It is true, though, that this only helps if more supply can come into the market quickly enough to help. If "more supply" means "more electrical power generation plants that will take five years to build", that's not something that increased prices in the short term can fix.

Another way of dealing with cases like that, however, is innovation: finding an alternative way to meet the same need that doesn't have the same supply problem. For example, if people know that their state's power grid is unreliable, they have more of an incentive to find ways to decrease their reliance on the grid--solar panels, individual homes with their own generators, etc. But that requires transparency--people have to know, well in advance of a problem happening, that their state's power grid is unreliable, so they can take action. Which means the government has to be honest in telling them what the state of the grid is. That, I think, is where the actual root problem often lies.