insolation and short circuit current equation

zubair

how the insolation is related to short circuit current. How this fomula was made "G = Isc / 1000". where G = solar insolation in watt/m^2 and Isc = panel short circuit current.

BB.

Re: insolation and short circuit current equation

More or less... Say you have a panel with Isc=2.5 amp at 1,000 W/m^2.

Then the true W/m^2 would be:

• W/m^2 = Isc (measured) / Isc@1,000 W/m^2

So, if you measure Isc for a "2.5 amp Isc panel", then:

• W/m^2 = 0.5 amps measured / 2.5 amp Isc per 1,000 W/m^2 = 200 W/m^2

Isc (measuring panel current into a current meter with ~ 0 ohm load) is reasonably proportional to the amount of sunlight hitting the panel (obviously, silicon solar cells have different sensitivity to the sunlight spectrum--so this is not a lab quality measurement).


-Bill

RCinFLA

Re: insolation and short circuit current equation

Isc is directly proportional to insolation but not a direct equal equation without a few more factors.

The size of cell and efficiency effects the result. Temperature effects to a slight degree with more current produced when cell is hot at a 0.03% to 0.05% increase per deg C. It is the size of one primary cell, not how many are connected in series within a panel.

Assuming a good quality mono or poly silicon cell, the current produced for the area of a cell is 32 mA to 35 mA per square centimeter at full sun of 1000 w/m^2.