Saturday, 29 March 2008

Earth Hour - What happened in 2007?

Was there any significant effect and if so, was there any grid instability?

Sydney Central Business District (CBD) showed an estimated 10.2% drop in electricity consumption but only a 2.1% drop in the rest of the metropolitan areas and the grid was stable according to the Australian National Electricity Market Forum (NEMF) Minutes 78 – 26 April 2007.


Wayne Jackson, EnergyAustralia, presented the Earth Hour Impact on the NEM. 'Earth Hour' was the launch event of a 12 month campaign to reduce Sydney's greenhouse gas emissions.

Sydneysiders were requested to turn off their lights for
one hour between 7.30 pm and 8.30 pm, on 31 March 2007. The objective is to reduce Sydney's greenhouse gas emissions by 5% over a 12 month period.

EnergyAustralia's role was to participate in Earth Hour and also to provide load data to help measure the outcomes of the exercise. Media headline results of Earth Hour are shown below:

• 65,000 individuals and over 2,000 businesses pre-registered
• survey reported 2 million households participated
10.2% drop in Sydney CBD Consumption
• saving of 24.86 tonnes CO2-e in Sydney CBD
• saving of 52.08 tonnes CO2-e in Sydney Metro

The impact on the Sydney CBD and the EnergyAustralia network was measured.
Data was collected from 5 substations in the Sydney CBD area. Based on Saturdays in March and April from 7:30 to 8:30 pm, a typical electricity consumption profile was collected and adjusted for temperature (19.8oC on the night) and for daylight savings.

The measured load was 204.9 MWh. The typical Saturday consumption between 19.30 to 20.30 is 228.18 MWh. Therefore, 23.28 MWh of energy was saved, a reduction in energy consumption of 10.2%.

Measurement from EnergyAustralia's
Sydney metropolitan BSPs shows that 48.76 MWh of energy was saved, a reduction in energy consumption of 2.1%.

On the day network stability in the Sydney metropolitan area was very good, there
was no switching or load surge problems at 8:30 pm.

The WWF reported the Sydney CBD figures but didn't mention the much lower result for the greater Sydney metropolitan area.

This year Earth Hour will be on March 29 from 8:00 PM to 9:00 PM (half an hour later).