Residential conservation is nice, but the load residences play on the system throughout the day is miniscule compared to that put on the system by commercial and industrial properties; moreover, part of the problem is that infrastructure development died a quick death in the Mike Harris/Ernie Eves years in Ontario, while residential building continued. The combination of these two factors, plus McGuinty's inability to actually make decisions that might benefit Ontario (if possibly annoy some Ontarians), is leading to the current power problems.
McGuinty's new big plan, for those who don't know, is to install so-called "smart meters" on all buildings. The meters are "smart" in that they can store information on electricity usage by the hour (indeed, by the minute) instead of a simple cumulative total. (They will also not have to be manually read, as the data will be sent, encrypted, to a collector mounted on a nearby hydro pole. This data can then be read via a PDA held by a meter-reader walking down the street; it can also be sent remotely to a central database that automatically collates the data and bills the consumer.) Thus, consumers can be billed not only for how much electricity they use, but also differentially by when they use it. This wonderful plan will (1) disproportionately affect those who have no choice about when they use power (e.g., families with two working parents), (2) be of no significant effect on those who use huge amounts of electricity (e.g., big industries who have enough money to cover the price change), and (3) do nothing to solve the infrastructure problem. All in all, it's a wonderful solution that puts more money in the pockets of the utilities are will do little to actually solve Ontario's power problems.