Silicon solar cells could slash satellite power hardware costs by up to 90%, according to a new study led by the University of Surrey published in the journal Acta Astronautica. Researchers found that substituting standard space solar cells with advanced silicon versions reduces spacecraft solar weight by about half while cutting prices from hundreds of dollars per watt down to tens of cents.
How Silicon Slashes Satellite Power Costs
For decades, space hardware has depended on triple-junction cells made with gallium, indium, and germanium. According to University of Surrey data, these traditional components cost between $250 and $450 per watt. Silicon offers a stark contrast, with raw materials priced at a few dollars per kilogram compared to thousands per kilogram for gallium and germanium.
As of November 2025, market figures cited in the review show the three main silicon designs average well below a dollar per watt: PERC cells sit at $0.275 per watt, TOPCon cells at $0.285 per watt, and heterojunction cells at $0.39 per watt. Performance has climbed concurrently. Silicon heterostructure cells have reached 27.8% efficiency, while perovskite/silicon tandems have hit 34.85% efficiency.
Modeling Realistic Spacecraft Setups
To measure practical efficiency and savings, the Surrey research team modeled two distinct spacecraft configurations. They tested one side of a 3U CubeSat, which measures roughly the size of a large loaf, alongside a Micro Sat built by Surrey Satellite Technology Limited (SSTL), an organization that co-funds the lead author’s PhD and supplied the spacecraft data.
Even after factoring in the cost of protective space-qualified glass required for orbit, the study recorded total savings of roughly 85% to 90%. The findings reveal that once silicon cells are placed behind space-qualified shielding, the coverglass represents the primary expense of the array.
Did you know? From 1958 to 1977, silicon served as the standard solar-cell material for spacecraft. Gallium arsenide cells eventually displaced it due to better efficiency and radiation resistance before triple-junction cells took over the market.
Overcoming Radiation Challenges in Orbit
The primary hurdle for widespread silicon adoption involves radiation shielding rather than raw manufacturing costs. Because coverglass dominates the expense of a silicon array, engineering a cell that natively resists radiation better can change manufacturing priorities.
“The interesting finding for us was not that silicon is cheaper but where the remaining cost sits,” said Tommy Richards, a Ph.D. student focused on future space solar cell technology and the review’s first author, via the University of Surrey. “Once you put silicon cells behind space-qualified glass, the glass is what you are paying for. That changes what we should be working on.”
Richards noted that if engineers can make the cell tougher against radiation, they can utilize thinner glass or substrates. That shift cuts both cost and weight simultaneously, reframing the engineering challenge.
Broader Impacts on Aerospace and Earth Services
Dropping the mass of satellite power systems frees up crucial room on spacecraft for extra fuel or scientific instruments. Lighter and cheaper satellites lower the financial barrier for companies and governments aiming to expand essential infrastructure.
Services relying on orbital hardware—such as weather forecasting, communications, navigation, and Earth monitoring—stand to benefit from lower deployment costs. These expanded networks aid cities in responding to extreme weather, supporting agriculture, and improving emergency planning.
Frequently Asked Questions
Why did spacecraft stop using silicon solar cells previously?
Spacecraft shifted away from silicon between 1958 and 1977 because gallium arsenide cells offered better efficiency and radiation resistance.
How much do silicon solar cells cost compared to standard space cells?
Traditional triple-junction space cells cost between $250 and $450 per watt, whereas modern silicon designs average roughly 28 to 39 cents per watt.
What is the main driver of cost for silicon arrays in space?
According to University of Surrey researchers, the protective space-qualified coverglass accounts for the majority of the expense once silicon cells are prepared for orbit.
What efficiencies have modern silicon cells reached?
Silicon heterostructure cells have achieved 27.8% efficiency, while perovskite/silicon tandem cells have reached 34.85% efficiency.
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