Did you have a look at the relevant PVCDROM page already? Here it is: https://www.pveducation.org/pvcdrom/solar-cell-operation/effect-of-temperature

The main effects presented there are that (i) the open-circuit voltage decreases for increasing temperature because of the temperature dependence of the (thermally driven) minority currents across the p–n junction and (ii) the short-circuit current increases slightly with temperature since the bandgap energy decreases, so more photons have enough energy to create electron–hole pairs.

Hi

I think it is better to specify the type of the solar cell

These articles will help you

Temperature dependence of solar cell performance—an analysis

Solar Energy Materials and Solar Cells

Volume 101, June 2012, Pages 36-45

https://doi.org/10.1016/j.solmat.2012.02.019

Effect of temperature on internal parameters of solar cell

Materials Today, Volume 33, Part 1, 2020, Pages 732-735

https://doi.org/10.1016/j.matpr.2020.06.079

Temperature Effect on Performance of Different Solar Cell Technologies

J. Ecological Engineering, Volume 20, Issue 5, (2019):249–254

DOI: https://doi.org/10.12911/22998993/105543

The Effect of Temperature Variations on Solar Cell Efficiency.

International Association of Scientific Innovation and Research (IASIR)

Available from: https://www.researchgate.net/publication/284771669_The_Effect_of_Temperature_Variations_on_Solar_Cell_Efficiency#fullTextFileContent

I think this will be useful as well

Temperature Dependent Photovoltaic (PV) Efficiency and Its Effect on PV Production in the World – A Review

Energy Procedia, Volume 33, 2013, Pages 311-321

https://doi.org/10.1016/j.egypro.2013.05.072

Dr Jan-Martin Wagner and Dr Ibrahim M Hamammu thank you for your contribution to the discussion

Temperature effect on the efficiency of photovoltaic cells

The efficiency of photovoltaic cells decreases with increasing temperature. This is because the band gap energy of the semiconductor material decreases with temperature, which means that less energy is required to generate an electron-hole pair. However, this also means that more electrons will have enough energy to jump back into the valence band, which reduces the overall efficiency of the cell.

The temperature coefficient of a solar cell is a measure of how much its efficiency decreases with increasing temperature. It is typically expressed as a percentage loss in efficiency per degree Celsius (°C). For example, a solar cell with a temperature coefficient of -0.5% per °C will lose 0.5% of its efficiency for every 1 °C increase in temperature.

The temperature coefficient of a solar cell varies depending on the type of semiconductor material used. Silicon solar cells have a temperature coefficient of around -0.4% per °C, while thin-film solar cells can have temperature coefficients of up to -1% per °C.

Temperature effect on PV characteristics of solar cells

Temperature also affects the other PV characteristics of solar cells, including the open-circuit voltage (Voc), short-circuit current (Isc), and maximum power point (Pmp).

• Voc: The Voc of a solar cell decreases with increasing temperature. This is because the band gap energy of the semiconductor material decreases with temperature, which means that less energy is required to generate an electron-hole pair.
• Isc: The Isc of a solar cell increases slightly with increasing temperature. This is because the band gap energy of the semiconductor material decreases with temperature, which means that more photons will have enough energy to generate electron-hole pairs.
• Pmp: The Pmp of a solar cell decreases with increasing temperature. This is because both the Voc and Isc decrease with increasing temperature.

Conclusion

Temperature has a negative impact on the efficiency and performance of photovoltaic cells. Solar cell manufacturers typically specify the temperature coefficient of their cells, so that installers can account for the expected efficiency loss when designing a solar system.

How to minimize the temperature effect on solar panel efficiency

There are a few things that can be done to minimize the temperature effect on solar panel efficiency:

• Install solar panels in a cool, shaded location. This will help to keep the panels cooler and reduce the efficiency loss.
• Use solar panels with a low temperature coefficient. This will minimize the efficiency loss for every degree Celsius increase in temperature.
• Use solar panels with a high efficiency rating. High-efficiency solar panels are less affected by temperature changes.
• Install solar panels on a tilt mount. This will help to keep the panels cooler and reduce the efficiency loss.
• Use a solar panel cleaning service. This will help to remove dirt and dust from the panels, which can reduce the efficiency loss.

Dr Murtadha Shukur thank you for your contribution to the discussion

Murtadha Shukur -- Your explanation of the decrease of Voc is incomplete: Note that even if the band gap energy of the semiconductor material were constant (i.e., independent of temperature), Voc would still decrease for increasing temperature. This is due to the thermally driven minority currents across the p–n junction: At higher temperatures, the leakage current increases (due to increased thermal generation of electron–hole pairs), so a lower voltage is sufficient to re-inject the full photocurrent into the base. (For details have a look at the above-mentioned PVCDROM page.)

Dr Jan Martin Wagner thank you for your contribution to the discussion

Photovoltaic modules are tested at a temperature of 25 degrees C (STC) – about 77 degrees F., and depending on their installed location, heat can reduce output efficiency by 10-25%. As the temperature of the solar panel increases, its output current increases exponentially, while the voltage output is reduced linearly. Current is the rate at which electricity flows through the system. Temperature affects solar panel voltage and current. As temperature increases, it reduces the amount of energy a panel produces. This is due to an increase in resistance high temperatures slow the speed of the electrical current. The Orientation, Inclination, Latitude of the place and Climatic conditions. The installation of the photovoltaic modules must take into account some factors to take full advantage of solar radiation: the orientation, the inclination, the latitude of the place, the climatic conditions. Thus for every 1oC temperature change above 25oC (hotter), the pv panel temporarily loses 0.25% of its voltage. But equally, for every 1oC below 25oC (colder), the pv panel's voltage increases by 0.25%. That is in hot weather, a lower VOC and therefore lower VMP, and in cold weather, a higher VOC and higher VMP. As the temperature of a PV panel increases above 25°C (77°F), its efficiency tends to decrease due to the temperature coefficient. The coefficient measures how much the output power decreases for every degree Celsius above a reference temperature (usually 25°C). Working in an environment that is too hot can make workers lethargic and unfocused. Heat stress can cause the body to lose electrolytes and water faster, causing low mental performance and decreased motor skills. The open circuit voltage of a PV module varies with cell temperature. As the temperature increases, due to environmental changes or heat generated by internal power dissipation during energy production, the open circuit voltage (Voc) decreases. This in turn reduces the power output.The increasing temperature causes a narrowing of the forbidden gap and a shift of the Fermi energy level toward the centre of the forbidden gap. Both these effects lead to a reduction of the potential barrier in the band diagram of the illuminated PN junction, and thus to a decrease of the photovoltaic voltage. As the temperature rises, the output voltage of a solar panel decreases, leading to reduced power generation. For every degree Celsius above 25°C (77°F), a solar panel's efficiency typically declines by 0.3% to 0.5%.

Rk Naresh -- "As the temperature of the solar panel increases, its output current increases exponentially, ...": Pardon me, but why should this be so?

As the temperature of the solar panel increases, its output current increases exponentially why? This is because there is a negative relationship between temperature with power and voltage respectively. An increase in current is evident with an increase in solar insolation, but the open circuit voltage is severely affected and this contributes to the module degradation. As the temperature rises, the output voltage of a solar panel decreases, leading to reduced power generation. For every degree Celsius above 25°C (77°F), a solar panel's efficiency typically declines by 0.3% to 0.5%. Temperature affects all electronics, and solar panels are no exception. As the temperature rises, the panels generate less voltage and become less efficient in producing electricity. This difference in charge allows electricity to flow. Current is the rate at which electricity flows through the system. Temperature affects solar panel voltage and current. As temperature increases, it reduces the amount of energy a panel produces. You can either wire multiple panels in series to increase voltage, with current (amps) remaining the same as any one panel, or wire the panels in parallel to increase current, with the voltage output remaining the same as any one panel.As the temperature increases the electrons become more energetic and so the relative barrier is lower so less gate-source voltage is required. Thus the threshold voltage is lower. Because the electrons (and so is the lattice) are more energetic there are more collisions that impede charge flow. In regard to the temperature, when all parameters are constant, the higher the temperature, the lower the voltage. This is considered a power loss. On the other hand, if the temperature decreases with respect to the original conditions, the PV output shows an increase in voltage and power. At the peak of the cycle, about 0.1% more solar energy reaches the Earth, which can increase global average temperatures by 0.05-0.1℃. This is small, but it can be detected in the climate record.

Pardon me, but I doubt the exponential increase of the current (for increasing temperature and constant insolation). Could you please explain just this?