Silicon solar cells could cut satellite power costs by up to 90%

(SpaceEnergy) Modern silicon solar cells could cut satellite power-system costs by up to 90% at beginning of life while halving solar-cell mass, according to a University of Surrey-led review.

Researchers compared modern silicon technologies with the triple-junction gallium-indium-germanium cells widely used in space. Triple-junction cells cost about $250-$450/W, while terrestrial silicon cells cost tens of cents per watt, the university said.

Modelling a 3U CubeSat panel and a Surrey Satellite Technology Limited microsatellite showed cost savings of 85-90% after including space-qualified coverglass. Silicon heterojunction cells delivered specific power of about 920-1,000W/kg, compared with 455-505W/kg for triple-junction cells.

The trade-off is lower beginning-of-life power per unit area and weaker radiation resistance. The review found silicon produced about 28% less power for a given area initially and was around 2.6 times less radiation-resistant for a given coverglass thickness.

The researchers said the manufacturing scale of silicon could become particularly important for space-based solar power, where proposed systems could require photovoltaic structures kilometres across and gigawatts of generating capacity.

“If we are going to collect solar power in orbit and send it back to Earth, we will need solar cells by the square kilometre,” University of Surrey lecturer Jae Yun said. “Silicon is the one material we already know how to make on that scale.”

The review identifies radiation, vacuum-ultraviolet exposure and orbital thermal cycling as areas requiring further testing.