The chief minister's call to save electricity comes at a time when the national capital is reeling under a power crisis.

Though many residents joined the campaign as a matter of responsibility, there were some who did not.

'I am now sitting in the dark though many of my neighbours are enjoying their ACs. As a responsible citizen I did my bit,' said Kishore Mishra, a young scientist.

'My friends and I sent e-mail and text messages to relatives, friends and acquaintances asking them to switch off the lights during Earth Hour,' said Charu Gupta, a college student living in Malviya Nagar.

Uzzwal Madhab, who started the Earth Hour 2009 group on Facebook, said: 'I welcome the Delhi government initiative and we have been asking people to join hands in saving power. We want people across India to take part in such campaigns for the welfare of mankind.'

According to the government, the quarterly affair could save up to 400 MW of power in a year.