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 SweModule

Here are the PSI Ratings for modules from SweModule, 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
1	SweModule	265 x	Polycrystalline	265	8.14*	81
2	SweModule	260 x	Polycrystalline	260	7.97*	74
3	SweModule	255 x	Polycrystalline	255	7.89*	70
4	SweModule	250 x	Polycrystalline	250	7.72*	61
5	SweModule	245 x	Polycrystalline	245	7.67*	58
6	SweModule	240 x	Polycrystalline	240	7.52*	49
7	SweModule	235 x	Polycrystalline	235	7.36*	39
8	SweModule	230 x	Polycrystalline	230	7.10*	26
9	SweModule	225 x	Polycrystalline	225	6.94*	19
10	SweModule	220 x	Polycrystalline	220	6.84*	16

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* 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.