The new rooftop lighting system is the latest phase in a process that has seen 15,000 energy-efficient bulbs installed at the two hotels.

By next month, the floodlights at the hotel entrances will also be changed to an LED product.

Further energy savings at the resort are achieved through an automated system that switches external lighting on and off at sunset and sunrise. 'We calculate the time of sunset and sunrise every day,' Chan said. 'We input the daily calculations and the computer makes the adjustments automatically.'

The result has been a reduction in energy use for these lights by 4 to 5 per cent.

The Walt Disney Company has set a corporate goal of reducing electricity consumption in its business units by 10 per cent by 2013 compared to 2006.

Hong Kong Disneyland achieved the target last year, three years ahead of schedule, and did so over a period when attendance at the theme park, and hotel occupancy rates, increased.

Savings were made in areas including the use of lighting, air conditioning and other equipment at the resort.

Tina Chow, Disney's manager of environmental affairs, said the company was encouraged to see the different mitigation measures were leading to falls in energy use.

She said the results had been achieved on top of the extensive modern environmental conservation measures incorporated into the design of the theme park, which opened in 2005.

By comparison, from 2006 to 2010 overall domestic energy use in Hong Kong rose by 10.89 per cent, while in the commercial sector consumption increased by 4.73 per cent.

The government has launched a public consultation on phasing out incandescent light bulbs, starting with the least energy-efficient varieties.