NOCT importance in Solar panel's performance

The performance of solar panel is highly influenced from the cell temperature around the year. This is especially important  during summer and during afternoon (ie when in high temperatures), where the solar cells reach the highest temperatures.

The more the panels are heated , the more the solar energy production is lowered!! Can you picture yourself, sweating in your living room from high temperatures of 40 C and your panel to perform even lower than a standard average day?

It can happen.

The best solar panels with highest efficiency in high temperatures

You just have to look at the indicator called Noct.
Noct is an international standard measurement of the solar panel's ability to perform in high temperatures. Noct in solar panels should be as low as possible especially in high temperature regions such as the Mediterranean countries of Europe e.g. Spain, Greece,

NOCT Definition
When you look at Noct ( Nominal Operating Cell Temperature)  you are looking at a number which indicates the temperature developed in each panel in high radiation fields. Noct shows the performance of the solar panel at high temperatures, ie higher than 25 degrees Celsius.
And the truth is that a  typical solar park in Mediterranean region will operate at yearly avg temperatures higher than 25 degrees.

STC Conditions
All panels are subject to a factory  test in standard test conditions (STC). 
That is, the panels are put in simulation conditions where they are exposed to solar irradiation of 1000 watt per square meter and maintain a temperature in the cell 25 degrees Celsius and air mass 1.5.
This test in these conditions are called STCc measurements.
These conditions however dont reflect the  actual conditions!

NOCT Conditions
For more realistic conditions Noct is the one to be used.
It's not ideal, but that is better  because the measuring conditions of noct is 800 watt / m2, 20 C air temperature and an average wind speed of 1 meter / second (2.24 miles / hour) with the back side of the photovoltaic but panels open in the breeze.

The lower the Noct, the more efficient the panel is in high temperatures over time.


Just google noct to see how important criterion for the performance of the panel is.


The best panels on the market have low Noct.

How can you find out the Noct in the panel

Just look at the technical specification sheet and look for the indicator. Here are some examples:

Example 1

Example 2

Which are the panels with the BEST NOCT 

A typical noct in the market is 46-48 Celcius degree. Over 50 is ...well not good at all, and if you find close to 42 you have something really good in your hands.
In order to achieve a low noct usually the companies have a patent or special layers etc that prevent the cell to be heated in high temperatures. There is technology behind it.







So, have another look at your offer, and check the noct of the solar panels.
Of course its not the only criterion to find a good panel but is an important and easy one to find out in the technical datasheet.