all the time, it will still probably be cheaper to turn the lights off.
Q: Does my screensaver save energy?
A: Screensavers do not save energy and may even prevent your system from going into a low-power sleep mode when not in use. Screensavers were developed in order to lengthen the life of monochrome monitors. Technological developments have made them obsolete: they certainly don't save energy or the environment! Disable your screensaver today and replace it with our energy management software.
Q: How much damage can one computer cause to the environment?
A: One desktop computer left on all day for one year can result in more than 1,500 pounds of carbon dioxide being released into the atmosphere. It would take 100 to 500 trees to offset that amount of extra carbon dioxide.
Q: What is the University policy on space heaters?
A: We discourage the use of space heaters on campus. A typical space heater can use 1.5 kilowatts of energy and over $400 a week. Space heaters can be a fire hazard in small areas such as a dorm room or office. These heaters also cause building air conditioning systems to work harder by adding heat to your office and can interfere with climate control systems.
Q: What is the most energy-efficient thing to do with your computer at the end of the day? Turn it all off or just turn off the screen or leave it all on? I don't have an Energy Star computer.
A: Just like fluorescent lighting, explained above, turn off your computer in order to use less energy, especially if it does not have an energy-saving mode.