4 ms·

Max so far is 46%[1], max theoretical is 86.8%[2] Most solar panels are 15% or better. The best residential cells are 22.2%[3], the commercial cells are 25.3%

Max so far is 46%[1], max theoretical is 86.8%[2] Most solar panels are 15% or better. The best residential cells are 22.2%[3], the commercial cells are 25.3%. The theoretical maximum efficiency of single-layer silicon PV cells is ~32%. [1]: https://www.nrel.gov/pv/assets/images/efficiency-chart.png https://www.nrel.gov/pv/assets/images/efficiency-chart.png [2]: https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limit https://en.wikipedia.org/wiki/Shockley%E2%80%93Queisser_limi... [3]: https://us.sunpower.com/sites/sunpower/files/media-library/data-sheets/ds-x22-series-360-residential-solar-panels.pdf https://us.sunpower.com/sites/sunpower/files/media-library/d...

schoen 9y ago
That's awesome. I remember always hearing 10% when I was a kid, which looks about right on that first chart, assuming it takes a few years before things are commercialized. It's terrific to see the march of improvements in efficiency.
deepsun 9y ago
Curious, what is on spacecrafts. Maybe not really efficient at all, because weight and reliability is way more important out there, and also abundance of raw sunlight.
- extrapickles 9y ago
  Usually much better (5-10%) as cost is no object, and they don't have the losses involved with the protective glass that terrestrial applications need. Edit: and they are usually triple junction.
- mlindner 9y ago
  We used triple-junction solar cells on our satellite. If I remember right the cells ran somewhere around $100-$200 per square inch. I don't remember the efficiency, but they were left-over dumped cells that were donated to us by some group at NASA because they "expired" (they're kept under a nitrogen purge because they oxidize slowly and these had a leak, if memory serves, still worked great though) and a few were broken as they are more fragile than glass and are about as thin as a sheet of paper. They glow bright red when you forward bias them which you can use to visually detect dead portions of the cell/damage.
lucb1e 9y ago
> max theoretical is 86.8% I recall hearing the theoretical max was somewhere around 36%, though it could well be my memory is faulty. I think this was from a video from around 2005. Is this "theoretical max" going up over time or do I misremember?
- rsfern 9y ago
  I think 31% is the thermodynamic limit for a single p-n junction, and 86.6 is for an infinite stack of them [0]. I'm not sure whether these limits apply to non-planar geometries. [0]: https://en.m.wikipedia.org/wiki/Thermodynamic_efficiency_limit https://en.m.wikipedia.org/wiki/Thermodynamic_efficiency_lim...
- hwillis 9y ago
  86.8% is for an infinite number of layers with concentrated solar. 33.7% is the max for a single layer p-n junction, which is what most readily available cells are. The most expensive, high efficiency cells, like those on spacecraft, are 3 layer. They are too expensive to be practical on Earth.

schoen 9y ago

That's awesome. I remember always hearing 10% when I was a kid, which looks about right on that first chart, assuming it takes a few years before things are commercialized. It's terrific to see the march of improvements in efficiency.

deepsun 9y ago

Curious, what is on spacecrafts. Maybe not really efficient at all, because weight and reliability is way more important out there, and also abundance of raw sunlight.

extrapickles 9y ago
Usually much better (5-10%) as cost is no object, and they don't have the losses involved with the protective glass that terrestrial applications need. Edit: and they are usually triple junction.
mlindner 9y ago
We used triple-junction solar cells on our satellite. If I remember right the cells ran somewhere around $100-$200 per square inch. I don't remember the efficiency, but they were left-over dumped cells that were donated to us by some group at NASA because they "expired" (they're kept under a nitrogen purge because they oxidize slowly and these had a leak, if memory serves, still worked great though) and a few were broken as they are more fragile than glass and are about as thin as a sheet of paper. They glow bright red when you forward bias them which you can use to visually detect dead portions of the cell/damage.

lucb1e 9y ago

> max theoretical is 86.8% I recall hearing the theoretical max was somewhere around 36%, though it could well be my memory is faulty. I think this was from a video from around 2005. Is this "theoretical max" going up over time or do I misremember?

rsfern 9y ago
I think 31% is the thermodynamic limit for a single p-n junction, and 86.6 is for an infinite stack of them [0]. I'm not sure whether these limits apply to non-planar geometries. [0]: https://en.m.wikipedia.org/wiki/Thermodynamic_efficiency_limit https://en.m.wikipedia.org/wiki/Thermodynamic_efficiency_lim...
hwillis 9y ago
86.8% is for an infinite number of layers with concentrated solar. 33.7% is the max for a single layer p-n junction, which is what most readily available cells are. The most expensive, high efficiency cells, like those on spacecraft, are 3 layer. They are too expensive to be practical on Earth.