In today's list of things that are apparently incomprehensible, demand can be shifted by more than the length of one transmission line. Consider three cities a

In today's list of things that are apparently incomprehensible, demand can be shifted by more than the length of one transmission line. Consider three cities and four generators with a 300km transmission line between each. g1--C1--g2--C2--g3--C3--g4 Each generator normally sends 1GW into each transmission line, but today g1 produces twice as much amd g4 produces nothing. g1 powers C1, g2 powers C2 and g3 powers C3. The electricity must have teleported 1800km, it's the only explanation. Otherwise you'd have to consider an idea like some kind of 'network' of 'transmission' and that you need to model an entire system with nuance rather than pretending each element is completely isolated and has a constant load with no variation. Similarly energy can go through more than one interchange. Electrons don't have a little ttl counter, it just reduces efficiency some.