I agree with you that the next big stress test is going to be on the electricity grid. The stressor in my opinion is going to be the climate change. More and more countries are going to switch into alternative energy sources. These new energy sources won't be as easily to manage in size as the coal or atom power plants. For example wind can't be controlled, we can only harvest it  if it's there. So once all the old power plants go offline we will see a higher variance.