[imrejonk]

The first thing that comes to mind is ENTSO-E's Power Flow Tool. It had a number of simulations of Europe's power grid with typical demand scenario's, prompting you to take care of grid balancing when a power line suddenly failed during peak load.

Unfortunately I just discovered that they removed it from their website somewhere this year. I've asked them to restore it. For now you can play with this copy in the Internet Archive: https://web.archive.org/web/20220124003709/https://www.entso...

[epilys]

The disclaimer is probably unintentionally funny:

   This demonstration tool is not connected to our real grids: therefore you can feel free to go to the limits and test out all constellations that interest you.