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Author Topic: How is photon number related to wattage of a solar panel?  (Read 8594 times)

Geezer

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How is photon number related to wattage of a solar panel?
« Reply #25 on: 10/12/2011 08:57:22 »
There is actually a perfectly convenient and respectable SI alternative to millibarn.

1 barn = 1.E-28 m2, therefore 1 millibarn = 1.E-31 m2

1 fm = 1.E-15 m, therefore 1 fm2 = 1.E-30 m2 = 10 millibarn

Yes, but how many sheepies would that hold?

damocles

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How is photon number related to wattage of a solar panel?
« Reply #26 on: 10/12/2011 13:55:25 »
There is actually a perfectly convenient and respectable SI alternative to millibarn.

1 barn = 1.E-28 m2, therefore 1 millibarn = 1.E-31 m2

1 fm = 1.E-15 m, therefore 1 fm2 = 1.E-30 m2 = 10 millibarn

Yes, but how many sheepies would that hold?

approximately 0.314 attosheep

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acsinuk

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How is photon number related to wattage of a solar panel?
« Reply #27 on: 11/12/2011 02:59:49 »
Shrunk
Have just looked up Oliver Boyd and found that a 1 kWh is equivalent to 2.247 * 10^25 electron-volts which means that as average light photons have 1.1 eV each then 2*10^25 is good aproximation for a one square metre PV panel which gets 1 kW peak at noon on equator after allowing for third haze reduction. The power is received per square metre but to change it into energy we must multipy by time.  So each photon is not a magic massless ray but a volume of 3 dimensional magnetic flux energy which is absorbed at the surface of the PV cell.
CliveS

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How is photon number related to wattage of a solar panel?
« Reply #27 on: 11/12/2011 02:59:49 »