Lighting Costs
COMPARISON OF LIGHTING COSTS
The cost of running a light is directly related to the wattage of the globe plus any associated ballast or transformer. The higher the wattage, the higher the running cost.
The type of lighting you choose will affect the amount of electricity used, your lighting bill, and greenhouse gas emissions.
CHOOSE THE RIGHT LIGHT
The most energy efficient light is natural light. Well designed north-facing windows, skylights and light tubes let in light without adding to summer heat and winter cold. Light coloured interior surfaces, especially in south-facing rooms and hallways, reflect more light and reduce the level of artificial lighting required.
- Most rooms need two types of lighting. General lighting is needed for all over illumination. Task lighting is used to illuminate specific areas, such as benchtops and desks. Different light bulbs and fittings should be used for these two purposes. Accent lighting can also be used for decorative or dramatic effects.
- Pendant or surface-mounted light fittings can be used to provide general lighting. Use desk, table or standard lamps where most light is needed, such as for reading, so less lighting is required in the rest of the room.
- Use fluorescent lights where lighting is required for long periods of time, such as living rooms, over kitchen benches or on desks.
- Most fluorescent lamps do not switch on immediately. This is a design feature to lengthen the life of the tube. Fluorescents also take a minute or so to reach their full brightness so they may not be suitable in areas where immediate light is required.
- The light output of CFLs is reduced at low temperatures, so they may not be suitable for outside use in very cold areas, or you may need to use a higher wattage lamp.
- The light output of most lamps reduces over time. This is a problem with fuorescents as they last so long. To ensure adequate light output over their life it is worth buying a higher wattage lamp initially to offset the drop in light output.
- Try to use incandescent lights for general or task lighting only in rooms used infrequently and for short periods, such as laundries and toilets.
- Downlights provide bright pools of light rather than general illumination. Up to six downlights may be required to light the same area as one pendant light. They can also cause gaps in the ceiling insulation, particularly if they require clear space to allow heat to dissipate. Think about other ways of lighting with fluorescents before installing halogens. If used, fit lower wattage and more efficient bulbs.
- Choose light fittings that allow most of the light through so a lower wattage lamp can be used. Some light fittings can block 50 percent or more of the light.