Earth Hour 2008

In its global debut, 35 cities on seven continents took part as official flagship cities. Another 400 cities took part and turned out the lights in landmarks.

Non-essential lights went out in the Empire State Building (New York City), Sears Tower (Chicago), Golden Gate Bridge (San Francisco), Bank of America Plaza (Atlanta, Georgia), Sydney Opera House (Australia), Wat Arun Buddhist Temple (Bangkok, Thailand), the Colosseum (Rome), Royal Castle (Stockholm, Sweden), London City Hall, Space Needle (Seattle) and the CN Tower (Toronto, Canada).

The official Website for the event, earthhour.org, received over 6.7 million unique visitors in the week leading up to Earth Hour. Other Websites took part and Google's homepage went "dark" on the hour.

According to a Zogby International online survey, an estimated 50 million people around the world participated in the Earth Hour 2008.

The survey showed a 4-percentage increase in awareness of environmental issues such as climate change, compared with that before the event.

Energy saved in 2008

Toronto saved 900 megawatt-hours, an 8.7-percent saving compared with a typical March Saturday night.

Ireland had a 1.5-percent reduction in energy use for the evening.

Between 6:30pm and 9:30pm, there was a reduction of 50 megawatts, saving 150 megawatt-hours, or around 6 tons of carbon dioxide.

In Dubai, United Arab Emirates, several landmarks went dark and some street lighting was dimmed by 50 percent. The power authority reported savings of 100 megawatt-hours, a 2.4-percent reduction in demand compared with usage before lights-out.

The best result was from Christchurch, New Zealand, reporting a drop of 13 percent in demand.

Melbourne, Australia, saved 10.1 percent of electricity.

Sydney, which participated in both 2007 and 2008, cut consumption by 8.4 percent in 2008, lower than 10.2 percent in 2007, the kickoff year.

Pull the switch - but be careful

The Shanghai Power Co says lights-out is a good idea, but urges everyone to be mindful of the power grid and not turn off big energy-drawing appliances at the same time, then turn them on again.

Power delivery could be disrupted if there's a huge drop and then a surge in demand for electricity, says George Wang in the company's press center.

It takes at least an hour for a powered-off generators to start up again.

In fact, a sudden drop in electricity demand won't result in energy saving, at least in China, says Wang.

Power plants produce and send electricity to a city according to the average energy consumption there. An unexpected sudden drop in consumption won't change the amount of electricity sent by the plant and the extra power will be wasted - it cannot be stored, says Wang.

Even though the plant has been informed in advance and will reduce energy production, the energy saved is minimal.

A sudden surge in demand that cannot be met immediately by the plant may disrupt power supply.

Private lighting doesn't represent a big proportion of electricity consumption in the city. The energy gobblers are big TVs, heaters, air conditioners, computers and electronics.

"Saving energy is not a one-hour-a-year show." says Wang. "We can switch off light together to take a stand, but preventing energy waste every day can make much more significant difference."

Earth Hour Website: www.earthhour.org

(Shanghai Daily March 24, 2009)