Your definition of infrastructure. Mine is the transmission of said energy.
Yeah, this bears discussion because it's not easy to know how to demarcate that. A power "grid" is very much its own animal because it abstracts the generators. They're just boxes annotated with so many megawatts, and the switching network and transmission lines (which have fixed maximum capacities) become the engineering problem. But engineering the grid for both reliability and flexibility means making decisions about what loss of generators can be sustained before a cascade failure occurs, and estimates of how likely that's going to be.
That in turn means assessing the reliability of generators under various load and environmental conditions. You have the direct consequences of inclement weather, such as fog freezing on wind turbine blades. But you also have indirect consequences such as the impact on the generator's energy supply chain. If you rely on natural gas pipelines or gas brought in by train car, and snow makes the train tracks impassable, you still have an infrastructure problem and it's going to result in reliability numbers for some box in the grid architecture being too optimistic. Ditto coal, since many people didn't realize coal piles (which trap water) can freeze.
And the typical way to burn coal in a power plant is to pulverize it very finely and blow the powder into the combustion chamber. Pulverization and blowing require energy, which is generally tapped from the plant's product itself. But if the plant is offline altogether, you need startup power from another generator, which is usually supplied via the grid. But it can also be supplied by onsite auxiliary generators, which may have their own, different environmental susceptibility (see below). So then part of the grid engineering involves how to restart failed generators. It turns out the behavior of the generators has to factor into transmission grid engineering, and it's often a more complex problem than originally believed.
For my critical computer systems, I have two big Cummins diesel skids on the roof (for noise reasons). It's literally the case that we could lose weeks of work if the power to our supercomputers fails unexpectedly. When our sensors detect something sketchy in the line power, it automatically fires up the diesels. We have a 2000-liter tank in the basement and a 60-liter "day tank" on the roof. (You can only keep a certain amount of combustible fuel on an upper floor.) A pump tops off the day tank automatically. We have a giant bank of lead-acid batteries that can run the critical circuit for 30 seconds while the diesels come up to speed, if the line power fails altogether.
Every Monday morning our ops supervisor presses the test button on the sensor, which simulates a power trip (the electrical kind). And the big old diesels rumble to life over everyone's head. We run them for five minutes, which is enough to gather power output statistics and fuel consumption statistics, and test the day-tank supply pump.
But what if one day they didn't?
A few Decembers ago, on a very cold day, the generators started, ran for 15 seconds, and then shut down. As most people know, diesel fuel acquires the consistency of hand lotion at very low temperatures -- an unpumpable goop. But we know this. There are additives that allow it to stay liquid at low temperatures. But it requires the fuel lines, day tank, and main supply tank to be flushed properly when you change over. And we discovered the hard way that it's not always possible to tell whether you've flushed exposed fuel lines correctly. The answer was heated fuel lines, which we didn't previously have. But the question could be what part of that counts as infrastructure? You can draw boxes and lines at a lot of different levels of abstraction and come up with different answers because it all depends on what assumptions you make as part of your abstraction process.