Earth Hour 2011 is underway in many parts of the world, and organizers estimate hundreds of millions of people will have taken part by the time it hits the west coast.
The annual event, which began in 2007, takes place from 8:30 p.m. to 9:30 p.m.
Thousands of British Columbians in about 80 communities are expected to partake. Last year, BC Hydro reported the province's electricity load dropped by 1.04 per cent -- amounting to 64.6 megawatt hours of electricity, the same as turning off about one million lights.
Still, that number was short of both the 1.1 per cent reduction recorded in 2009 and two per cent reduction in 2008.
The biggest contribution per capita last year was recorded in the north-central village of Burns Lake, which charted a seven per cent drop in electricity.
The event is organized by the World Wildlife Fund, which asks only that participants turn off non-essential lighting.
The group also asks those who use candles to choose natural, non-petroleum based products and never leave them unattended.
The first Earth Hour was held in Sydney, Australia where more than two-million individuals and businesses took part to fight climate change.
