ASTM E1038-10(2015)

4.1 In many geographic areas, there is concern about the effect of falling hail upon photovoltaic modules. This test method may be used to determine the ability of photovoltaic modules to withstand the impact forces of hailstones. In this test method, the ability of a photovoltaic module to withstand hail impact is related to its tested ability to withstand impact from ice balls. The effects of impact may be either physical or electrical degradation of the module.

4.2 This test method describes a standard procedure for mounting the test specimen, conducting the impact test, and reporting the effects.

4.3 Data generated using this test method may be used for the following: (1) to evaluate impact resistance of a module, (4.3.1 This test method requires analysis of visual effects, as well as electrical measurements. Visual effects are generally more sensitive than the electrical measurements; therefore, the absolute values for voltage and current are not critical, but repeatable conditions for before and after tests are required for determining electrical changes.

4.3.2 A range of observable effects may be produced by impacting various types of photovoltaic modules. Physical effects on modules may vary from no effect to penetration by the ice ball. Some physical changes in the module may be visible when there is no apparent electrical degradation of the module.

4.3.3 Electrical changes may vary from no effect to no output. All effects of the impacts must be described in the report so that an estimate of their significance can be made.

4.4 This test method does not specify the size or velocity of ice balls or maximum number of impacts to be used in making the test. These determinations will be based on frequency and severity of expected hail occurrences and the intent of the testing.

4.5 The hail impact resistance of modules may change as the materials are exposed to various environmental factors. This test method may be used to evaluate degradation by comparison of hail impact resistance data measured before and after exposure to other such environmental factors.

1.1 This test method provides a procedure for determining the ability of photovoltaic modules to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones.

1.2 This test method defines test specimens and methods for mounting specimens, specifies impact locations on each test specimen, provides an equation for determining the velocity of any size ice ball, provides a method for impacting the test specimens with ice balls, provides a method for determining changes in electrical performance, and specifies parameters that must be recorded and reported.

1.3 This test method does not establish pass or fail levels. The determination of acceptable or unacceptable levels of ice ball impact resistance is beyond the scope of this test method.

1.4 The size of the ice ball to be used in conducting this test is not specified. This test method can be used with various sizes of ice balls.

1.5 This test method may be applied to concentrator and nonconcentrator modules.

1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.7 This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific precautionary statements, refer to 5.1, Section 6, Note 8, and Note 9.