New Delhi, July 30 - The Indian capital will switch off non-essential lights for one hour Friday in a copy of the Earth Hour celebration March 28 that saved a whopping 1,000 MW of power.

Delhi Chief Minister Sheila Dikshit said: 'You did it for an hour in March, saved 1,000 MW, a world record. Let's participate once again once again on July 31. Donate power during Earth Hour.'

The Earth Hour, in which people are urged to switch off non-essential lights, will be observed between 8.30 and 9.30 p.m. The Earth Hour campaign began in Australia in 2007.