While people believe they spend all day gazing into their computer monitors, the time actually spent is probably closer to half the day, or about four hours. However, computers are on for the full work day and sometimes at night if they are not switched off.
The computer may go into a power saving mode, but does not completely turn off. When the monitor shows a screen saver, it is still using full power .
The standard deep-backed desktop monitor uses about 120 watts to function. This may not seem a lot until multiplied by the number of:
- hours in a work day,
- monitors at Council (about 1000) and
- work days in the year.
Approximately 239,000 kilowatt hours of power was required to run the old monitors each year.
In 2004 and 2005, Council replaced all of the computer monitors with new 'flat' energy efficient monitors that require only 24 watts to operate or 47,800 kilowatt hours of power a year. The upgrade saved approximately 191,000 kilowatt hours a year.
The upgrade also has additional benefits as the new monitors are:
- lighter,
- take up less space,
- are more durable,
- have a greater proportion of recyclable material and
- generate less heat.
The old monitors also produced approximately 90 watts of waste heat. There was therefore an unexpected side effect to the upgrade: an increase in winter energy use as the building required additional heat from the central heating system. But was a substantial drop in summer electricity use as the air conditioning system had less heat to dissipate from the building.
The heat generated by the old monitors was equivalent to:
- 900 x 100 watt incandescent lamps or
- 45 fan heaters (two kilowatts) or
- 45 electric jugs or
- 45 ovens.
The new monitors also use a lot less power when in the power down mode - approximately one watt per monitor per hour.
Switching off monitors at night and over weekends, could save Council roughly 5830 kilowatt hours a year - sufficient to supply electricity to a medium-sized household for at least six months.
Seemingly small changes may make a big impact on both costs and energy and Council continues actively to seek methods to reduce energy costs for minimal or no cost.
The benefits of the project
- A reduction in energy use by Council.
- An upgrade in the working conditions of the staff.
- A reduction in cooling required in summer in the Civic offices.
- The new monitors will operate for longer thus saving future capital expenditure.
- The new monitors require less space, thus reducing desk space required.
Things to consider for your business or home
- What equipment could I upgrade that will result in energy savings?
- Is there a refrigerator or freezer that is underused that may be emptied and switched off?
- What equipment/appliances could I turn off-either permanently or at night, which will reduce my electricity consumption?
- Is there any equipment whose temperature is set too high, such as heating or cooling, which should be reset according to best practice?
