Also known as a Type 2 civilization · K2
A Type II civilization — a stellar civilization — no longer relies on the fraction of sunlight that strikes a single planet. It captures the total energy output of its parent star, on the order of 10²⁶ watts, turning the star itself into infrastructure.
On the Kardashev scale, a Type II civilization commands roughly ten billion times more energy than a Type I. To collect that much power, theorists imagine a Dyson swarm: a vast cloud of orbiting collectors and statite mirrors that surrounds the star and intercepts nearly all of its radiation.
At this scale, engineering happens on the level of the star system. Concepts include stellar engines that slowly move a star, star-lifting to mine stellar material directly, and antimatter factories powered by raw stellar output. A Type II civilization would have a permanent, system-wide presence rather than living on a single world.
The physics is demanding but not forbidden by known laws. The main barriers are material and logistical — assembling enough collectors, dissipating waste heat, and coordinating construction over centuries. A civilization that crosses this threshold has effectively made its star its battery.
A Type II (stellar) civilization on the Kardashev scale can harness the entire energy output of its star — about 10²⁶ watts — typically by surrounding it with a Dyson swarm of energy collectors.
A Dyson swarm is a proposed megastructure made of countless independent collectors and mirrors orbiting a star, capturing a large fraction of its light. It is the most physically plausible version of a Dyson sphere and the signature project of a Type II civilization.
Around 10²⁶ watts — roughly 3.8 × 10²⁶ W for a Sun-like star. That is about ten billion times the power of a Type I civilization.
Estimates suggest a few thousand years, assuming continued growth in energy use and the ability to build large-scale structures in space.
