How do I find out what sort of power plants provide my specific area?

Okay, I am still trying to get my understanding down -

Assuming that electricity flowed evenly between grids and within them (as Chronos put it, was “homogeneous and isotropic”) then still no, I think, not just related to distance (or really inverse of distance). It would at most be related to the inverse of the square of the distance. And then transmission losses would need to be factored in. That means I am getting very little indeed from any plant any appreciable distance away compared to plants much closer.

And even using the analogy of “a big water reservoir” it still does not hold. My exposure to the water from creek A is effected not only by my distance from it but also by how much water is being sucked out right next to it. If we really wanted to go with the fluid analogy then flow with variously sized sources of production and demand located in various areas can create some very chaotic patterns, not so simple to model. But I’ve got to think the nature of the pipes and of load balancing as an active process makes it not really work like that.

Using my near West Chicago suburb example, the fact that the coal plants are more within the city means that much of that electricity is sucked off before it has a chance to diffuse throughout “the reservoir” - unless they routinely produce a large excess of local demand.

In any case my original question was answered as well as is possible and I appreciate the information provided.