Branch : Computer Science and Engineering
Subject : Fundamental of Electronic Devices
Unit : Basic Electronics
Solar Cell- I-V Characterstics
I-V Characterstics:
- Figure 2 shows the fourth-quadrant portion of a solar cell characteristic, with Ir plotted upward for convenience of illustration.
- The opencircuit voltage Voc and the short-circuit current Isc are determined for a given light level by the cell properties.
- The maximum power delivered to a load by this solar cell occurs when the product VIr is a maximum.
- Calling these values of voltage and current Vm and Im, we can see that the maximum delivered power illustrated by the shaded rectangle in Fig. is less than the IscVoc product.
- The ratio ImVm/IscVoc is called the fill factor, and is a figure of merit for solar cell design.
Application:
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Applications of solar cells are not restricted to outer space.
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It is possible to obtain useful power from the sun in terrestrial applications using solar cells, even though the solar intensity is reduced by the atmosphere.
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Current worldwide total power generation capability is -15 TW and corresponds to an annual energy usage of -500 quads (1 quad = 1015, or a quadrillion, BTU), with an annual increase of 1-2%.
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Of this, -80% comes from fossil fuels (oil, natural gas,and coal), which will be exhausted in several hundred years.
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In addition, C02 emissions and global warming have spurred a renewed interest in "green" sources of energy such as photovoltaics, even though the current installed capacity is only about 1 GW.
About 1 kW/m2 is available in a particularly sunny location (translating to about 600 TW potentially available worldwide), but not all of this solar power can be converted to electricity.