Homework Help: Efficiency calculation for solar cells

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1. May 21, 2015

ExoP01

1. The problem statement, all variables and given/known data
Hi!
I have a problem with the following problem:
Calculate the efficiency of the solar cells with the characteristics given in the table below
Power (28 degrees, BOL): 300 W/m2 Absorptance: <91 , emittance: >82. Reliability: 0.999 . Mass: 2 kg

2. Relevant equations
I know that the equation for efficiency calculations is:
(maximum eficiency) = (maximum power output)/ (incident radiation flux * Area of the array)

But I don't know what to do since the absorptance and emittance is included. Please, help me :/
3. The attempt at a solution
I assumed that the area is I m2. The power output is given above.
I divided the emittance with absorptance ...And now I'm stuck

2. May 23, 2015

Kyouran

I don't think you need to take into account the absorptance and emittance in the calculation of the efficiency. If you include the absorptance, you can find the absorbed flux, but as you said in the formula above, it is the INCIDENT flux that you need. You don't need to use the absorptance or emittance.