Solar Sail
Overview
Solar Sails are consumable components used to build Dyson Swarms and, later, the shell segments of a Dyson Sphere. They are launched from an 
A Solar Sail has a base lifespan of 5400 s (1.5 hours), which can be extended to 9000 s (2.5 hours) by researching Solar Sail Life upgrades. While in the swarm, sails are temporary and will disappear when their lifespan ends unless they are continuously replenished. Once a sail is absorbed into a designed Dyson shell, however, its lifespan becomes indefinite. This makes shell construction the permanent use of Solar Sails, while swarm use is a temporary power solution.
The power output of Solar Sails scales with the star’s luminosity. Around a star with luminosity 1.0, one sail generates 36 kW, for a baseline energy yield of 194 MJ over its full life. Unlike real-world orbital power systems, the output does not depend on distance from the star. When sails are used in a swarm, their total output depends on how many are currently alive in orbit, which in turn depends on how quickly they are being produced and launched.
Because of this limited lifespan, swarm power is fundamentally a throughput problem: if sails are not manufactured and launched fast enough, the swarm will shrink until it stabilizes at the rate your production line can sustain. A continuously firing EM-Rail Ejector can maintain up to 1800 Solar Sails in orbit at the default lifespan, producing 64.8 MW around a star with luminosity 1.0.
- Solar Sails are best treated as a consumable power buffer before a full Dyson Sphere is completed.
- Their value rises and falls with star luminosity, so brighter stars yield more power from the same number of sails.
- Swarm power is only useful if you can keep replacing expired sails at the needed rate.
- Once a shell design exists and enough Small Carrier Rockets have built out the frame, launched sails will be requisitioned into the shell automatically, turning them into permanent structure rather than temporary orbiting assets.
