Related anecdote: a friend of mine is an engineer that builds and operates glass factories all around the world, mostly producing bottles for beer, wine, and liquor. One of his company's factories was in Venezuela, and while he was there working, Chavez et co decided to nationalize that industry because they were "forcing unfair labor conditions."

The company rushed to get every American out of the country before the military showed up and seized control of the factory.

But as it turns out, making glass is hard and requires constant tuning and adjustment. None of the new Venezuelan managers had the expertise needed to continue glass production at anywhere close to the same levels of efficiency and quality. Thus the factory started to lose its ability to produce glass bottles at all.

I can imagine a similar lead-up to this in Venezuela's power industry. Nationalization -> loss of expertise -> loss of efficiency -> national crisis.