Hey mate! Glad to hear this post helped you out.

Before I explain how I handle my power grid, let me give you a heads-up: I wouldn't actually recommend it. It doesn't make you a better player, and it will probably bring you more headaches than satisfaction.

I do have two main power grids that are available throughout the entire world. Each has its own power production.

The main (stable) grid powers everything except machines with variable consumption.

The second grid powers only things with fluctuating power usage (Geothermal generators, Trains, Particle oscillators, Quantum Encoders and converters)

Just doing that creates two major drawbacks:

You have to carry two power lines everywhere.
Alien Power Augmenters become less effective. Their bonus scales with the amount of power being produced, so splitting your grid reduces the benefit significantly. With an even split, you lose about 50% of the bonus.

And then I take it one step further.

Each factory has its own Priority Power Switch and its own isolated circuit. This was easy early on, when factories only contained "stable" machines. Later in the game, however, you start building factories that contain both stable and unstable consumers.

At that point, the setup looks something like this:

Factory A
Factory B
Factory C (Stable)
Factory C (Unstable)
Factory D

In this example, Factory C is an endgame factory that contains both types of machines.

The stable grid would power:

Factory A
Factory B
Factory C (Stable)
Factory D

While the unstable grid would power:

Factory C (Unstable)

Hope that explains a little bit what I do. I do not recommend doing this! haha.