'Earth Hour' in Ireland is being heralded as a success after analysis released by EirGrid shows a reduction in electricity use of about 1.5% yesterday evening.

Earth hour 2008 is a global campaign to get homes and businesses around the world to reduce their electricity use and turn off non-essential lights between 8pm and 9pm last night to raise awareness about climate change 

Cathy Flanagan, Campaign Organiser for Earth Hour Ireland, is hoping the event will gain momentum.

Around the globe, up to 30 million people were expected to have turned off their lights for 60 minutes by the time ‘Earth Hour’, which started in Suva in Fiji and Christchurch in New Zealand,completed its cycle westward.

More than 380 towns and cities and 3,500 businesses in 35 countries signed up for the campaign that is in its second year after it began in 2007 in Sydney, Australia's largest city.

In Australia more than half of Australian adults switched off their lights according to organisers.

Cities across Australia took part in Earth Hour 2008, with iconic buildings including Sydney's Opera House and Harbour Bridge to Melbourne's Flinders Street station switching their lights off at 8pm local time.

In Canada, the 553-metre CN Tower in Toronto and the surrounding skyline were plunged into temporary darkness.

In the US, landmarks such as San Francisco's Golden Gate Bridge and Chicago's Sears Tower went dark in the closing hours of the event.

The lights were switched off on six main roads in Bankok and three of the city's landmarks were also left in darkness, including the Temple of Dawn, the Rama VIII bridge and Ratchadamnoen Avenue.

In the southern New Zealand city Christchurch, energy distribution company Orion said power consumption dropped 12.8 percent during Earth Hour.

In Britain, The Prince of Wales' residence in Gloucestershire, Highgrove House, and Winchester Cathedral were among those plunged into darkness as part of Earth Hour.

Organiser WWF-UK enlisted the support of 28 local authorities to switch off their lights between 8pm and 9pm last night.

These included London, Birmingham, Plymouth, Coventry, Bournemouth, Cardiff and Norwich.

The lights were also turned off at the Welsh Assembly, Warwick Castle, Brighton Pier, the theatre district of Milton Keynes and all the arcades in Great Yarmouth.