Lighting can use up to 40% of energy in commercial premises, depending on the nature of the business and type of lighting used. Street and public lighting is the single largest source of carbon emissions for local governments.
Old-style incandescent (including halogen) bulbs are highly inefficient, burning most of the energy they use as wasted heat. This also makes them a fire risk.
Light emitting diodes (LEDs) use up to 75% less energy than old halogens. They also last up to 25 times as long, which greatly reduces the need for changing or maintenance. This is especially useful where fittings are difficult to access. Also, because LEDs generate less heat than halogens, the load on air conditioning is reduced.
LEDs can be of varying quality, so look for reputable name-brand products.
A good energy efficient lighting strategy relies on an integrated approach that includes the following elements.
Reduce demand for artificial lighting
There are several highly effective strategies to maximise natural lighting indoors. Measures include the use of light-coloured internal surfaces, skylights, shading device control, glare reduction and electrochromic glazing.
Optimise the use of existing lighting systems
Many lighting efficiency opportunities can be easily implemented with little or no capital investment or need to redesign a lighting system. These include turning lights off manually or automatically when not needed, or removing excess lamps from over-lit areas.
There are excellent opportunities for energy saving whenever upgrades or refurbishments are planned. Options for upgrading energy-efficient lighting can be applied to all types of commercial, industrial and service facilities, and may include replacing light fittings and lamps, optimising lighting layout, and adding more circuits and switches for greater control and automation.
Improvements in LED lighting have the potential to reduce lighting bills by more than half. Innovations are also bringing down the costs of high-tech windows, such as low emissivity glass opening up daylighting options while minimising glare and heat gain in commercial buildings.
Electrodeless induction lamp and LEDs
The induction lamp’s main advantages are long life, ease of replacement and low maintenance. These lamps have mostly been applied where high lamp replacement is difficult and expensive. The efficiency of induction lamps range from about 56lm/W to 80lm/W. This is less impressive than some LEDs (90lm/W or more) which are also claiming equivalent lamp life and lower long-term capital costs. As LEDs further improve in power output and live up to the predictions of lamp life, they can be expected to compete increasingly successfully with induction lamps.
Simulation and new building materials
Computer simulation helps designers provide daylighting without admitting direct sunlight. New glazing materials admit light while blocking infrared and ultraviolet light. Double-glazed windows admit light while halving heat conduction, and various low emissivity coatings (‘low-e’ glass) can also help to manage radiant heat gain and re-radiation from the glass. Other innovations worth exploring include light pipes, panels that reflect light onto ceilings, and aerogel panels that insulate whilst letting daylight through.
Energyrating.gov.au Energy Rating
Energy Efficient Lighting Guide NSW Government
Australian and New Zealand Standards – 1680.2 (PDF 640KB) SAI Global