Popis: |
The current and voltage of a solar cell can be measured by optimal load method. However, this method does not automatically adjust the load to ensure maximum power output as solar irradiance varies, hence power output losses. This study investigated the losses in power output that occur in solar cell when characterised by optimal load method. This was done by exposing the solar cell at different illumination intensities (between 300 and 1,000 W/m2 in the interval of 100 W/m2 ) and measuring current and voltage using Keithley Source-meter as well as optimal load (102 mΩ) method. From current and voltage, maximum power output of the solar cell for both methods were calculated and compared. It was found that the power output calculated from optimal load method (102 mΩ) were in good agreement with those from Keithley 2340 Source-meter only between 500 to 700 W/m2 . As a result, the solar cell lost between 1.3 to 33.4% of its maximum power when illumination intensities were outside the operating range of the optimal resistive load. Conversely, when a resistive load of 45 mΩ (which is not optimal) was used, the solar cell lost between 0.8 to 81.4% of its maximum power at various illumination intensities. |