Storage
How energy is kept in reserve beyond Earth. Batteries, fuel cells, flywheels, and other buffers that bridge generation and demand.
Why storage is the limiting factor
Spacecraft power systems are defined by the gap between when energy is generated and when it is consumed. A satellite in low Earth orbit enters eclipse every 90 minutes and needs battery storage to survive the 35-minute darkness. A lunar surface outpost faces a two-week night where no solar power is available, requiring either nuclear power or energy storage measured in hundreds of kilowatt-hours. State-of-the-art lithium-ion batteries at 200 Wh/kg are adequate for eclipse cycling but fall far short of the specific energy needed for extended surface operations.
The daily analysis stream examines the storage technologies that could close this gap: regenerative fuel cells that store hydrogen and oxygen for lunar night survival, next-generation battery chemistries like lithium-air that promise theoretical densities above 3000 Wh/kg, and the trade-offs between round-trip efficiency, cycle life, and specific energy that determine which technology fits which mission.