It's not that simple
To the Editor,
Ontario's electricity grid operator, the IESO, reports that demand in the province was reduced by 920 MW during Earth Hour on March 28 (Re: "Earth Hour cuts power use," NRT April 1).
Since the energy from lighting heats our homes and office buildings, that's 920 MW of heating that was turned off for an hour, from 8:30 to 9:30 pm. At this time on a Saturday, this energy would have been supplied by clean hydraulic and nuclear generating stations in Ontario.
Instead, unless people turned off their heat during Earth Hour as well, this missing energy was supplied by whatever heating source their building has installed.
Unless this heating source is electricity (and the IESO's figure suggests generally otherwise), then the net effect of Earth Hour in Ontario was probably an increase in pollution.
Is Earth Hour an effective gimmick that raises awareness of energy usage? Sure, but it also demonstrates that energy conservation is a lot more complicated than it might seem.