Lights out, candles on for Earth Hour

The lightbulbs are off and the candles lit in Australia's eastern states for the ninth annual Earth Hour.

Hundreds of millions of people are expected to turn off their lights at 8.30pm local time, wherever they are in the world.

The Sydney Harbour Bridge and Melbourne's Federation Square are joining some 1200 landmarks including the Eiffel Tower and the Golden Gate Bridge in the US in going dark.

That's in addition to some 300 community events across Australia.

However, two places not going dark will be the Sofitel hotel in Sydney's CBD and the Dooley's club in western Sydney, where the Liberal and Labor parties are holding respective NSW election night functions.

Pioneered in Australia in 2007, Earth Hour has since grown into a massive worldwide event, with 162 countries participating last year.