County of San Mateo RecycleWorks Facilities

San Mateo County Facilities
The recycling program for county employees

Energy Myths

Myth #1: Appliances use no energy when turned off.
False. When you turn off an appliance or electrical device, it may continue to consume electricity. Sometimes appliances use as much power off as when they're on! A large number of electrical products, from air conditioners to DVD players, remain in "stand-by" mode and cannot be switched completely off without unplugging the device or turning it off at a power strip. This "stand-by power" draws power 24 hours a day. When you add up the power use of all of the appliances and electrical devices in your home or office the power consumption is substantial.

The following is a chart showing stand-by power consumption by type of appliance from the Lawrence Berkeley National Laboratory:

Appliance Category

Appliance

Power Consumption
In Watts

 

 

Min

Avg

Max

Audio

Portable Stereo

0.7

2.2

7.7

Compact system

1.3

9.7

28.6

Component System

1.1

3.0

15.1

DVD Player

1.3

4.2

12.0

Radio, Clock

0.9

1.7

3.2

Battery

Battery Charger

0.5

0.9

1.4

Lawnmower

1.4

7.6

20.0

Power Tool

0.6

2.0

3.3

Vacuum Cleaner

1.7

2.1

2.6

Home Automation
and Security

Garage Door Opener

1.4

3.0

4.0

Security System

4.5

13.7

21.5

Kitchen

Breadmaker

1.4

1.6

1.8

Microwave Oven

0.0

2.9

6.0

Rice Cooker

1.5

2.0

2.5

Office

Computer

0.0

1.7

3.5

Printer, Ink/BubbleJet

4

5

6

Phone/Fax/Copier

1.3

1.5

1.6

Set-top Boxes

Cable Box

4.6

10.8

24.7

Internet Terminal

4.4

10.6

18.8

Satellite System

8.8

12.6

18.8

Video Game

0.9

1.3

2.0

Telephone

Answering Machine

1.8

3.0

5.2

Cordless Phone

1.1

2.6

5.0

TV-VCR

Television

0.0

5.0

21.6

TV/VCR

1.1

7.6

19.5

VCR

1.5

6.0

12.8

White Goods

Range

0.9

2.7

4.1

Myth #2: It doesn't matter whether I turn my computer off or leave it in sleep mode.
False. Computers should be shut off when not used for long periods of time, such as overnight. When you're away from your computer for shorter periods, its okay to use the "sleep" or "energy-saver" mode. This will turn off the monitor, but your computer will not have to be restarted. The biggest electricity draw is the monitor, which can use from 50 to 150 watts, depending on its size. Flat screen monitors use only 10-15 watts. Switching the displays and terminals off at the end of the day would save 85 watts per computer. Source: California Energy Commission

Myth #3: Leaving a fluorescent light turned on uses less energy than turning it on and off and makes it last longer.
FALSE. You should turn off your fluorescent lamps if the space is not going to be occupied for more than a few minutes (3-5 minutes is a good rule of thumb). The startup does use a higher level of electricity but it only lasts for a fraction of a second, which is negligible compared to leaving the light on. For example, turning off a fluorescent lamp for one-half hour versus leaving it on will save about $4.00 (based on 8 cents/kWh) in energy over the life of the lamp. In fact, the money saved by this routine is typically more than the price of a new lamp. Turning fluorescent lamps on and off will shorten their life, but this impact is very minimal, since fluorescent lamps typically last 10 times longer than incandescent lamps. Source: California Energy Commission