Mid 20th Century (1950)

Parent universe: Reality

Value: 0.65
Min: 0.55
Max: 0.70
Confidence: CalculatedGuess

References:

88 k TWh in 1980.

Value: 1.15e9
Min: 1.1e9
Max: 1.2e9
Confidence: Canon

References:

Quick Wikipedia research. Error bars guestimated.

Diesel engines, huge industrial plants, coal power plants.