The authorities blame unexpected storms, tree branches falling on high-voltage power lines (as in the Italian example) and other acts of nature.

ECONOMIST: Why do the lights keep going out?

Outages that used to last a few hours now can drag on for the better part of a week as repair crews contend with flooding, downed trees and snapped high-voltage power lines across vast regions.

FORBES: Preparing The Grid For The Next Superstorm

That is the reason why the current emphasis in China is on the construction of 500kv extra-high-voltage lines and long-distance power transmission.

FORBES: Cracking China's Power Sector

Infineon also provides the thyristor chips that allow transformers to handle high-voltage direct-current power lines.

FORBES: Magazine Article

Fort Knox began talking about solutions with Nolin Rural Electric Cooperative, which maintains the high-voltage lines bringing power to the base.

FORBES: Magazine Article