How space station solar wings make power

The space station's huge solar wings carry hundreds of thousands of silicon cells that turn sunlight into electricity. Motorized joints keep turning the wings to face the sun as the station circles Earth, because power falls off with the cosine of the tilt angle. For up to about 36 minutes of every 92 minute orbit the station is in Earth's shadow and runs on batteries charged during the sunlit part.

Controls

Labels

Animation speed

Wing angle away from the sun

Solar cell efficiency

In Earth's shadow

Step through it

Wings of cellsEach wing holds two long blankets of silicon solar cells, about 32,800 cells per wing. The station has eight wings in all; four are shown here.
Pointing at the sunPanels collect the most power when sunlight hits them straight on. At 60 degrees off they deliver only half as much.
Rotating jointsLarge joints turn the whole set of wings once per orbit while smaller joints tilt each wing, keeping the cells facing the sun as the station circles Earth.
Orbital nightFor up to about 36 minutes each orbit, Earth blocks the sun. Batteries charged in daylight carry the station through.

The solar power formula

Electrical power = cell area x sunlight intensity x efficiency x cos(angle). Above the atmosphere sunlight delivers about 1,361 watts per square meter. This model assumes about 210 square meters of active cells per wing, roughly 32,800 cells of 8 by 8 cm.

Real output is lower than this ideal number because of wiring and conversion losses, cell aging from radiation, and temperature. The station's arrays were designed for roughly 84 to 120 kilowatts in total.

Try it: leave efficiency at 14 percent and slide the angle from 0 to 60 degrees. One wing drops from about 40 kW to 20 kW. Then raise efficiency to 30 percent, closer to modern multi-junction cells, and the same wing more than doubles its output.

Why orbit average matters

The station only collects power for about 56 minutes of each 92 minute orbit. The orbit average readout spreads the sunlit output over the whole orbit, which is what the batteries and loads have to live within.

Where Avid uses this

Avid's agrivoltaics work faces the same trade between panel angle, sunlight and output, but on farmland where crops share the light.

Sources

Solar Arrays on the International Space StationNASA
International Space Station Electric Power System (fact sheet, archived)University of North Texas Libraries web archive (NASA Glenn)
The Electric Power System of the International Space Station: A Platform for Power Technology Development (NASA/TM 2000-210209)NASA Technical Reports Server

How to cite this model

Avid Solutions International. (2026, November 11). How space station solar wings make power [Interactive 3D model]. Avid Field Lab. https://avidsolutionsintl.com/explore/iss-solar-array

Last updated November 11, 2026

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