On Sunday, for one hour, Israelis turned off the lights and took part in the annual Earth Hour -- a worldwide event encouraging households and businesses to turn off their non-essential lights for one hour, part of the annual Earth Day activities. This year, Some 22 Israeli cities were involved in this project. The lights out began at 8 pm in a gradual manner -- so as not to damage the national electric grid. Cities one by one joined in every 10 minutes. Last year, some 700,000 Israeli residents turned off their lights in 67,000 households for one hour throughout the country, breaking a record in energy conservation and saving a total of NIS 50,000.