Get Answers To Your Burning Energy Questions
Please e-mail your questions to us at wecan@mail.wvu.edu.
Q: I have heard that you shouldn’t turn fluorescent lights on and off when I leave my office. Should I turn my lights off to go to a 30-minute meeting?
Years ago, lamp manufacturers strongly advised against switching fluorescent lights on and off because you could reduce lamp life by as much as 20 percent. Since that time, the manufacturers have modified and improved these lamps to provide 20,000 hours of operation compared to 10-12,000 hours for the older style lamps. The newer lamps are far less prone to failure due to switching and it is unlikely that frequent switching will affect lamp life more than 5 percent. Regarding the issue of energy consumption associated with starting a lamp, the same philosophy applies – the newer rapid-start lamps combined with electronic ballasts do not use a significant amount of extra energy when turned on as compared to when they are operating in a steady state mode. A good rule of thumb is that if you are going to be out of the room for more than 15 minutes, you’ll save money by turning out the lights. If you will only be gone for 5 minutes – leave the lights on.
Q: Should I shut my computer off at night?
Learn the answer and how to activate ‘Hibernate’ on your PC.
Q: Is it true that turning a PC off uses more energy than leaving it on?
No, the small surge of power used when turning it on- which varies per PC make and model- is much smaller than the amount used in keeping it on for lengthy periods.
Q: Does turning a PC on and off wear it out?
A decade ago, there was something to this, but not today. It used to be that PC hard disks did not automatically park their heads when shut off, and that frequent on/off cycling could damage the hard disks. Today’s PCs are designed to handle 40,000 on/off cycles before a failure, and that’s a number you likely won’t reach during the computer’s five-to-seven-year life span.
Q: Do screen savers save energy?
No, screen savers keep computers active and fully powered at all times. Please set your computer up to hibernate? when not used during the day.
Q: Do computers use zero energy when turned off??
That’s true only if it is unplugged. Otherwise, a PC utilizes “flea power,” or about 2.3 watts, to maintain local-area network connectivity, among other things. In “hibernate” mode, a PC uses the same 2.3 watts; in “sleep” mode, a PC uses about 3.1 watts. Monitors do use zero energy when turned off.
Energy Facts
- Every winter, the energy equivalent of all the oil that flows through the Alaskan pipeline in a year leaks through American windows.
- During the winter, you can save as much as 3% of the energy your furnace uses simply by lowering your thermostat one degree F (if it’s set between 65 F and 72 F).
- Efficiency counts. The most effective new appliances typically use 50% less energy than older ones.
- Washers and dryers can account for as much as 25% of the energy you use at home (including the hot water for the wash).
- A 60-watt incandescent bulb lasts about 750 hours; a fluorescent bulb with 1/3 the wattage will generate the same light and burn for 7,500 to 10,000 hours in five to ten years of normal use.
- Substituting a compact fluorescent light for a traditional bulb will keep a half-ton of CO2 out of the atmosphere over the life of the bulb.