. During your lab, your TA measured the current without load from a laboratory- calibrated ClS cell under at illumination conditions, and you recorded this measured current in Table 5 of your lab procedure. This measurement can be used to determine the absolute efficiency of your solar cells. a. When illuminated by a total solar photon ux of 1038 W m'2 under laboratory conditions, the TA's solar cell produced a current without load of 66.1 mA. Assuming that the current without load for this type of solar cell is proportional to the ux of solar photons, use your TA's measurement of the CIS Current without load in Table 5 of your lab procedure to determine the actual solar photon ux for a at surface at the top of the Geology Building in W m'2 at the time you made your measurements. b. Under the best circumstances, the maximum power that a solar cell can produce can be approximated as Pmax =Vm1x Icwl, where Vcwl and [CW1 are the Voltage without load and the Current without load values that you measured during the lab. Calculate Pmax for the Amorphous, CIS and Monocrystalline cells for Flat illumination conditions from your data in Table 2 of your lab procedure. c. Use the surface areas of the solar cells and your results from 3a and 3b to calculate the maximum potential efficiencies of your Amorphous, CIS and Monocrystalline cells and compare your values with published efciencies for these types of cells. UCLA EPSS 101 - Lab 5 - Procedure Table 2 - Flat Amorphous CIS Monocrystalline Voltage without load 3. 86 V 4. 28 V 6. 23 V Current without load 0. 02 A 0.02A 2. OSA Voltage across 1kQ 3. 345 V 4. 09 5 V 5. 94+ v 4. Leaving the EB where it is, have one partner use a hand and cover each solar cell in a shadow while you make your measurement. Now, only diffuse sunlight enters the solar cells. Repeat the measurements taken in Step #1 in this new lighting configuration. Record your measurements in Table 3. Table 3 - Shadow Amorphous CIS Monocrystalline Voltage without load 3. 109 3.16 5.115 Current without load 0 . 0 18 0.00 9 0 . 37 Voltage across 1kQ 2.85 2. 25 1.5 5. Have one partner tilt the EB so that the solar cells are facing directly towards the sun, with no shadows falling on it. Repeat the measurements taken in Step #1 in this new lighting configuration. Record your measurements in Table 4. Table 4 - Direct Sunlight Amorphous CIS Monocrystalline Voltage without load 3. 745 4. 362 4. 28 Current without load 0. OZA 0. 026 # Voltage across 1kQ 3.2 1 1. 24 V 4. 24 V 6. Get data from the pre-calibrated CIS solar cell on EB#1 from your TA. You will use the current without load measurements in the calibrated cells to later determine the incident solar radiation on the roof during your lab section. Record these values in Table 5. Table 5- Calibrated Cell Measurements Calibrated CIS Current without load 83. GMA 2