Why are Solar Panels used in Satellites & Spacecrafts?

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Sep 19, 2022

Spacecrafts or satellites that orbit around the earth, near the sun are powered by solar energy. Solar panels are fitted on these satellites or spacecraft and are economical and conserve space and energy. That’s why they are preferred over batteries for operation. Space-based solar panels can generate up to 2000 gigawatts of power constantly because these satellites are primarily in the earth’s shadow for about 72 minutes. Solar panels are used to generate power to run the sensors, provide heating & electrically power spacecraft propulsion which is required to rectify or adjust the path on which a satellite or a spacecraft follows.

Solar panels are installed in form of arrays. Solar arrays consist of thousands of solar cells which are made of different materials. Altogether there are 4 sets of arrays that can generate 84-120 kW of electricity. Each solar array is 112 feet long & 39 feet wide.

NASA & its significant partners have developed a method of deploying solar panels in space as they cannot be launched from the earth directly. It will result in the panels shredding & breaking apart before it reaches orbit. Hence “Blanket Method” was created in which the solar panels are folded into a compact size for delivery in space and then spread out or deployed to their full size once in orbit.

Once the satellite or the spacecraft is in orbit, ground controllers on earth send commands to deploy the blankets to their full size. Solar arrays are rotated and adjusted to face the sun by using Gimbals to provide maximum power to the satellite by making the panels face the sun.

Sunlight or solar radiation consists of different electromagnetic spectrums. They are visible spectrum (46%), infrared spectrum(47%) & UV spectrum (7%). The materials which are used to make these panels determine how much solar energy and its different spectrums it can absorb efficiently to create electricity.

Solar panels can last for around 25 years before they start to degrade over time. The degradation of solar panels takes place because they are in direct contact with an unadulterated form of solar radiation. Panels expand & contract over time due to the heat which is subjected to them by the sun. This expansion & contraction results in the formation of micro-cracks which will result in degradation in the overall performance of solar panels. The lower the degradation rate, the better the panel would work and generate more electricity, else the lifetime of a solar panel will reduce to 8-10 years and provide low efficiency due to degradation.