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Lighting Energy facts

Switch to energy saving lights

  • A normal 100 watt bulb uses one unit of electricity every 10 hours.
  • Use lower wattage, energy saving light bulbs where feasible – Most use only 20% of the energy that ordinary bulbs use.
  • A typical 11W low energy light bulb will produce as much light as a 60W ordinary light bulb - you get the same amount of light, but using only about 1/5 the amount of electricity.
  • Another way of saying this is that low energy light bulbs are 5 times more efficient than ordinary light bulbs.
  • Compact fluorescent bulbs (CFLs) use 80% less electricity than ordinary bulbs to produce comparable light and last up to 10 times as long
  • Compared to use of an ordinary light bulb, an energy saving bulb saves the environment 13 kilos of CO2 for every hour that the bulb is lit. 

Leaving lighting on overnight

  • Leaving a 60W bulb on overnight when not needed, consumes enough energy to make 24 cups of tea.
  • Lighting an average office overnight wastes enough energy to heat water for 1000 cups of tea
  • Lights on overnight in an average size office (45 people) would waste enough energy to microwave 945 dinners.
  • One large office lit overnight wastes enough energy to drive a small car more than 200km. 
  • Leaving 1 external light on overnight uses the same amount of energy as lighting 36 living rooms with energy saving bulbs for the same period. 

General lighting advice

  • PlugTake advantage of natural daylight as much as possible and use task lighting where appropriate.
  • Turn off lights when rooms that are not in use.
  • Where feasible, use task-specific lighting and reduce the general level of lighting elsewhere. Do not light areas that are not being used.
  • SEI study showed that in the office, 37% always switch lights off, 18% sometimes switch lights off, 45% never switch lights off

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