PV NRT: A Correlation of Photovoltaic System Performance and Solar Irradiance

Subtitle 1– Introducing PV NRT

In the solar power industry, PV NRT (Photovoltaic Non-Reference Temperature) is a metric of performance that measures the real-world performance of photovoltaic (PV) systems when compared to standardized test conditions. NRT is specifically used to compare the operating efficiencies of different PV systems under environmental conditions. Additionally, it allows for an indication of expected performance of a given PV system across a variety of locations and climates.

Subtitle 2 – What is PV NRT?

PV NRT is a measurement of how well a PV system converts sunlight into electrical energy. More specifically, PV NRT is the ratio between the power output of a PV system under field conditions, and the same system’s performance under the ideal reference conditions of a laboratory test.

The reference conditions for a laboratory test include the ability to maintain an accurate and uniform ambient temperature, and a calibrated solar simulator. These conditions are different than most outdoor PV system installations, as the ambient air temperature and sunlight intensity varies widely depending on time of day and season. This is why the laboratory testing conditions are not seen as representative of real-world environments, and these conditions are not seen as representative of PV system performance.

Subtitle 3 – How Is PV NRT Calculated?

PV NRT is calculated by comparing the actual power output of a PV system under the varying field conditions, relative to the ideal power output under the through the standardized testing conditions mentioned above. This value is then expressed as a percentage, with a higher value indicating better performance.

To illustrate this, let’s assume the ideal power output of a PV system under laboratory conditions is a 100-watt panel, and the actual power output under a field test is rated at 85-watts. The PV NRT value for this system would be 85%.

By using PV NRT in your evaluations, you can account for any variances in irradiance due to environmental conditions and quickly understand how your PV system is performing and where it stands in reference to the performance tests.

In conclusion, PV NRT is an important metric for the solar industry, allowing for the easy comparison of PV performance under varying environmental conditions. With the help of this correlation of photovoltaic system performance and solar irradiance, you can increase the efficiency and accuracy of your evaluations, helping you to make better informed decisions.