I just want to say that Earth Hour is just a waste of everyone's time. Turning off power for one hour on a Saturday evening around the world is a novel idea, but it won't do anything to reduce carbon emissions. It is just a symbolic ploy by people who have no clue how energy is developed, generated, and distributed.
For those of you who don't know, Earth Hour is an international event that asks households and businesses to turn off their lights and non-essential electrical appliances for one hour on the evening of 29 March at 8 pm local time until 9 pm to promote electricity conservation and thus lower carbon emissions. (Wikipedia)
Power companies plan their power generation based on historical averages and will have that power available to deliver during Earth Hour whether it is used or not. They will also have reserves available in case demand is greater than the historical averages.
So turning off your power and non-essential appliances for an hour will not save any electricity or reduce carbon emissions for that one hour. Nice idea, just wrong.
A more novel approach is to get people to reduce their consumption permanently. People should replace all their light bulbs with CFL's and make sure your appliances are energy star compliant. (My family has.)
There should also be better ways to generate power individually. I am thinking the cost of putting solar panels on our homes should be cheaper. It shouldn't cost $20,000 to $30,000 to do this. My parents just did this and it was nothing but a hassle to get it installed and for PG&E to get it hooked up to the grid.
We should use water efficiently in our homes and we should reduce the impact of our vehicles by combining as many trips as possible or by taking public transportation. (I just wish public transportation was a lot better in Denver than it is.)
By doing what we can do as individuals and as a society, we can have a bigger impact on energy consumption and reduce carbon emissions than the Earth Hour claims to do tonight.