ASTM E1038-10(2019)

Standard Test Method for Determining Resistance of Photovoltaic Modules to Hail by Impact with Propelled Ice Balls

SIGNIFICANCE AND USE
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.  
4.2.1 The procedures for mounting the test specimen are provided to assure that modules are tested in a configuration that relates to their use in a photovoltaic array.  
4.2.2 Six or more impact locations are chosen to represent vulnerable sites on modules and general locations are listed in Table 1. Only a single impact is specified at each of the impact locations.  
4.2.3 Resultant speed is used to simulate the speed that may be reached by hail accompanied by wind. The resultant speed used in this test method is determined by vector addition of horizontal wind velocity plus vertical ice ball terminal velocity.  
4.2.4 Ice balls are used in this test method to simulate hailstones. Hailstones are variable in properties such as shape, density, and frangibility (for fracture characteristics, see Ref (10) in Practice E822). These properties affect factors such as the duration and magnitude of the impulsive force acting on the module and the area over which the impulse is distributed. Ice balls (with a density, frangibility, and terminal velocity near the range of hailstones) are the nearest hailstone approximation known at this time. Ice balls generally are harder and denser than hailstones; therefore, an ice ball simulates the worst case hailstone. Perhaps the major difference between ice balls and hailstones is that hailstones are more variable than ice balls....
SCOPE
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, health, and environmental 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.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 31-Mar-2019
• ICS: 27.160 - Solar energy engineering
• Technical Committee: E44 - Solar, Geothermal and Other Alternative Energy Sources
• Drafting Committee: E44.09 - Photovoltaic Electric Power Conversion

Relations

• Replaces: ASTM E1038-10(2015) - Standard Test Method for Determining Resistance of Photovoltaic Modules to Hail by Impact with Propelled Ice Balls
• Effective Date: 01-Apr-2019
• Refers: ASTM E1036-15(2019) - Standard Test Methods for Electrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays Using Reference Cells
• Effective Date: 01-Apr-2019
• Refers: ASTM E1462-12(2018) - Standard Test Methods for Insulation Integrity and Ground Path Continuity of Photovoltaic Modules
• Effective Date: 01-Feb-2018
• Refers: ASTM E1036-15 - Standard Test Methods for Electrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays Using Reference Cells
• Effective Date: 01-Feb-2015
• Refers: ASTM E772-13 - Standard Terminology of Solar Energy Conversion
• Effective Date: 01-Sep-2013
• Refers: ASTM E1036-12 - Standard Test Methods for Electrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays Using Reference Cells
• Effective Date: 01-Dec-2012
• Refers: ASTM E1462-12 - Standard Test Methods for Insulation Integrity and Ground Path Continuity of Photovoltaic Modules
• Effective Date: 01-Mar-2012
• Refers: ASTM E772-11 - Standard Terminology of Solar Energy Conversion
• Effective Date: 01-Sep-2011
• Refers: ASTM E822-92(2009) - Standard Practice for Determining Resistance of Solar Collector Covers to Hail by Impact With Propelled Ice Balls
• Effective Date: 01-Apr-2009
• Refers: ASTM E1036-08 - Standard Test Methods for Electrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays Using Reference Cells
• Effective Date: 01-Nov-2008
• Refers: ASTM E1036-02(2007) - Standard Test Methods for Electrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays Using Reference Cells
• Effective Date: 01-Nov-2007
• Refers: ASTM E1462-00(2006) - Standard Test Methods for Insulation Integrity and Ground Path Continuity of Photovoltaic Modules
• Effective Date: 01-Mar-2006
• Refers: ASTM E772-05 - Standard Terminology Relating to Solar Energy Conversion
• Effective Date: 01-Apr-2005
• Refers: ASTM E1036-02 - Standard Test Methods for Electrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays Using Reference Cells
• Effective Date: 10-Oct-2002
• Refers: ASTM E1462-00 - Standard Test Methods for Insulation Integrity and Ground Path Continuity of Photovoltaic Modules
• Effective Date: 10-Oct-2000

Overview

ASTM E1038-10(2019): Standard Test Method for Determining Resistance of Photovoltaic Modules to Hail by Impact with Propelled Ice Balls provides a standardized procedure for assessing the durability of photovoltaic (PV) modules against hail impact. As hailstorms are a significant environmental threat in many regions, this test method plays a crucial role in determining the ability of both concentrator and nonconcentrator PV modules to withstand hailstone impacts, simulated by propelled ice balls. The results inform manufacturers, installers, and stakeholders regarding the hail resistance of PV modules, assisting in product development, selection, and site suitability assessments in hail-prone areas.

Key Topics

• Test Specimen Mounting: Ensures modules are mounted for testing in a configuration representative of their actual installed condition.
• Ice Ball Simulation: Uses ice balls with density, frangibility, and terminal velocity approximating natural hailstones, albeit more consistent and typically harder to simulate a worst-case impact scenario.
• Impact Locations: Specifies a minimum of six impact sites representative of vulnerable points on the module, including cell centers, cell edges, mounting supports, and electrical terminals.
• Propelled Ice Ball Velocity: Incorporates the effect of wind by calculating resultant speed through vector addition of wind velocity and vertical fall speed, closely mirroring real-world hail events.
• Physical and Electrical Assessment: Requires both visual inspection and electrical performance testing (e.g., open-circuit voltage, short-circuit current), before and after impacts, to identify physical damage and changes in power output.
• Reporting Requirements: Details the necessary information for comprehensive documentation, including module identification, test conditions, impact observations, electrical measurements, and any deviations from the standard procedure.
• Versatility and Limitations: The standard does not specify pass/fail criteria or a specific ice ball size, allowing use with various module types and regional hail data. It may be used for comparative evaluation or to assess degradation after environmental exposure.

Applications

• Product Development: Enables PV manufacturers to evaluate and improve the hail resistance of new module designs suited for installation in hail-prone regions.
• Quality Assurance: Provides a repeatable method for verifying module durability as part of routine quality control or type certification.
• Comparative Assessment: Facilitates side-by-side comparison of different modules’ resistance to hail impact, supporting procurement decisions.
• Site Assessment and Risk Management: Assists engineers and project planners in selecting appropriately robust modules for solar installations exposed to frequent or severe hailstorms.
• Failure Analysis: Used for post-damage forensic analysis to differentiate between hail-related failures and other root causes in the field.
• Research and Standards Compliance: Supports research studies and compliance verification with international requirements for PV module durability.

Related Standards

When implementing or referencing ASTM E1038-10(2019), consider these associated standards for broader context and technical alignment:

• ASTM E772: Terminology of Solar Energy Conversion
• ASTM E822: Practice for Determining Resistance of Solar Collector Covers to Hail by Impact with Propelled Ice Balls
• ASTM E1036: Test Methods for Electrical Performance of Nonconcentrator Terrestrial Photovoltaic Modules and Arrays Using Reference Cells
• ASTM E1462: Test Methods for Insulation Integrity and Ground Path Continuity of Photovoltaic Modules

These standards collectively facilitate a comprehensive approach to testing, terminology, and assessment of solar module performance and durability in the face of environmental hazards such as hail.

Keywords: ASTM E1038, photovoltaic module hail resistance, ice ball impact, solar panel durability, PV module testing, hail impact testing, photovoltaic module standards, solar energy, quality assurance, environmental durability.

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: E1038 − 10 (Reapproved 2019)
Standard Test Method for
Determining Resistance of Photovoltaic Modules to Hail by
Impact with Propelled Ice Balls
This standard is issued under the fixed designation E1038; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee.
1.1 This test method provides a procedure for determining
the ability of photovoltaic modules to withstand impact forces
2. Referenced Documents
of falling hail. Propelled ice balls are used to simulate falling
2.1 ASTM Standards:
hailstones.
E772Terminology of Solar Energy Conversion
1.2 Thistestmethoddefinestestspecimensandmethodsfor
E822PracticeforDeterminingResistanceofSolarCollector
mounting specimens, specifies impact locations on each test
Covers to Hail by Impact With Propelled Ice Balls
specimen,providesanequationfordeterminingthevelocityof
E1036Test Methods for Electrical Performance of Noncon-
any size ice ball, provides a method for impacting the test
centrator Terrestrial Photovoltaic Modules and Arrays
specimens with ice balls, provides a method for determining
Using Reference Cells
changes in electrical performance, and specifies parameters
E1462Test Methods for Insulation Integrity and Ground
that must be recorded and reported.
Path Continuity of Photovoltaic Modules
1.3 This test method does not establish pass or fail levels.
3. Terminology
The determination of acceptable or unacceptable levels of ice
ball impact resistance is beyond the scope of this test method.
3.1 Definitions—For definitions of terms used in this test
method, see Terminology E772.
1.4 Thesizeoftheiceballtobeusedinconductingthistest
3.2 Symbols—The following symbols are used in this test
isnotspecified.Thistestmethodcanbeusedwithvarioussizes
method.
of ice balls.
1.5 This test method may be applied to concentrator and
m = ice ball mass, g.
nonconcentrator modules.
d = ice ball diameter, mm.
r = ice ball radius, mm.
1.6 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
3.2.1 Speed:
standard.
−1
V = ice ball terminal, m s .
t
1.7 This standard does not purport to address all of the
−1
V = wind, m s .
w
safety problems, if any, associated with its use. It is the
−1
V = ice ball resultant, m s .
r
responsibility of the user of this standard to establish appro-
priate safety, health, and environmental practices and deter-
4. Significance and Use
mine the applicability of regulatory limitations prior to use.
4.1 In many geographic areas, there is concern about the
For specific precautionary statements, refer to 5.1, Section 6,
effect of falling hail upon photovoltaic modules. This test
Note 8, and Note 9.
method may be used to determine the ability of photovoltaic
1.8 This international standard was developed in accor-
modules to withstand the impact forces of hailstones. In this
dance with internationally recognized principles on standard-
test method, the ability of a photovoltaic module to withstand
ization established in the Decision on Principles for the
hail impact is related to its tested ability to withstand impact
Development of International Standards, Guides and Recom-
from ice balls. The effects of impact may be either physical or
electrical degradation of the module.
This test method is under the jurisdiction of ASTM Committee E44 on Solar,
GeothermalandOtherAlternativeEnergySourcesandisthedirectresponsibilityof
Subcommittee E44.09 on Photovoltaic Electric Power Conversion. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved April 1, 2019. Published April 2019. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1985. Last previous edition approved in 2015 as E1038–10 (2015). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/E1038-10R19. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1038 − 10 (2019)
4.2 This test method describes a standard procedure for repeatable conditions for before and after tests are required for
mounting the test specimen, conducting the impact test, and determining electrical changes.
reporting the effects. 4.3.2 A range of observable effects may be produced by
4.2.1 The procedures for mounting the test specimen are impacting various types of photovoltaic modules. Physical
provided to assure that modules are tested in a configuration effects on modules may vary from no effect to penetration by
that relates to their use in a photovoltaic array. the ice ball. Some physical changes in the module may be
4.2.2 Six or more impact locations are chosen to represent visible when there is no apparent electrical degradation of the
vulnerable sites on modules and general locations are listed in module.
Table 1. Only a single impact is specified at each of the impact 4.3.3 Electrical changes may vary from no effect to no
locations. output. All effects of the impacts must be described in the
4.2.3 Resultantspeedisusedtosimulatethespeedthatmay report so that an estimate of their significance can be made.
be reached by hail accompanied by wind. The resultant speed
4.4 This test method does not specify the size or velocity of
used in this test method is determined by vector addition of
ice balls or maximum number of impacts to be used in making
horizontalwindvelocityplusverticaliceballterminalvelocity.
the test. These determinations will be based on frequency and
4.2.4 Ice balls are used in this test method to simulate
severity of expected hail occurrences and the intent of the
hailstones. Hailstones are variable in properties such as shape,
testing.
density, and frangibility (for fracture characteristics, see Ref
4.4.1 If the testing is being performed to evaluate impact
(10) in Practice E822). These properties affect factors such as
resistance of a single module, or several modules, it may be
thedurationandmagnitudeoftheimpulsiveforceactingonthe
desirable to repeat the test using several sizes and velocities of
module and the area over which the impulse is distributed. Ice
ice balls. In this manner, the different effects of various sizes
balls(withadensity,frangibility,andterminalvelocitynearthe
and velocities of ice balls may be determined. However, no
range of hailstones) are the nearest hailstone approximation
point shall be impacted more than once (see 7.10).
known at this time. Ice balls generally are harder and denser
4.4.2 The size and frequency of hail varies significantly
than hailstones; therefore, an ice ball simulates the worst case
among various geographic areas. If testing is being performed
hailstone. Perhaps the major difference between ice balls and
to evaluate modules intended for use in a specific geographic
hailstonesisthathailstonesaremorevariablethaniceballs.Ice
area, the ice ball size should correspond to the level of hail
balls can be uniformly and repeatedly manufactured to assure
impact resistance required for that area. Information on hail
a projectile with known properties.
size and frequency can be found in Appendix X1 of Practice
4.2.5 Ice balls are directed normal to the surface of a test
E822 and footnotes 3 and 4 of this test method, or may be
specimen,whichtransfersthegreatestkineticenergytothetest
available from local historical weather records.
specimen, unlike a non-normal impact at a glancing angle.
4.4.3 When testing modules that are designed to be in a
4.3 Data generated using this test method may be used for stowedpositionduringhailstorms,additionalimpactlocations
the following: (1) to evaluate impact resistance of a module, should be chosen accordingly.
(2) to compare the impact resistance of several modules, (3)to
4.5 The hail impact resistance of modules may change as
provide a common basis for selection of modules for use in
the materials are exposed to various environmental factors.
various geographic areas, or (4) to evaluate changes in impact
This test method may be used to evaluate degradation by
resistance of modules due to other environmental factors, such
comparisonofhailimpactresistancedatameasuredbeforeand
as weathering.
after exposure to other such environmental factors.
4.3.1 This test method requires analysis of visual effects, as
well as electrical measurements. Visual effects are generally
5. Apparatus
more sensitive than the electrical measurements; therefore, the
5.1 Launcher,capableofpropellingaselecte
...