The LED luminaires going in around Sydney at the moment are trials. In my local area (Manly, so it's not just the Western Suburbs) two streets were converted a couple of years ago. In other parts of Sydney it's an on going process, eventually all (100%) Sydney street lights will be LED. In the USA, UK and Europe there process is much more advanced and in some cases, such as Davis, California, the local community forced the retrofit from high CCT to a much lower CCT at 1800K, these lights are an amber colour.
The LED street lights going in around Sydney have a much higher efficacy than the lights they replace, they produce many more photons at a higher energy than the existing lights, so they have a lower wattage but the light is brighter. The design of the luminaire also impacts what's happening, with LED street lights the LED itself will have a lens and is primarily responsible for the distribution of light, so that means the light can be controlled and brought to a sharp focus and a sharp cut-off.
I and a colleague from
Sydney Outdoor Lighting Improvement Society recently surveyed some LED lights at Kellyville. These lights used a drop lens on the luminaire, much like the existing street lights, and not a full cut off fixture, one of these lights wasn't mounted parallel to the road surface and was tilted up effectively pointed at the house across the road. The amount of light would be well over the Australian Standard (AS2482) of 1 vertical lux. The luminaires have been designed to limit the rearward throw so the illuminance value behind the light was much lower than would be expected. So light trespass depends on how well the light has been installed.
I attended a lighting conference in Melbourne last year where many of the regional councils gave presentations on converting to LED, I believe 90% of Victorian regional areas have converted to LED, parts of Tasmania and Queensland have also converted, as the crews and skills were available. One council showed a before and after of the light dome. The before image showed a large orange glow the after showed the orange dome gone, in fact what has happened is the blue light from the LEDs has scattered out much sooner than the longer wavelength of the high pressure sodium. The blue scatter probably just wasn't picked up by the camera, the exposure wasn't long enough.
The photos of cities from the ISS show starkly where LED lighting has replaced older forms of street lights, LED street lights are putting more light into the atmosphere, of course if you can see that light at the ISS then the rest of it may be on it's way to alpha Centauri.
Wandering around the suburban streets of Kellyville we spoke to a local, he said that he hadn't noticed the lights had been changed - people don't go outside at night - they don't care.
If you see these LED street lights appearing in your local streets, then I'm keen to know about them, you need to ask council if they know what's happening because the chances are it's the electricity distributor doing whatever they want. The town of Davis in California managed to get a retrofit it should be possible here, there is plenty of supporting documentation to go after Council.
