Type I: A civilization that is able to harness all of the power available on a single planet — has approximately 1016 or 1017 Watts available. Earth specifically has an available power of 1.74 ×1017 W (174 peta watts, see Earth’s energy budget). Kardashev’s original definition was 4 ×1012 W — 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 4 ×1026 W. Again, this figure is variable; the Sun outputs approximately 3.86 ×1026 W. Kardashev’s original definition was also 4 ×1026 W.
Type III: A civilization that is able to harness all of the power available from a single galaxy, approximately 4 ×1037 W. This figure is extremely variable, since galaxies vary widely in size; the stated figure is the approximate power output of the Milky Way. Kardashev’s original definition was also 4 ×1037 W.
Type IV: A civilization that has harnessed the power of its supercluster, or “the largest gravitationally bound structure it originated in.” For the Local Supercluster, this would be approximately 1042 W. Dr. Michio Kaku has discussed a type IV civilization, which could harness “extragalactic” energy sources such as dark energy, in his book Parallel Worlds.
Type V: A civilization that uses the entire resources of its respective universe.
“We had no equals. We controlled the fundamental forces of the entire universe. Nothing could communicate with us on our level.”