How is it that Hydro Quebec was asking customers reduce draw to avoid a blackout?
Tom,
I am not sure why Quebec Hydro would be asking that of their customers other than that the grid maybe can not handle the peak draw. They do not have a energy generating problem. Their dams on the Saint Lawrence have excess generating capacity. It may be a distribution issue. I am not an electrical engineer, so I am only guessing. Kind of like trying to plug to many items into one outlet or circuit. You overload the circuit and you trip the breaker.
Except the breaker is not 20 amp like in your house. It may be 2 million amps and everyone in Montreal is plugging in their blow dryers at the same time.
Quebec Hydro is not like the Hoover Dam in NV/AZ where only 4 out of 14 turbines are turning because if they opened all the gates it would drain Lake Mead. There is so much water running downhill all the way from Lake Superior that only a small portion of it ends up being consumed. There is plenty left to flow into the Atlantic Ocean. Look at the watershed of the Saint Lawrence River. It is not just the Great Lakes drainage. It is most of the province of Quebec and Ontario rivers flow into the St Lawrence.
It is similar to how much water flows into the Columbia River out west. Why do you think the Chinese spent so much time and money building the Three Gorges Dam. Hydro electric power is by far the cheapest way to generate electricity.