Solar Panels On Spacecraft - Uses

Uses

Solar panels on spacecraft supply power for 2 main uses:

• power to run the sensors, active heating and cooling, and telemetry.
• power for spacecraft propulsion -- electric propulsion, sometimes called solar-electric propulsion. See also energy needed for propulsion methods.

For both uses, the figure of merit of the solar panels (and RTGs) is the power generated per kilogram, as an upper limit of the power the spacecraft has at its disposal per kg spacecraft (including solar panels).

To increase the power generated per kg, typical solar panels on spacecraft use close-packed solar cell rectangles that cover nearly 100% of the sun-visible area of the solar panels, rather than the solar wafer circles which, even though close-packed, cover about 90% of the sun-visible area of typical solar panels on earth. However, some solar panels on spacecraft have solar cells that cover only 30% of the sun-visible area.