ASTM E927-91(1997)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: E 927 – 91 (Reapproved 1997)
Standard Specification for
Solar Simulation for Terrestrial Photovoltaic Testing
This standard is issued under the fixed designation E 927; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
1. Scope E 1328 Terminology Relating to Photovoltaic Solar Energy
Conversion
1.1 This specification describes solar simulation to be used
for indoor testing of terrestrial flat plate (nonconcentrating)
3. Terminology
photovoltaic devices in conjunction with a spectrally matched
3.1 Definitions— Definitions of terms used in this specifi-
reference cell. Solar simulators are used to supply irradiance to
cation may be found in Terminology E 772 and Terminology
photovoltaic devices during a controlled indoor test. The
E 1328.
output of a solar cell is a strong function of the wavelength of
3.2 Definitions of Terms Specific to This Standard:
incident irradiance. Hence, the measured efficiency of a cell
3.2.1 field of view—the maximum angle between any two
can vary as the spectral content of the incident irradiance
incident irradiance rays from the simulator at an arbitrary point
changes. To reduce such measurement errors, the light source
in the test plane.
for the solar simulator is limited to those which offer an
3.2.2 measurement period—the period of time required to
acceptable match to the solar spectrum, as defined in this
take all the data using simulated sunlight for a particular test.
specification. Specifications for simulators matched to either a
3.2.3 nonuniformity of total irradiance (in percent):
direct spectrum (as defined in Standard E 891) or a global
Maximum Irradiance 2 Minimum Irradiance
spectrum (as defined in Standard E 892) are included in this
6 100
S D
Maximum Irradiance 1 Minimum Irradiance
specification. This specification covers both pulsed and steady-
state simulators.
where the maximum and minimum irradiances are in the test
1.2 The following precautionary caveat pertains only to the
plane area.
hazards portion, Section 6, of this specification. This standard
3.2.4 pulsed simulator—simulator whose irradiance output
does not purport to address all of the safety problems, if any,
at the test plane area is in a single short duration pulse of 100
associated with its use. It is the responsibility of the user of this
ms or less.
standard to establish appropriate safety and health practices
3.2.5 solar spectrum—the spectral distribution of typical
and determine the applicability of regulatory limitations prior
terrestrial sunlight at air mass 1.5 as defined in Standards E 891
to use.
and E 892 (see Fig. 1).
3.2.6 steady-state simulator—simulator whose irradiance
2. Referenced Documents
output at the test plane area is continuous for periods of a
2.1 ASTM Standards:
second or greater.
E 491 Practice for Solar Simulation for Thermal Balance
3.2.7 temporal instability of irradiance (in percent):
Testing of Spacecraft
Maximum Irradiance 2 Minimum Irradiance
E 772 Terminology Relating to Solar Energy Conversion
6 100
S D
Maximum Irradiance 1 Minimum Irradiance
E 891 Tables for Terrestrial Direct Normal Solar Spectral
3 where the maximum and minimum irradiances are measured
Irradiance for Air Mass 1.5
at one location in the test plane with the spread generated by
E 892 Tables for Terrestrial Solar Spectral Irradiance at Air
the irradiance varying with time over a period equal to the
Mass 1.5 for a 37° Tilted Surface
measurement period.
3.2.8 test plane area, A—the area of the plane intended to
1 contain the device under test and the irradiance monitor.
This specification is under the jurisdiction of ASTM Committee E-44 on Solar,
Geothermal, and Other Alternative Energy Sources and is the direct responsibility of
4. Components
Subcommittee E44.09 on Photovoltaic Electric Power Systems.
Current edition approved Feb. 22, 1991. Published April 1991. Originally
4.1 A solar simulator usually consists of three major com-
published as E 927 – 83. Last previous edition E 927 – 85.
2 ponents: (1) a light source and an associated power supply; (2)
Annual Book of ASTM Standards, Vol 15.03.
Annual Book of ASTM Standards, Vol 12.02. any optics and filters required to modify the output beam to
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E 927
TABLE 2 Spectral Distribution of Irradiance Performance
meet the performance requirements listed in Section 5; and (3)
Requirements
the necessary controls to operate the simulator, adjust irradi-
Percent of Total Irradiance Between 0.4 and 1.1 μm of AM
ance levels, etc.
1.5 Curve
...