Are photovoltaic cell arrays on a satellite the same that are used within Earth, or is there some difference in their construction given the differing environment in which they are to operate? Does the efficiency/life of a photovoltaic cell change depending upon whether it is within/without Earth's atmosphere?
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1$\begingroup$ This company sells both types, and they have spec sheets, so I would imagine you could do an A/B comparison. One notable difference: their terrestrial photovoltaics are designed to be used with concentrated sunlight (using mirrors). $\endgroup$– Robert HarveyCommented Jul 12, 2012 at 18:51
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2 Answers
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The fundamental mechanism is the same. They are both photovoltaics.
The cells on satellites are far more expensive and efficient. Because satellite launch costs dominate any other cost, you might as well pay for a high-efficiency cell. Terrestrial cells are 10-20% efficient, usually made from silicon. The ones in satellites can be double that efficiency, and are made from triple-junction (recently maybe even quadruple-junction) tandem cells with dozens of layers grown by an expensive epitaxial process (usually MOCVD).
The cells on satellites have different design specs ... weight, radiation-hardness, operating temperature, form factor, etc. They are also optimized for a slightly different spectrum of light, because there is no atmosphere that scatters the blue light etc.
Despite great efforts to make radiation-hard space solar panels, the radiation in space will certainly hurt their lifetime. But it seems not by much. This press release says that Spectrolab has a solar cell that is expected to work almost as well (88% relative) after 15 years in space. By comparison, I know terrestrial silicon solar cells can last well over 30 years, but I don't know exactly how the performance is at the end versus the beginning. By the way, you should keep in mind that the surface of earth can be a pretty tough environment too -- wind, weather, scratches, dirt, reactive oxygen and pollutant gases, heat-cycling, etc.
answered Jul 13, 2012 at 15:27
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Essentially yes they work in the same way.
There are slightly different designs, traditionally the space ones had highest performance because money was no object but because it takes years to space qualify a piece of hardware the gap with the latest cheap tech has shrunk.
The challenge on most spacecraft is mounting and deploying the panels, which usually must fold to fit in the launcher. See ESA description of the Hubble panels
answered Jul 12, 2012 at 19:15