Outside of electricity fundamentals, this book is a great intro on how the grid works: https://www.amazon.com/Electric-System-Nonelectrical-Profess...
Or a shorter alternative: https://www.ucsusa.org/resources/how-electricity-grid-works
Or a shorter alternative: https://www.ucsusa.org/resources/how-electricity-grid-works
One example is capacitor banks, which it spent a few pages on. I'm told that they're more beneficial the closer to an inductive load they're installed, but I was never told why, or given any tools to figure it out why for myself. There's not even a citation.
After reading this book I have a better understanding of how much of the grid I don't understand, but I don't feel like there's any part I understand particularly better.