Dear editor,

Energy efficient lights better for the environment and star gazing 

The primary objective of street lighting is to keep communities and road users safe at night.

The use of energy efficient street lights can do this in a way that reduces sky glow, greenhouse gas emissions and energy costs. However councils are also required to meet the criteria set out for road lighting in the Australian Standards. 

The recent story Turn on the Stars quoted Dr Barry Clark as saying “the new lamps also produced 140 per cent more sky-glow”, but this is incorrect.

Technical expert analysis commissioned during the assessment of new lighting technology concluded that the two approved energy efficient lighting options (compact fluorescents and linear ‘T5’ fluorescents) produce between 3.2 per cent and 5.1 per cent upward light spill.

Current 80 watt mercury vapour lamps produce 10.9 per cent upward light, so new energy efficient lights will reduce the light going up by between 53 per cent and 71 per cent.

Even the lowest wattage high pressure sodium lights as proposed by Dr Clark to reduce levels of blue light would use twice the amount of electricity and require much higher running costs than energy efficient lighting. This is a financially and environmentally unviable solution.

Dr Clark also recommended using luminaries that produce no light spill above the horizon. The use of luminaries would require twice the number of lights to be installed.

This would significantly increase costs to councils by as much as $500 000 a year, as well as a capital cost of over $10 million to make the change. Doubling the number of lights would also produce more sky glow due to a big increase in reflected light off roads and footpaths.

Councils are committed to reducing both energy costs and light pollution by transitioning to energy efficient lighting, providing light only where it’s needed, and not creating unnecessary light spill.

However, this must be balanced with delivering safety for communities at night, and complying with Australia’s prescribed road lighting standards.

Yours sincerely

BILL McARTHUR

President