Rock Street, San Francisco

I-V
Characteristics The I-V Characteristics is a curve between current and voltage.
The area under the I-V curve shows the maximum power that is produce under
operating at maximum current and maximum voltage. The area decreases with
increase in solar cell voltage due to its increase in temperature.

We Will Write a Custom Essay Specifically
For You For Only \$13.90/page!

order now

Fig.1

The maximum power point can be obtained by plotting the
hyperbola defined by V*I= constant.

Abservation table:

The performance of PV modules is obtained at different irradiance level and intensity. For this above two observations are taken. For radiation and voltage intensity, current and power are calculated and for a given maximum power voltage is obtained. That the corresponding IV characteristics are shown above show Pmax for different radiation levels. More irradiation the more power output of PV module is.

Fig.2
Shows the current vs voltage curve at various irradiance levels and the
corresponding maximum power points.

An example is mentioned on paper 3. There is one point on the indentation that will generate maximum power below the level of illumination incidents Operating elsewhere another point then maximum power will mean that cell will produce maximum thermal power and less electrical power.MPPTThe voltage at which the PV module can produce maximum power is called the maximum power point. MPPT checking output of PV module and compare with battery voltage then fix what the best power PV modules can do produce to charge the battery. Basically MPPT is dc-dc converters that operate by taking dc to PV modules convert it to ac and then convert to different dc voltage and the current to exactly match the PV module to the battery. MPPT uses a buck or boost converter for operation.

B.   Temperature

Temperature plays a major factor in determining efficiency of solar cells. As temperatures rises the rate of generation of photons increases so as to reverse saturation It is currently increasing rapidly and this reduces band gap. Therefore, this leads to the current but major marginal voltage changes Cell voltage decreases 2.2Mv per degree of temperature rise. These results are experimental proven . Here the temperature acts as negative factors affecting the performance of solar PV. Temperature modules should be maintained at room temperaturein several ways. Solar cells perform better in the cold than in heat climate panels rated 25 ° C. In the summer days temperatures can easily reach 70 ° C or more that means it panel will produce 25% less power compared to it rated 25 ° C so the 100 watt panel produces only 75watts in May / June in most of Pakistan. Solar pannels are tested at STC with irradiance level of 1000W/m2 and 25°C but in real world condition are constantly changing.Observation Table:

Fig.3
Shows the effects on the current and voltage.

C.    Incident Angle

To
check the effect of incident light on the voltage generated an experiment was
performed in USPCAS-E Peshawar lab and the following values were noted.

Observations:  This experiment data shows that short circuit
voltage increases with increase in the angle of incidence upto 90 degree where
it becomes maximum and after that as we further the increase the of incident of
light the short circuit voltage start decreasing. We also noted that the change
in the short circuit voltage is quite small.

Fig.4
shows the curve for the effect of shading on terminal voltage.

Shading mainly affects the circuit connected PV module. Because the current generated by the shaded part is less than compared to the illuminated part. But this time the series Must be the same cells illuminated at this time forcibly shady section of the current to improve the hotspot results and can cause damage of all modules to solve this problem Parallel configuration is used to set the PV module. In parallel the output is not so affected as in the case of the series configuration. Because the current in parallel is not the same All panels but the voltage must be the same. This experimental prove that parallel configuration is better of the series.

CONCLUSION

This paper review the analysis of the
work performed related with the PV module. The factors discussed in this paper
are very important that affect the performance of the PV panel. If these factor
are not considered in installation and working of panel it may drastically
reduce the electrical output power which result in the loss of capital invested
in the project. If these factors are taken care the output and capacity of the
solar power sector can be improved in our country. It is seen that irradiance,
temperature, orientation, tilt angle, shading, dusts are some major factor
affecting panel performance. So adequate technique should be developed to
mitigate these problems.

References:

1)Uspcase
Lab Peshawar.

2) Lijun
Gao, Senior Member, IEEE, Roger A. Dougal, Senior Member, IEEE,
“Parallel-Connected Solar PV System to Address Partial and Rapidly Fluctuating
Shadow Conditions”, volume:56, issue:5,Publication Year: 2009 , Page(s): 1548 –
1556

3) Journal of Solar Energy
Volume 2013 (2013), Article ID 734581,
http://dx.doi.org/10.1155/2013/734581

PV cell Performance with Changing Irradiance and Temperature” ,1 Jan 2013 Page
No. 214-220.

5) Ramaprabha
Modules”. Vol 3,no. 10, 2009

6) Malay Mazumder, Mark
Horenstein, Jeremy Stark, Peter Girouard , Robert Sumner, Brooks Henderson
Omar Sadder Ishihara Hidetaka, Alex Biris, and Rajesh Sharma,
“Characterization of Electrodynamics Screen Performance for Dust Removal from
Solar Panels and Solar Hydrogen Generators”, volume: 49 , issue:4 Publication
Year: 2011 , Page(s): 1-8.