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 Day4 Energy

Here are the PSI Ratings for modules from Day4 Energy, 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
1Day4 EnergyDay4 60MC-I 250Polycrystalline2507.61*55
2Day4 EnergyDay448MC 190Polycrystalline1907.50*48
3Day4 EnergyDay4 60MC-I 245Polycrystalline2457.46*45
4Day4 EnergyDay4 60MC-I 240Polycrystalline2407.32*37
5Day4 EnergyDay448MC 185Polycrystalline1857.31*36
6Day4 EnergyDay4 60MC-I 235Polycrystalline2357.12*27
7Day4 EnergyDay448MC 180Polycrystalline1807.11*26
8Day4 EnergyDay4 60MC-I 230Polycrystalline2306.98*20
9Day4 EnergyDay448MC 175Polycrystalline1756.91*18
10Day4 EnergyDay4 60MC-I 225Polycrystalline2256.81*15
11Day4 EnergyDay448MC 170Polycrystalline1706.71*12
12Day4 EnergyDay4 60MC-I 220Polycrystalline2206.68*11
13Day4 EnergyDay4 60MC-I 215Polycrystalline2156.55*8
14Day4 EnergyDay448MC 165Polycrystalline1656.51*8
15Day4 EnergyDay4 60MC-I 210Polycrystalline2106.39*6
16Day4 EnergyDay448MC 160Polycrystalline1606.28*5
17Day4 EnergyDay4 60MC-I 205Polycrystalline2056.22*4
18Day4 EnergyDay448MC 155Polycrystalline1556.11*4

* 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.