[rdefayette]

Originally Posted by RedDevil

The grid breaks down because it can break down. There has only been invested so much in it. Once it becomes the only system of redistributing energy, time and money must be spent to make it disaster proof.

In Holland the low voltage grid is >99,9% underground and even the high voltage lines are slowly but steadily moving out of sight.
As a result grid failures are quite infrequent over here; one of the last big ones was caused by an Apache helicopter...

Would it be a stupid idea to put all the main electric lines in the southern coastal area and tornado alley underground?

Underground lines are great so long as the system is watertight. Florida, for example, just had Hurricane Irma go through with a LOT of flooding from the storm surge. 2 problems arise with Florida in particular when it comes to "the grid"/power distribution of any kind. 1) over head lines can be brought down by high winds and trees falling during a hurricane. 2) The storm surge and subsequent flooding will cause just as much if not more damage than the winds themselves due to improved construction techniques/building codes and hurricane "resistant" building products. The problem with the underground lines in coastal regions, such as Florida, that see any type of frequent flooding is the underground electric distribution system does NOT fare too well when saltwater is introduced into the equation. Buried/underground transformers (even those placed on ground level pads) electric lines/cables, etc and saltwater are a combination that that leads to power outages if not during the storm but "short"ly (pun intended) thereafter.