How do we actually compute what happens inside a power grid?
Power grids are huge, non‑linear systems that have to respect very real physical limits. In this lunch lecture, we explore how to compute voltages and currents along transmission lines, why this is harder than it looks, and how numerical methods from mathematics and computer science are used at grid scale. Starting from basic circuit theory, we connect it to large-scale power‑flow calculations used in practice, discuss their computational challenges, and compare common industry approaches with a more scalable, model‑based solution. The talk bridges mathematics, numerical methods, and software engineering, with a concrete example using open‑source tools—showing how ideas from math and computer science directly impact power system analysis.