SPV Modules performance will be better under low ambient temperatures and high solar irradiance. Now, the STC conditions are for the reference purpose only. The best conditions for the PV power generation can be at many specific sites in many countries. In Europe Spain has best intensities and moderate temperatures. As per my understanding the best conditions suitable to Solar PV are seen in Ladak District, J & K State, India. Here the intensity of solar irradiance is the highest in the world due to refection's from Ice covered Himalayan mountains and temperatures are very low as low as -30 Degree Celsius. The intensity will be above 1030W/ sq. meter.

For information please.

O. S. sastry

The performance-related exactly to the specifications of the PV modules would never occur due to mismatch (a difference between modules).

However, the best performance would be in cloudless sky situations, avoiding shading. The temperature of 25 degrees would be a good option, but if it were a little bigger, the influence on performance is small.

SPV Modules performance will be better under low ambient temperatures and high solar irradiance. Now, the STC conditions are for the reference purpose only. The best conditions for the PV power generation can be at many specific sites in many countries. In Europe Spain has best intensities and moderate temperatures. As per my understanding the best conditions suitable to Solar PV are seen in Ladak District, J & K State, India. Here the intensity of solar irradiance is the highest in the world due to refection's from Ice covered Himalayan mountains and temperatures are very low as low as -30 Degree Celsius. The intensity will be above 1030W/ sq. meter.

For information please.

O. S. sastry

The conditions are T=25 degrees

absolute pressure of 101.325 kPa

and solar irradiance is Ir=1000w/m2(approx)*

*Average annual solar radiation arriving at the top of the Earth's atmosphere is roughly 1361 W/m2. The Sun's rays are attenuated as they pass through the atmosphere, leaving maximum normal surface irradiance at approximately 1000 W /m2 at sea level on a clear day.

The closer to the equator the higher the available irradiance. Australia, Mexico, central America, northern Chile, Saharan countries, South Africa, Namibia, the Arabian peninsula and the US Southwest seem the best places to build photovoltaic or solar thermal plants

Dear All,

First of all we are not discussing the Solar thermal power generation. We are discussing only Solar Photovoltaic power generation from PV power plants. The countries along the equator receive good annual solar irradiance, no doughty ,but the ambient temperatures are also very high, with high ambient temperature and high irradiance the cell temperature will be very high, due to which the open circuit voltage, and maximum power voltages decrease , effectively increasing the power losses from the PV modules. If there are any low temperature sites in these countries definitely there is a possibility of higher power generation.

Further, the power from crystalline silicon PV modules decrease approximately by 0.45%/ Degree Centigrade. If the cell temperature is lower than 25 degrees the generated power will be higher than STC, provided the intensity remains the same. Kindly, understand that ambient temperatures lower than 25 degree, increase the voltage and if higher/ sufficient intensity is available power generated can be higher than STC conditions. As already explained STC conditions are only reference purpose.

In Ladak region of India, not only the temperature is low, but the intensity is very high due to reflections from ice covered mountains. it is precisely for this reason this site is the most suitable and perhaps the highest PV power generating site in the world. However, the major problem is building the transmission lines/ power grid. At one time Government of India was having a mega plan on this.

Now, wind has no direct effect, but effect the module temperature and hence either increase or decrease the power output from the modules.

The atmosphere pressure may slightly influence or modify the solar spectrum. The effect of the spectrum will be on the type of technologies used. One of the STC condition is the AM1.5 Global spectrum. At present IEC 60904-4 provides the reference spectrum which is one of the reference STC condition.

I hope this explains the question in detail.

Regards

O. S. sastry

Thank you sir for your answer

The region with the best solar resource in the world is known to be the Atacama plateau in the Andes.

Thank you Chris Gueymad

Dear dr. Chris Gueymard,

Can you kindly provide more details on Irradiance level, Temperature, quality of Spectrum, number of Sunny days in year, etc. for the Atacama plateau of Andes.

Thanks

There is abundant literature on this, but I do not have specific measurements myself.

https://www.eupvsec-proceedings.com/proceedings?paper=35675

https://journals.ametsoc.org/doi/10.1175/BAMS-D-13-00175.1

https://www.researchgate.net/publication/296689488_The_Solar_Spectrum_in_the_Atacama_Desert

https://www.researchgate.net/publication/331391598_PV_Power_Production_Estimation_by_Using_Radiometric_and_Meteorological_Data

https://www.researchgate.net/publication/320002605_Sunbelt_Spectra_comparison_with_Standard_ASTM_G173_the_Chilean_case

https://www.researchgate.net/publication/325132338_Standard_or_local_solar_spectrum_Implications_for_solar_technologies_studies_in_the_Atacama_desert

https://www.researchgate.net/publication/321027776_Daily_global_solar_radiation_estimation_in_desert_areas_using_daily_extreme_temperatures_and_extraterrestrial_radiation

O. S. Sastry Interesting fact. But what about the cloud cover? How much contribution does the diffused radiation have on total radiation intensity? If the actual direct component is masked by the cloud cover, the amount of reflected radiation from the snow may not compensate the amount of direct radiation lost through the cloudy skies. As per my understanding, the Himalayan regions of Nepal and parts of India have fast changing sky conditions with clouds building frequently, which may not be as useful as you have mentioned.