Kardashev scale

The Kardashev scale is a general method of classifying how technologically advanced a civilization is, first proposed in 1964 by the Soviet astronomer Nikolai Kardashev. It had three categories, based on the amount of usable energy a civilization has at its disposal and increasing logarithmically:Type I — A civilization that is able to harness all of the power available on a single planet, approximately 1016 W. The actual figure is quite variable; Earth specifically has an available power of 1.74×1017 W (174 petawatts). Kardashev's original definition was 4×1012 W. (Kardashev had originally defined Type I as a "technological level close to the level presently attained on earth", "presently" meaning 1964.)Type II — A civilization that is able to harness all of the power available from a single star, approximately 1026 W. Again, this figure is variable; the Sun outputs approximately 3.86×1026 W. Kardashev's original definition was 4×1026 W.Type III — A civilization that is able to harness all of the power available from a single galaxy, approximately 1036 W. This figure is extremely variable, since galaxies vary widely in size. Kardashev's original definition was 4×1037 W.
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