• Cover. Glass or other radiation-transmitting material.
• Heat removal fluid passageways. Tubes, ﬁns, or passages which containing fluid from the inlet to the outlet.
• Absorber plate. Flat, corrugated, or grooved plates are attached to tubes, ﬁns, or passages. A special attachment is the embedded ﬁxing shown in the detail of Figure 3.2. The plate is usually coated with a high-absorbent, low-emittance layer.
• Headers or manifolds. The pipes and ducts which discharge the fluid.
• Insulation. Reduce the heat loss from the back and sides of the collector.
• Container. The casing surrounds the upper parts to protect them from dust, moisture
Solar energy …show more content…
It can indicate that the amount of the current and voltage depend on the value of solar cell irradiance.
I=I_l-I_0 〖(e〗^(qV/kT)-1) 1
Where I_l stands for the cell current caused by the photons, q=1.6×〖10〗^(-19) Coul, k=1.38×〖10〗^(-23)j/K and T is the cell temperature in K. To determine the short current circuit in the PV cell, simply set the V = 0 in the equation above. After simplifying, the equation isI=I_l . It can conclude that the cell current is directly proportional to the cell irradiance. If the cell current is obtained at the standard test conditions, GO = 1 KW/m2 at AM 1.5, then the cell current at any other irradiance, G, is
I_l (G)=(G/G_0 ) I_l (G_0) 2
Voc, the open circuit voltage, is the voltage measured with an open circuit. It is measured with the module in full sunlight using a voltmeter attached to the positive and negative leads of the module. On the I-V curve, this is the point where the curve crosses 0 amps. This is the maximum voltage that the module can produce on a sunny day …show more content…
Most frequent condition are: irradiance 100mw/cm2, standard reference AM1.5 spectrum, and temperature 25℃ . The Table upper also is shown different solar cell module types about their maximum efficiency and commercial efficiency. From comparing the data, it can indicate that the commercial efficiencies are almost half of the experiment efficiency.
Temperature and irradiance effects
In practical applications, solar cells do not operate under standard conditions. The two most important effects, temperature, and irradiance should be considered.
Effect of irradiance
The intensity of solar radiation influences the output of the solar cell module significantly. The below Figure 5 show that the module output is directly proportional to the solar irradiance. It can find that the module output will less to half value and the voltage will also be lower when the irradiation reduces 50 percentage compared with the left and right picture. The bottom I-V curve indicates that the current drop approximately 50 percent while the radiation intensity reduces to 50 percent . As we have seen, the light-generated current is proportional to the flux of photons with above bandgap energy. Therefore, the amount circuit current of a solar cell is directly proportional to the irradiance. The voltage