Use Technology Efficiently

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Energy Efficiency

Lighting

Lighting Energy Efficiency

This section will look at what techniques can be used to reduce energy consumption for lighting without replacing whole light fittings. A comparison of costs versus savings be performed to guide where changes should or should not be made.

 

Incandescent Light versus Compact Fluorescent Light

Assumptions

Electricity costs $0.15 per kWh

Incandescent Light bulb costs $1 and lasts 1000 hours

Compact Fluorescent costs $4 and lasts 8000 hours

11 Watt Compact Fluorescent = 60 Watt Incandescent in terms of light output

Incandescent vs compact Fluroescent Incadescent vs CFL table

 

From the chart and table above it can be seen that compact fluorescent lighting is far superior to incandescent lighting in terms of energy efficiency. The only exceptions would be for where expected total use would be below 400 hours. Other factors to consider include space for CFL within the light fitting. Labour needed for light bulb replacement for Incandescent would be 8 times higher compared to CFL.


Halogen versus LED lighting

Assumptions

Electricity costs $0.15 per kWh

Halogen Light bulb costs $3 and lasts 2000 hours

LED costs $100 and lasts 50000 + hours

6 Watt LED light = 50 Watt Halogen light in terms of light output

Halogen vs LED

 

Halogen vs LED table

 

From the chart and table above it can be seen that LED lighting is superior to Halogen lighting in terms of energy efficiency. The only exceptions would be for where expected total use would be below 12000 hours due to the higher initial LED cost. Labour needed for Halogen light replacement for Incandescent would be 25 times higher compared to LED lighting.

Advanced lighting options

These options require an electrician of unknown cost depending on requirements.

  • Add motion sensors to control lighting in areas of occasional use. This could include walkways, tea rooms, entrance ways etc. The sensors will only turn on when its dark and motion is detected. There is a small energy usage for the sensor
  • Add a short timer to a light circuit. This could be for a stairway or garage for 2 minutes.They can be wired in parallel to regular switching if required.
  • Add a 24 hour timer to a light circuit. This could be for security lighting or sign lighting. Adjust the timer for summer and winter daylight hours if required. As these light are on every day this is the place where efficient lighting is important.

Calculate your exact lighting and energy savings ahead of changes.
Light Energy Calculator