Principal Solar Institute

A community for development and installation professionals in the solar industry

The Principal Solar Institute Module Ratings

The Principal Solar Institute’s scientifically designed and certified combination of tests and performance standards provide an unbiased, comprehensive rating system – the PSI PV module rating. Seven essential characteristics related to initial and long-term PV module performance are combined to create the PSI Rating:

  • Actual Tested Maximum Power vs. Advertised
  • Temperature Coefficient at Maximum Power
  • Power at Low Irradiance to Power at High Irradiance Ratio
  • Normal Operating Cell Temperature (NOCT)
  • Total Area Efficiency
  • Negative Power Tolerance
  • Annual Power Reduction

These ratings allow you to make comparisons when analyzing PV modules and help you select the optimal PV module.

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PSI Ratings – PV Solar Modules from NexPower Technology

Here are the PSI Ratings for modules from NexPower Technology, calculated based on initial performance test data. If you don’t see a solar module that you are considering, contact us and we will try to add it.

Rank Manufacturer Model Type Power
(W DC)
PSI Rating Percentile
1NexPower TechnologyNT-160Thin Film1605.56*2
2NexPower TechnologyNT-155Thin Film1555.39*2
3NexPower TechnologyNT-150Thin Film1505.20*2
4NexPower TechnologyNT-145UXThin Film1455.14*2
5NexPower TechnologyNT-140UXThin Film1404.96*2
6NexPower TechnologyNH-100UX 5AThin Film1054.10*1
7NexPower TechnologyNH-100UX 4AThin Film1003.88*1
8NexPower TechnologyNH-100UX 3AThin Film953.71*1

* Modules denoted with an “*” use estimated values for one or more characteristics. Manufacturers can contact us to provide the missing data for these PV modules.

NOTE: PSI Ratings are based on publicly available data, and are subject to change as additional data and proprietary analyses become available for long-term performance.