CONTRACTOR REPORTSAND83 - 7028Unlimited ReleaseUC-63a

Modular Photovoltaic Array Field

Hughes Aircraft CompanyP.O. Box 9399Long Beach, California 90810-0399

Prepared by Sandia National Laboratories Albuquerque, New Mexico 87185and Livermore, California 94550 for the United States Department of Energyunder Contract DE-AC04-76DP00789

Printed September 1984

Issued by Sandia National Laboratories, operated for the United StatesDepartment of Energy by Sandia Corporation.NOTICE: This report was prepared as an account of work sponsored by anagency of the United States Government. Neither the United States Govern­ment nor any agency thereof, nor any of their employees, nor any of theircontractors, subcontractors, or their employees. makes any warranty, ex~

press or implied, or assumes any legal liability or responsibility for theaccuracy, completeness, or usefulness of any information, apparatus, prod­uct' or process discloeed, or represente that ita use would not infringeprivately owned rights. Reference herein to any specific commercial product,process, or service by trade name, trademark, manufacturer, or otherwise,does not necessarily constitute or imply ita endorsement, recommendation,or favoring by the United States Government, any agency thereof or any oftheir contractors or subcontractors. The views and opinions expressed here­in do not necessarily state or reflect those of the United States Government,any agency thereof or any of their contractors or subcontractors.

Printed in the United States of AmericaAvailable fromNational Technical Information ServiceU.S. Department of Commerce5285 Port lWyal RoadSpringfield, VA 22161

NTIS price codesPrinted copy: A06Microfiche copy: AOI

SAND83 -7028Unlimited Release

Printed March 1984

DistributionCategory UC-63a

Modular Photovoltaic Array Field

Hughes Aircraft CompanyP.O. Box 9399

Long Beach, California 90810-0399

Under Contract No. 68-3152

AbstractThis final report describes the procurement, fabrication, assembly, installation, and test of a fixedflat-panel photovoltaic (PV) array field composed of modular 10 kWp building blocks. Implemen­tation of this hardware program was in strict adherence to the designs developed under a priorSandia contract for an array field optimization and modularity study for intermediate power (20to 500 kW) size systems. The basic objective of this program is to verify the balance of systemscosts developed under the prior study contract. Each of these modular building blocks of anominal 10 kWp was installed at the Photovoltaic Test Facility of Sandia National Laboratories,Albuquerque, New Mexico. Major features of the balance of systems incorporated ± 200 Vdcbipolar circuitry, a low cost hybrid structure/foundation featuring a frameless panel and self­grounding foundation, and a power collection center for housing the modular system controls andprotection circuits. An economic analysis of the completed project showed that the objective wasrealized for achieving an installed, low-cost balance of systems for an intermediate power, flat­panel photovoltaic array field.

/.

v-vi

PAGES iii & lv ARE BLANK

MPAF FINAL REPORT

TABLE OF CONTENTS

SECTION PAGE

1.0

2.0

Introduct ion l) ••••••••••••••• .: ••

Design

1

3

Installation , .

Procurement ' .

Checkout, Test, and Evaluation ••.•.....•••••.•..••••••.

Array Wiring •••••••••••••• '.••••••••••••••••••

336

7

77

10

10101011

11

11

14141417

17

172626

Intermodule Wiring .•.•.•••••..•.•••Field Cabling and J-Boxes ..••.•.••.Power Control Module ••.•••••••••••.Power Collection Center ••••••••••••

Photovoltaics .•....•.....•..•................J-Boxes and Cabling ..••...•.•..•.••..••••..••Power Collection Center .••••••••..••.•.••••.•

Module Matching .•••..•.••.•.••..•••.•.•••..••Panel and J-Box Installation •••••••••••••••••

3.3.13.3.23.3.33.3.4

Site Preparation and Foundations •••.••••••.••Cabling, Counterpoise, and Power CollectionCenter ' .

Structural Equipment •••••.•.•••••.•••••••..••Photovoltaic Modules ••••••.••••..••••.......•Electrical Equipment •••••••.•••••••••••••••..

Structural .........•...... ~ ............•..•..Photovoltaic Array •.•.•..• _...••.•.•...•....•.Electrical .

5.15.25.3

3.13.23.3

2.12.22.3

4.14.2

4.34.44.5

5.0

3.0

4.0

Recommendations .

Economic Analysis .6.0

7.0

7.17.27.3

Electrical Hardware .Foundations .Field Installation .

27

30

313232

8.0

9.0

Conclusions .

References .

33

34

vii-viii

Preceding page blank

LIST OF ILLUSTRATIONS

Power Collection Center ••..••.........••...............

30 kW Array Field Layout .

Array Wiring and Cabling Diagram .••.•..•.••..•..•.•.•.•

Array Structures Assembly •.••••••...•••••••••.•••••••••

Phot0 voltaicPane1 Assemb 1y ••..•...•....•..•••...•.•.•.

Assembled Panel Being Moved to Structures •.•••.•••..•••

Panel Assembly to Stanchions •.•••••••••...•.•.•.••••.•.

.................... 0, •••••••••••••••••

4

5

12

15

16

18

19

20

21

PAGETITLE

•••••••••••••••• II ••••••••••••••••••Module Matching Plan

Solarlok Connector

FIGURE

2.1-1

2.2-2

3.3.4-1

4.2-1

4.3-1

4.4-1

4.4-2

4.4-3

4.5-1

TABLE

5.5-1

6.0-1

LIST OF TABLES

TITLE

Photovoltaic Array Electrical Performance

Material and Subcontract Procurement .•••.••..••••.•.•••

PAGE

24-25

28

APPENDICES

A Solar Cell Module Product Specification

B

C

General Contractor Statement of Work

Block IV Test Data

D

E

Environmental Test Reports

Hot Spot Endurance Test Report

ix-X

-Preceding page blank

ACKNOWLEDGEMENT

This procurement and installation of the Modular Photovo1taic ArrayField (MPAF) was conducted by Hughes Aircraft Company with George J. Naffserving as Program Manager and Leo A. Shi110ng as Project Engineer.The very able assistance of Mr. Sid Johnston of Sandia Laboratories isgratefully acknO\'11edged and deeply appreciat,ed. Also acknowledged anddeeply appreciated are the contributions of the following participants:

Hughes Aircraft Company

Solarex Corp.

Abbott MechanicalContractors, Inc.

N. MarshallM. Van LeeuwenD. CohenN. ChaseJ. CastleJ. Wi '11 i amsonY. HOI"ning

J. HOI~l scher

F. Abbott

xi-xii-~..-_..---

Preceding page blank

FINAL REPORT

MODULAR PHOTOVOLTAIC ARRAY FIELD

1.0 INTRODUCTIONIf the creation of a viable industrial and commercial market is to beachieved, reducing photovoltaic (PV) system costs is essential.

One approach to reduce the system costs is dE~veloping a standard arrayfield building block that either alone or in multiples satisfies asubstantial portion of the intermediate sector needs. This strategywould greatly reduce site specific design work. Also, including

innovative installation and fabrication techniques, and low coststructures and optimized field wiring designs, would signficantly

reduce overall system costs.

Under Sandia Contract No. 62-9188, the Hughes Aircraft Company hasconducted an Array Field Optimization and Modularity (AFOM) Study

(Ref. 1) to develop optimum designs of PV array fields and a modulararray field building block. Under Sandia Contract No. 68-3152, Hughesfabricated, assembled, installed, tested, and put into operation aModular Photovoltaic Array Field (MPAF) based on the modular buildingblock design of the AFOM project. This array, composed of threemodular 10 kW array field building blocks, was installed at thePhotovoltaic Test Facility at Sandia Nationa"1 Laboratories andinterfaced with the Sandia provided power conditioning system and load.

The prime objective of this program was to fabricate and install the

MPAF that will act as a test bed, allowing Sandia to evaluate thefindings of the AFOM study program, including array field

characteristics, design/component reliability, durability, and,particularly, the Balance of System (BOS) cost projections.

-1-

The array field modular building block was designed as a ~ 200 Vdc

bipolar unit with a nominal power rating of 10 kW. The building blockconsists of two 200 Vdc monopolar subarrays oriented in an east-west

row. Each building block array structure is 160 ft long andaccommodates 40 PV Panels, each panel containing four 2 ft by 4 ft PV

modules. The panels are secured at the appropriate tilt angle to afront and rear row hybrid foundation. The front row foundation is a

buried metal foot structure that acts as a buried ground counterpoiseand is an integral part of a grounding net. The rear row foundation isa concrete curb designed to withstand the priamry wind lifting forces.

Power from each building block is routed from the junction box to aPower Collection Center (PCC) via direct burial cable. The PCC

contains circuit breakers, bus bars, and Power Control Modules (PCMs)each capable of servicing two building blocks; thus, the field is

sectionalized from a control standpoint in 20 kW increments.

Procurement of hardware adhered strictly to the design developed underthe AFOM program. The selected PV module configuration was

qualification tested to ensure trouble free service over the projectedtwenty year life. To assist in the site preparation and installation,

Hughes obtained the services of a general contractor from theAlbuquerque area. The system was installed and checked out on site by

both Hughes and the general contractor. The system performed asdesigned and, following final testing, was accepted by Sandia on 25

February 1983.

When the differences between the AFOM assumptions and the MPAF lI one-of­a kind ll procurement are considered, the BOS costs compare very

favorably with those developed under the AFOM design study. The BOScosts are no longer a major concern in making photovoltaic power

affordable.

-2-

2.0 DESIGN

2.1 STRUCTURAL

The structure/foundation configuration utilized in the Sandia array isdescribed in Section 4.2.2.4 (page 4-16) of Ref. 1. A typical segmentof this assembly is depicted in Figure 2.1-1.

The structural members were brake formed from low carbon sheet steelmaterial and hot dip galvanized per the specifications of the ASTMA527. The benefits of this structural system include its excellentcorrosion resistance and its economy of fabrication. This economyresults from the efficiency of specifying wall thickness proportionalto each member1s load requirements, the ability to punch holes

economically into the flat stock prior to forming, and the low cost ofthe raw sheet material.

Fasteners joining the aluminum PV module frames to the galvanized panelframes are stainless steel to preclude potential dissimilar metalcorrosion. Because zinc is compatible with aluminum, galvaniccorrosion does not exist at the junctions of the panel and moduleframes. Other fasteners joining the structures are protected fromcorrosion by cadmium or zinc plating.

2.2 PHOTOVOLTAIC (PV) ARRAYThe basic PV constituent is the 5.2 Vdc, 66 watt, 2 ft x 4 ft solarcell module described in Hughes Procurement Specification SEP-11387(Appendix A). Forty of these modules are series connected in a foldedconfiguration (twenty modules per row) to form one string. Two stringsare connected in parallel to form a pole. Two poles (positive andnegative) form a ! 200 Vdc, nominal 10 kW building block. A buildingblock is represented by one of the three rows shown in Figure 2.2-2.To achieve the nominal 30 kW system; three of these building blockswere installed. Modules are interconnected using Amp Solarlok

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connectors. A junction box was located at the inner end (center) of

each pole for collecting PV power.

2.3 ELECTRICALThe electrical design of the modular 30 kW system incorporated thedesign features contained in Reference·1. The exception was thelightning arrestors, deemed unnecessary because of surrounding

structures.

The major electrical design attributes are incorporated to:(a) Prevent injury to personnel.(b) Prevent or minimize damage to equipment.(c) Minimize the effect of disturbance upon the uninterrupted

portion of the array field, both in extent and duration.(d) Minimize unwanted interaction with the interacting power

system.(e) Provide the requisite level of protection at minimal life

cycle energy costs.(f) Achieve modular expandability in a cost effective manner.

Choosing bipolar electrical distribution satisfied the aboveconsiderations. Bipolar distribution offers lower stress voltages tothe dielectric materials used in the system, and also ensures goodground fault protection at the lower line-to-ground potential. Usingvoltage suppression devices and snubbers minimizes any disturbance orinteraction on the lines.

Isolating the system at various points was essential to the safety ofpersonnel and equipment. The Power Collection Center (PCC) ismodularly expandable and can accommodate increases of building blockpower up to 100 kW by merely adding Power Control Modules (PCMs) into

the PCC enclosure. A PCM can handle up to 20 kW. All the electricalhardware was chosen from commercially available products complying withthe local and national electrical codes.

8

3.0 PROCUREMENT

3.1 STRUCTURAL EQUIPMENT

The structural equipment for the PV modules was procured as an opensubcontract solicitation. Shop drawings were prepared, sent to anumber of local Los Angeles and Albuquerque vendors for fixed pricequotations, and the order was placed with the lowest bidder. Because

all the structural members were made to dimensioned drawings, Hughesinspected all parts for conformance and then shipped them to the Sandia

site.

In the interest of shipping efficiency, Hughes initially planned toassembly the PV panels at the Hughes facility; however, PV modules from

the East Coast vendor and the panel structural members from the WestCoast were both shipped directly to Albuquerque. The panel assembly

task was added to the Statement of Work (see Appendix B) to beperformed by the Hughes' general subcontractor installing the array.

Details of this panel assembly are discussed in the installationSection 4.4 of this report.

To effect the installation of the system hardware, Hughes decided tosubcontract this work to a general contractor in the Albuquerque area.Solicitations to bid, along with Statements of Work (see Appendix B),were mailed to four contractors; three bids were received. The bidswere reviewed by a Hughes Source Selection Board composed ofprocurement, pricing analysis, and engineering personnel. AbbottMechanical of Albuquerque, the lowest bidder, was selected by theboard.

3.2 PHOTOVOLTAIC (PV) MODULESHughes prepared a solar cell module product specification (No. SEP11387 inclu~ed in Appendix A) for procuring the PV modules. Requestsfor quotes for these modules were sent to six PV modules manufacturers:

Arco Solar, Solec International, Solarex Inc., Solar Power Corp.,Photowatt Inc., and Motorola. Hughes evaluated the responses for

9

technical acceptability. The final selection of Solarex Inc. was based

on price, delivery, and compliance to the specification.

The specification defines the electrical performance parameters andmechanical design of the module. The specification, conforming toJPL' S Block V solar cell module design and test specification (Ref. 2),defines all the quality assurance provisions which ensure that all

requirements will be met, including acceptance and qualificationtesting.

The qualification test requirements specify five environmental tests

from the JPL Block V Specification:

o Thermal Cycleo Humidity Freeze Cycleo Mechanical Loadingo Twisted-Mounting Surfaceo Hail Impact

Solarex submitted Block V data (Letter, October 18, 1982 - see AppendixC) qualifying the module by similarity on the latter three tests above.

Full thermal cycle and humidity freeze testing were conducted on theSolarex PV modules by an independent testing laboratory, Litton/Amicon,

to the JPL Block V test specification. The modules satisfactorilypassed these tests (See Appendix D - Environmental Test Report onHughes/Sandia Photovoltaic Modules, December 2, 1982).

Additionally, these modules were subjected to a hot spot endurancetest; the modules successfully passed this test. Appendix E contains

the hot spot endurance test report submitted to Hughes by Solarex.

<

All production lot modules were subjected to acceptance testing. Eachmodule was visibly inspected for any non-conforming or damaged frontsurfaces, frames, solar cells, interconnects, solder joints, laminates,terminals, diodes, and dimensional variations.

10

Each module's electrical performance was determined by obtaining acurrent-voltage (I-V) curve of the module under a pulsed xenon solarsimulator at standard conditions. Each module was sorted into one oftwelve current groups (A through L), based on the I-V curve performancedata.

The performance distribution of the modules procured for thisinstallation is shown below:

Current (Amps) Quantity ofGroup at 5.2 Volts Modules Received

A 11.27 - 11.50 0B 11.50 - 11. 75 aC 11. 75 - 12.00 2D 12.00 - 12.25 6

E 12.25 - 12.50 19F 12.50 - 12.75 38G 12.75 - 13.00 78H 13 .00 - 13.25 133I 13.25 - 13.50 115J 13.50 - 13.75 50K 13 •75 - 14.00 31L Above 14.00 8

In addition to electrical performance testing, each module was also

subjected to a 3000 Vdc electrical isolation test and a diodeverification test. All acceptance test data were submitted to Hughesfor review and approval.

A sample of three production modules selected at random by a Hughesrepresentative was sent to Hughes Support Systems, Long Beach forinspection and performance verification. Hughes obtained I-V curvesfor each of the modules under natural sunlight conditions. The datawere corrected to standard conditions of AM 1.5, 1000 W/M2, and 250Ccell temperature. The performance of these modules agreed with

Solarex's acceptance test data within less than + 2 percent.

11

All but the above three mdoules were shipped in plywood, palletized

shipping containers directly from Solarex Inc., Rockville, Maryland toSandia National Laboratories in Albuquerque, New Mexico. The modules

were packaged fourteen to a container, stacked vertically, resting ontheir 4 ft edge, and held in place with a foam separator.

During shipment twelve of the twenty-six containers were turned ontheir sides. Because of inadequate bonding, the foam separators cameloose, and the modules were found lying against one another. Otherthan scratches to the module frames, only two modules appeared to havedamage to the back surface. One had a tear in the tedlar backing,

which was repaired, and the other had small dents. Module performancewas unaffected.

3.3 ELECTRICAL EQUIPMENT

3.3.1 Intermodule WiringFactory fabricated intermodule jumpers of insulated No. 10 AWG wirewith male Solarlok connectors were purchased directly from Amp Inc.

The Solarlok male connectors were compatible with the PV modulereceptacles.

3.3.2 Field Cabling and J-Boxes

The UL listed field cabling was procured to National Electric Code(NEC) Standards for direct burial cable. The J-boxes were outdoor NEMA

3R type fabricated by Pico Metals, Los Angeles. Terminal blocks wereinstalled in the boxes prior to shipping to Sandia.

3.3.3 Power Control Module (PCM)Two PCMs were assembled using commercial electrical components. Thecomponents were mounted on a standard 19 inch RETMA panel. the PCMs

contained the manual crowbar, the blocking diodes, and suppressiondevices. Each PCM can handle up to two 10 kW building blocks.

12

3.3.4 Power Collection Center (PCC)The PCC enclosure (see Figure 3.3.4-1) was fabricated by the Square DCompany, Los Angeles, CA. Square Dwas chosen because its equipmentconforms to the NEC codes and utility standards. The PCC enclosurecollects the power from the array at one centralized control point.The PCC incorporates a NEMA 3R outdoor enclosure and consists of theSquare D I-line breaker switch board terminating in 400 A main lugscapable of handling 2/0 through 500 MCM cable. A rack above the switchboard is used to mount PCMs. The size of the PCC enclosure satisfiesthe modularity requirement by allowing for the installation of multiple(up to five) PCMs. Each PCC enclosure is capable of handling up to teneach 10 kW building blocks. Modularity is maintained beyond tenbUilding blocks by replicating the PCC, one PCC for each additional oneto ten building blocks. The enclosure has two doors, one front and onerear, that can be locked for safety. The front door offers access tothe manual crowbars on the PCM panels and to the disconnect circuitbreakers on the switch board. The rear door opens into the compartmentwhere all input and output cables are terminated.

4.0 INSTALLATION

4.1 SITE PREPARATION AND FOUNDATIONSThe installation site had recently been cleared of asphalt, so siteclearing by Hughes was not required. Major surface unevenness wasrough smoothed with the bucket on the trenching back-hoe, and finalsmoothing was done while back-filling the foundation. The site issloped approximately 1 percent in the east-west direction andapproximately 1.5 percent in the north-south direction. The east-westslope is negligible from an array installation standpoint; the north­south slope was accommodated by adjusting foundation trench depths.

All the trenches were dug with a back-hoe after the site was surveyedand the trench and PCC Pad locations were marked. A wheel trencher wasoriginally proposed, but the back-hoe provided a smoother trench

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bottom. The trench bottom was covered with an inch of sand to aid intrench foot leveling during the front earth foot/stanchioninstallation.

Pre-assembly of two or three foundation segments along the clear trench

edge during the front foundation installation was soon found to be in­efficient due to the cumbersome handling of these assemblies and due to

the inevitable spillage of dirt into the trench during assemblyplacement. Assembling these parts in the trench proved to be moreefficient when performed by a technician seated on the clear trenchedge and bending forward to install the fasteners. After loose

assembly of a row of feet and stanchions (Figure 4.3-1), a string wasstretched along the row of stanchion tops for alignment reference. To

set lateral stanchion spacing, the small alignment angles (Figure 4.3­1) were bolted across the stanchion tops. The stanchions were then

secured in sequence using the reference string and a level to verifyalignment. The fasteners were then tightened and the trench wasmanually filled to 1/4 depth to secure the stanchion positions.

The secured front stanchions served as the locating fixtures for therear concrete curb stanchions. Rear stanchions were bolted to the

large alingment angles and placed into the concrete curb trench. Thefront ends of the large alignment angles were then bolted to the frontstanchions, and small alginment angles were bolted across the rearstanchions for lateral alignment. With the rear stanchions secured as

described, a concrete ready mix truck was driven down the array rows,and the rear concrete curb trenches were filled with concrete,completing the array foundation installation.

The pee foundation, consisting of a 4 ft x 3 ft concrete pad 4 inchesthick above grade, was simply formed and poured during the array curb

foundation filling. The front stanchion trenches were backfilled, andthe site smoothing was completed after all foundations were in place.

This task was largely accomplished with the back-hoe and finished withshovels and rakes. The site sterilization and gravel application were

accomplished after the system installation was completed.

15

4.2 CABLING, COUNTERPOISE, AND POWER COLLECTION CENTER (PCC)After completing the array structure installation, the J-boxes weremounted at the inner ends of the rows to collect the power from the PVarray. Power cables were laid in the open cable trench and run fromthe J-boxes to the PCC (Figure 4.2-1). Cables between the pole J-boxeswere pulled through the PVC conduit and connected to the respectiveterminal blocks within the J-Boxes. All connections were marked andchecked for continuity. After the checkout, the ground counterpoisecables were laid over the power cables (separated by about six inchesof earth) and secured to the PCC, the fence, and the arrays. Thetrench was filled and later the entire array field was covered withgravel.

4.3 MODULE MATCHINGDuring factory acceptance testing all modules were sorted in one-

quarter ampere module groupings. This grouping allowed for selectingmodules of closely matched performance to be installed in a given 40module circuit. The module manufacturer provided a list of the modulesidentified by grade (See Paragraph 3.2). Hughes prepared a map (Figure4.3-1) of the array, showing the location of each module grade. Eachshipping container label showed the quantity and current grade of themodules packaged inside. Also, each module was conspicuously gradelabeled; therefore, the additional time to install a matched modulearray was insignificant.

4.4 PANEL AND J-BOX INSTALLATIONThe solar panel components (PV modules, panel frames, and fasteners)

were shipped spearately for onsite assembly by the general contractor.This assembly was done on a sheet of 3/4 inch plywood laid across awork stand. The assembly process took place as follows: Four 2 ft x 4ft modles were placed face down on the plywood surface with their edges

and corners aligned with the edges and corners of the plywood sheet;the module support channels were placed along the module ends withtheir holes aligned with the mounting holes in the modules. Stainlesssteel fasteners were inserted and tightened to complete the panel

assembly. Figure 4.4-1 depicts this operation.

16

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While on the work table, the panel support legs were loosely bolted tothe panel. this assembly was then carried by two technicians to itsassigned location on an array row (Figure 4.4-2) where the lower panelchannel extensions were placed on the ground just behind the frontfoundation stanchions. The rear of the panel was then raised to allowthe lower end of the panel support legs to be bolted to the rearfoundation stanchions (Figure 4.4-3). The front of the panel rails was

then lifted and bolted to the front stanchions. A team of twoinstallers was used to accomplish these panel .installation steps.

A J-box mounting channel (Figure 4.3-1) was mounted onto each of theinner row end panel structures in the orientation and locationspecified in the figure. The panel structure was match drilled to the

holes in the mounting channel. The channels were then bolted to thepanel structure, and the J-boxes were bolted to the mounting channel,completing the J-box installation.

4.5 ARRAY WIRINGThe PV array wiring turned out to be a very quick and simple operation,

a few seconds per connection, by using the Solarlok connectors andjumper cables (See Figure 4.5-1). PV modules were daisy-chain wired byrelatively unskilled personnel. The wiring from the arrays to the J­boxes were deferred intentionally as a safety measure until allpreliminary testing and checkout were completed. Final hook-up wasperformed as the system was readied for commissioning tests.

5.0 CHECKOUT, TEST, AND EVALUATION

5.1 PHOTOVOLTAICS (PV)After all the modules had been installed, both the front and backsurfaces of each module were inspected for gross damage. As mentioned

in Section 3.2, two modules had been found to have slight shippingdamage (later repaired) that did not affect their performance.

22

23

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24

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The PV modules in a 40 module string were series, daisy-chain connectedusing the Solarlok jumper cables. The string of modules was thenconnected to the J-boxes.

An I-V curve of each 40 module string was obtained. Simultaneously,module temperature and solar intensity (at the modulels orientation of

35 0 to the horizontal) were recorded. Temperature was recorded bytaping a thermocouple to the back surface of a module, a technique that

results in a conservative estimate of power when corrected to 25 0 C;the measured temperature of the back surface of the module is somewhatcooler than the actual solar cell junctions.

Intensity was obtained from an Epply pyranometer placed adjacent to andat the same angle as the string of modules being measured. The I-Vcurve was generated on an automatic sweep load provided by Sandia.This equipment also determined and printed out short circuit current

(I sc )' open circuit voltage (Voc )' current at the maximum power point(Imp)' and voltage at the maximum power point (Vmp )'

Current readings were corrected to standard intensity with thefollowing formulae:

Where:

Isc = Recorded short circuit current

lIse = Short circuit current @1000 W/m2

Imp = Recorded maximum power current

limp = Maximum power current @ 1000 W/m2

26

~Isc = Difference between short circuit current @1000 W/m2

and recorded short circuit currentE = Recorded pyranometer intensityEI = Pyranometer intensity @1000 W/m2

Voltage readings were corrected for temperature with the followingformulae:

~V = 1.1424 v/oe (T-250e)V1

mp = Vmp + ~V

VI

OC = Voc + ~V

Where:

T = Recorded temperature~V = Voltage difference due to temperature difference between

recorded temperatures and 250eVmp = Recorded maximum power voltage

Vl

mp = Maximum power voltage at 250eVoc = Recorded open circuit voltage

VI

OC = Open circuit voltage at 250e

Each pole (both upper and lower strings connected in parallel) was alsotested in a similar manner.

Table 5.1-1 shows both the raw and corrected data. The three lettercode indicates from which string the data was obtained.

1st Letter: W= WestE = East

2nd Letter: A = 1st RowB = 2nd Rowe = 3rd Row

3rd Letter: U = Upper stringL = Lower string

P = Upper and lower strings in parallel

27

PVAR

RAY

ELEC

TRIC

AL

PERF

ORM

AN

CE

TABL

E5

.1-1

STR

ING

HAU

WAU

WAL

WAL

WAL

EAU

EAU

EAL

EAL

EBU

TIM

E(M

ST)

11

:15

11

:21

11

:24

11

:26

11

:30

11

:37

11

:39

11

:43

11

:46

12

:00

Ise

(AM

PS

)

12

.7

13

.5

13

.3

13

.3

13

.4

13

.5

13

.8

13

.4

13

.9

13

.3

Voe

(VO

LTS)

257

260

258

258

258

260

261

258

258

258

Imp

(AM

PS

)

11

.1

11

.7

11

.6

11

.6

11

.6

11

.7

12

.3

11

.9

12

.2

11

.7

Vmp

Pmp

(VO

LTS)

(WA

TTS)

203

2267

204

2414

202

2350

203

2364

203

2364

207

2442

203

2509

198

2368

198

2439

201

2372

INSO

LATI

ON

(MV

x10

0)

930

928

946

958

951

947

982

956

984

912

T (OF

)

89 88 87 86 88 83 83 84 85 90

INTE

NSI

TYCO

RREC

TIO

N

1.0

69

9

1.0

72

2

1.0

51

8

1.0

38

6

1.0

46

3

1.0

50

7

1.0

13

3

1.0

40

8

1.0

11

2

1.0

91

0

6Is

e(A

MP

S)

.88

8

.975

.69

9

.51

4

.62

0

.68

4

.18

3

.54

7

.15

5

1.2

1

,Im

p(A

MP

S)

11

.99

12

.67

12

.40

12

.11

12

.22

12

.38

12

.48

12

.45

12

.35

12

.91

b"V

t(V

OLT

S)

7.6

1

6.9

7

6.3

4

5.7

1

6.9

7

3.8

0

3.8

0

4.4

4

5.0

7

8.2

4

,Vm

p(V

OLT

S)

21

0.6

21

1.0

21

0.3

20

8.7

21

0.0

21

0.8

20

6.8

20

2.4

20

3.1

20

9.2

,Pm

p(W

ATT

S)

2525

2674

2608

2528

2566

2611

2581

2520

2509

2701

f\)

CDEB

U

EBL

EBL

WBU

,·lE

U

HBL HBL

WCU

HCU

HCL

WCL

12

:03

12

:06

12

:09

12

:16

12

:18

12

:21

12

:23

12:3

2

12

:35

12

:37

12

:40

13

.7

13

.0

13

.6

14

.1

14

.0

13

.8

13

.7

14

.3

14

.2

13

.8

13

.8

260

256

256

258

258

255

255

257

256

253

253

12

.1

11

.1

11

.7

12

.4

12

.4

11

.8

11

.9

12

.7

12

.5

12

.1

12

.0

203

203

202

202

202

201

200

202

202

195

196

2472

2279

2386

2530

2518

2384

2382

2578

2542

2372

2375

920

939

977

983

975

977

975

973

960

966

968

90 89 90 92 90 95 95 94 96 96 95

1.0

81

5

1.0

59

6

1.0

18

4

1.0

12

2

1.0

20

5

1.0

18

4

1.0

20

5

1.0

22

6

1.0

36

5

1.0

30

0

1.0

27

9

1.1

2

.775

.25

1

.172

.28

7

.254

.281

.32

3

.51

8

.414

.385

13

.22

11

.88

11

.95

12

.57

12

.69

12

.05

12

.18

13

.02

13

.02

12

.51

12

.38

8.2

4

7.6

1

8.2

4

9.5

1

8.2

5

11

.41

11

.41

10

.78

12

.05

12

.05

11

.41

21

1.2

21

0.6

21

0.2

21

1.5

21

0.2

21

2.4

21

1.4

21

2.8

21

4.0

20

7.0

20

7.4

2792

2501

2513

2659

2667

2560

2575

27

71

2786

2591

2569

PVAR

RAY

ELEC

TRIC

AL

PERF

ORM

ANCE

(CO

NT.

)

TABL

E5

.1-1

STR

ING

ECU

ECU

ECL

ECL

ECP

ECP

:rIM

E(M

ST)

12

:45

12

:48

12

:50

12

:54

1:0

0

1:0

3

Isc

(AM

PS)

14

.1

14

.2

13

.8

13

.7

27

.4

27

.7

Voc

Imp

(VO

LTS)

(AM

PS)

255

12

.5

255

12

.4

253

11

.9

254

11

.9

256

23

.8

256

24

.3

Vmp

Pmp

(VO

LTS)

(WA

TTS)

198

2498

201

2503

198

2368

198

2368

202

4839

201

4903

INSO

LATI

ON

(MV

x10

0)

968

980

963

963

942

970

T (OF

)

96 93 94 91 90 88

INTE

NSI

TYCO

RREC

TIO

N

1.0

27

9

1.01

53

1.0

332

1.0

332

1.05

63

1.02

58

6Is

c(A

MPS

)

.393

.217

.459

.455

1.5

42

.71

4

•Im

p(A

MPS

)

12

.89

1262

12

.36

12

.36

25.3

4

25

.01

6V

t(V

OLT

S)

12

.05

10

.14

10

.78

8.8

8

8.2

4

6.9

7

•Vm

p(V

OLT

S)

21

0.0

21

1.1

208.

8

20

6.9

210.

2

20

8.0

,Pm

p(W

ATT

S)

2708

2664

2580

2556

5328

5202

256

24

.319

748

22W

CPf\

)

\.0

IW

CP

WBP

WBP

EBP

EBP

EAP

EAP

WAP

WAP

*W

AP*

1:1

1

1:1

4

1:2

6

1:2

9

1:4

0

1:4

3

1:5

2

1:5

5

2:0

1

2:2

5

2:2

6

27

.2

27

.0

26

.5

25

.5

26

.0

25

.5

24

.1

23

.4

23

.4

23

.0

22

.4

256

256

256

255

254

254

255

257

258

257

24

.1

22

.9

21

.9

22

.4

22

.2

21

.2

20

.5

20

.6

20

.3

19

.8

198

203

203

202

200

197

198

198

196

194

4803

4669

4472

4544

4443

4199

4079

4103

4007

3864

942

933

920

900

913

894

844

820

816

834

778

92 91 89 94 88 89 87 87 84 82 82

1.05

63

1.06

65

1.08

15

1.1

05

6

1.08

98

1.1

13

0

1.17

89

1.21

34

1.2

19

4

1.1

93

1

1.27

89

1.5

31

1.7

94

2.1

6

2.6

9

2.3

4

2.8

8

4.:n

4.9

9

5.1

3

4.4

4

6.2

5

25

.83

25.8

9

25

.06

24

.59

24

.74

25.0

8

25

.51

25

.49

25

.73

24.7

4

26.0

5

9.5

1

8.8

8

7.6

1

10

.78

6.9

7

7.6

1

6.3

4

6.3

4

4.4

4

3.1

7

3.1

7

206.

5

20

6.9

21

0.6

213.

8

20

9.0

20

7.6

20

3.3

20

4.3

202.

4

19

9.2

19

7.2

5334

5357

5278

5257

5169

5207

SIR

S

5209

5209

4927

5136

*LA

MP

POST

SHAD

OWED

MOD

ULE

All strings and poles performed satisfactorily.

Several modules in the A row were fully or partially shadowed todemonstrate that the module shunt diode design worked effectively. Theperformance of the shadowed strings was as predicted. The diodes ofthe shadowed modules "turned on," and the string voltage was reduced bythe amount of the diode drop and the loss of the shadowed module'svoltage output.

5.2 J-BOXES AND CABLING

Continuity tests were made on the cabling during the installation ofthe cables. The array was connected in stages to the J-boxes andvoltages were measured at the terminal blocks. Voltage was not placedon the cables as they were not wired into the PCMs.

5.3 POWER COLLECTION CENTER (PCC)No formal test procedure was prepared because of the checkout'ssimplicity. The system schematic was used and methodical checkoutswere conducted. The PCMs had been checked during factory assembly.The two PCMs were mounted into the PCC and the cable connections made.

Voltage measurements were made at the input and output of the PCMs.The disconnect switches were operated, and the voltage was checked atthe main lugs. The manual crowbar on the PCMs was operated, andvoltage and current measurements made. The ground faultindicator/detector was installed and checked out.

A temporary test panel was installed in the rear of the PCC so thatmeasurements could be made in the field. The test panel wa~ used torun I-V curves during the test phase. As part of the testing, theSandia load bank was used for the initial load test. The overalltesting went very well and the system performed better than expected.

30

6.0 ECONOMIC ANALYSISFabricating, installing, and testing the 30 kW Modular PhotovoltaicArray Field (MPAF) were undertaken primarily to verify the costprojections developed during the Array Field Optimzation and Modularity(AFOM) Study. Detailed records on material, labor, installation, andtest costs were maintained. A listing of the MPAF material andsubcontract procurements is shown in Table 6.0-1. These costs aresubsequently summarized in terms of dollars per square meter of BOScosts. The 30 kW array field consists of 356 square meters ofphotovoltaic collectors.

In the original AFOM Study, a life cycle cost analysis was performed.In it the following economic factors were assumed:

Dedicated factory producingSystem operating lifetimeEffective income tax rateGeneral inflation rateEscalation rate for capital costEscalation rate of 0 &McostBase year in constant dollarsCost of capital

10 MEGAWATTS/YEAR20 YEARS

40%12%12%12%

198015%

The following burdened labor rates. including a nominal profit of 10percent, were also used:

Factory Labor

Field LaborSemi-skilledSkilledSupervisory

Material Cost Make-upShipped directly to siteProcessed at factory

31

$18.50/Hr.

$20.00/Hr.28.00/Hr.35.00/Hr.

+20%+30%

MATERIAL AND SUBCONTRACT PROCUREMENTTABLE 6.0-1

DESCRIPTION VENDOR PRICE

PV MODULES SOLAREX CORP. $316,211ROCKVILLE, MD

GE MOVS HAMILTON CO. 75LOS ANGELES, CA

BLOCKING DIODES KIERULFF 164LOS ANGELES, CA

J-BOX CORE PICO 370LOS ANGELES, CA

ARRAY WIRING &CONNECTORS AMP 2,153LARGO, FL

MISC. ELECTRICAL HARDWARE VARIOUS 334

PVC ADAPTERS/COUPLINGS/ GRAYBAR 229ELBOWS LOS ANGELES, CA

100 kW ENCLOSURE CEO 3,485LOS ANGELES, CA

CABLES GE SUPPLY 914LOS ANGELES, CA

STRUCTURES &FOUNDATIONS A &M 6,519LOS ANGELES, CA

1/4 GALVANIZED WIRE VER SALES INC 135LOS ANGELES, CA

GENERAL CONTRACTOR ABBOTT 32,897ALBUQUERQUE, NM

CIRCUIT BREAKERS CROWBAR GRAYBAR 215LOS ANGELES, CA

STRUCTURES HARDWARE LAVENDER 1,127COSTA MESA, CA

TOTAL $364,828

32

Based on these factors, the AFOM BOS costs (at price to the customer)projected for a 100 kW modularized system are shown below along with

(a) the actual BOS costs experienced in the MPAF 30 kW project; and(b) the projected BOS costs for a second MPAF system, 100 kW, if

it were to be built in 1983 based upon the fabrication andinstallation experience gained from the 30 kW MPAF.

100 kW AFOM 30 kW MPAF 100 kW MPAF$/m2 (1980$) $/m2 (1982$) $/m2 (1983$)

Electrical Hardware $ 15.55 $ 22.68 $ 19.96

Structure/Foundations 16.73 21.48 20.62Field Installation 27.27 92.41 68.60

Totals $136.57 $109.18Totals (In 1980 $) $ 59.55 $118.04 $ 89.05

The above cost categories include:

(a) Electrical Hardware: Acquisitions costs of parts, subassemblies,factory test, and transportation to site.

(b) Structures/Foundations Hardware: Acquisition costs of parts,subassemblies, attachment hardware, and transportation to site.

(c) Field Installation: Costs for site preparation, trenching,concrete, field assembly, installation and checkout of theelectrical and mechanical subsystems, and ground sterilization.

A factor of two exists between the AFOM projected costs and the 30 kWMPAF actual costs. Most of this difference stems from the 30 kW arrayhaving been a "one of a kind project" and not part of an overall 10 MWannual production base. Also, as this 30 kW array was the firstmanufactured article of the AFOM design, much greater attention was

paid to the PV modules, power conditioning, and structural subsystemsthan would have occurred if this were one of many factory fabricated,installed projects.

33

As the MPAF was only a 30 kW array consisting of several small volumeprocurements~ no price breaks could be obtained on material purchases,such as PV modules, PV jumper cables~ connectors~ field cables~ orstructural elements.

Also~ this project was essentially an "engineering" project rather thana "production/factory" project; therefore~ expensive engineeringpersonnel performed tasks~ such as quality assurance and control~ siteinstallation supervision, vendor liaison~ and electrical test andcheckout, that normally would have been delegated to lower paid semi­skilled personnel. Costs for the indirect labor that participated inperforming these MPAF tasks were not included in the summary costsshown above to present a more accurate comparison.

Notwithstanding the above and taking into consideration the recommenda­tions discussed in Section 7.0 following, Hughes undertook a costingexercise to project the costs of a second MPAF of essentially the samedesign, but increased from three to ten building blocks (100 kW). Theestimated system BOS costs are shown in column three of the above costsummary table~ assuming fabrication and installation in 1983. Thesecosts were derived from vendor quotations and engineering costestimates. For example~ having now gained the experience of thefirst field installation of the 30 kW MPAF, the services of a generalcontractor would be eliminated in favor of direct subcontracting forthe field skills needed. More than 30 percent savings will be realizedfor this BOS element alone. The support structure front feet would beconnected using concrete foundations and stanchions. The PCC enclosurewould be more cost effective as its costs would be amortized over theten building blocks instead of three.achieved by factory assembly of the PVpanels.

Additional cost savings aremodules and support legs into

7.0 RECOMMENDATIONSProcuring and installing an actual modular photovoltaic array fieldbased on the AFOM study provided an opportunity to recognize improve­ments based on "hands-on " experience. Future array fields using the

34

AFOM study as a design base should incorporate the recommendationsdiscussed in the following paragraphs.

7.1 ELECTRICAL HARDWAREThe PV modules used in the MPAF system were essentially a custom solar

cell module design as defined by Hughes (Appendix A). Significantsavings would be realized through eliminating costs for special

production tooling, reductions in engineering liaison, and qualitycontrol surveillance by selecting a standard "off-the-shelf,"

qualified, commercial module (Ref. 2).

Fabricating and assembling certain parts in the factory rather than inthe field is more cost effective. For example, significant savings can

be realized by the factory assembly of modules and support legs intopanels. Additional savings would be incurred by reducing thelogistical problems attendant with the necessity for modules, frames,hardware, and personnel arriving at the array site in a timely manner.

Similarly, the Power Control Module (PCM) and the Power CollectionCenter (PCC) could also be fabricated, assembled, and tested by thesame vendor in his factory and shipped as a unit to the installation

site. This process would also reduce costs associated with high pricedelectricians performing electrical assembly tasks in the field and

would further reduce the risk of equipment damage due to assemblyerrors during field installation.

Because the MPAF system was essentially a prototype, much of the

electrical test equipment was borrowed and/or field adapted to performthe electrical checkout and commissioning verification tests. These

tests would be performed more efficiently using test equipmentspecifically designed for this modular array field.

35

7.2 FOUNDATIONSDuring the AFOM design study and analysis, the buried metal front footdesign, acting as both the foundation structural member and theelectrical earth ground for the array, was found to be the most costeffective. From the experience gained during this 30 kW MPAFinstallation, and, notwithstanding the cost of adding an earthelectrode grounding counterpoise, a foundation utilizing a concretecurb for both the front and the rear PV panel foundation was found tobe more cost effective. Smoothing trench bottoms to accept the earthfoot front foundations and the alignment of these foundations consumedmore installation time than planned. The installation would proceedmore quickly if both front and rear stanchions were bolted onto thealignment angles, placed into trenches, tapped into a level position,and the trenches filled with concrete.

The PV panel wind loads are concentrated primarily on the rearfoundations; therefore, less ballast is required for the front panelfoundation than for the rear panel foundation. The cost of the frontpanel concrete ballast is about the same as the cost of the metal earthfoot. Including the additional cost of PV panel groundingcounterpoise, the installation time saved will still result in anoverall less costly foundation.

7.3 FIELD INSTALLATIONAs discussed in Section 6.0, several semi-skilled tasks were performedby engineering personnel. Labor skills should be matched to theassigned tasks to reduce costs for quality control, installation,checkout and test labor.

Additional installation savings could be realized by eliminating thegeneral contractor and sUbcontracting directly for field constructionand electrical work. Also, consideration of seasonal factors whenselecting construction dates would minimize both lost time and expensesdue to inclement weather.

36

8.0 CONCLUSIONSUnder the PRDA programs sponsored by the DOE/Sandia NationalLaboratories, Balance of Systems (BOS) prices for installed fixed flatpanel photovoltaic systems prices were in the range of $400 to $500 persquare meter (1980$). The BOS cost for the installed ModularPhotovoltaic Array Field (MPAF) 30 kW array field at $118 per squaremeter (1980$) shows marked improvements over those of the PRDAexperience. This installed MPAF cost also compares favorably to theprojected costs developed under the Array Field Optimization and

Modularity (AFOM) design study when the differences in implementing thetwo are reduced to a common base, e.g., one of a kind versus adedicated factory, 30 kW versus 10 mW annual production, etc.

Further cost reductions from procurements of future intermediate size(20 to 500 kW) MPAF systems can be realized if the recommendationslisted earlier are implemented. For example, a preliminary costanalysis for the procurement and installation of a 100 kW MPAF showed a25 percent improvement in BOS costs as compared to the 30 kW MPAFinstallation.

In summary, the MPAF program verified that BOS costs developed underthe AFOM study were achieveable and that future reductions in BOS costscan be realized.

37

9.0 REFERENCES1. "Photovoltaic Array Field Optimization and Modularity Study,"

SAND81-7193, October 1982. Worked performed by Hughes AircraftCompany, under Sandia National Laboratories Contract #62-9188.

2. "Block V Solar Cell Module Design and Test Specification forIntermediate Load Applications - 1982," 5101-161, Jet Propulsion

Laboratory, February 1981.

38

APPENDIX I~

SOLAR CELL f10DULEPRODUCT SPECIFICATION

Al-2

r------------------~I I

: HUGHES:I ,

~------------------~HUGHES AIRCRAFT COMPANY

TITLE

PRODUCT SPECIFICATION

SOLAR CELL MODULE

NUMBER

11387

CODE IDENT NO.

82577

REV

B

TOTALPAGES

13

REVISIONSDATE APPROVED

DCN # 419696 A Revised per DCN # 419696----+----+

B Revised per EO iIlOlO

AUTHORIlY LTR DESCRIPTIONEFF

/0-18-92. 1tP~

4-22-83 ,J/5-e.I-----'--------J---L...-------------- .._ -----..._. --1

APPROVALSDATE DATE

If61lBCSJUNH

A3 -------

-- Preceding page blank

1.0

1.1

1.2

2.0

2.1

3-16-82

PRODUCT SPECIFICATION

SOLAR CELL MODULE

MPAF PROGRAM - SPEC. NO. SEP 11387

Scope

This specification defines the requirements for the design andconstruction of photovoltaic solar cell modules (herein referredto as the module) to be used for terrestrial applications.

Design Requirements

The module shall be designed to meet all requirements specifiedherein. Designated tests shall be successfully completed demonstrating

the ability of the module to meet all performance requirements of

this specification.

Deviations and Changes

Deviations from or changes to this specification shall not beallowed without written authorization from Hughes.

Applicable Documents

Government documents

The following documents s of the exact issue shown or of the current

issue when no date is shown s form a part of this specification tothe extent specified herein. In the event of conflict between the

documents referenced herein and the contents of this specifications

the detail contents of this specification shall be considered as

binding.

JPl #5l0l-l61 s Block V Solar Cell Module Design and Test

Specification for Intermediate load Applications - (February 20 s 1981)

A4

3.0 Reguirements

3.1 Functional Description

The module specified herein shall be used to convert solar energyto electrical energy in terrestrial applications.

3.2 Performance

The photovoltaic module shall provide the required minimum power

output when subjected to the specified test conditions.

3.2.1 Power Output

The minimum lot average current of the modules shall be 12.69 Amps

(66.0 watts) at 5.2 volts minimum when subjected to the test conditionsdefined in paragraph 3.2.2 No module shall produce less than 11.92

Amps (62.0 watts) at these conditions.

3.2.2 Test Conditions

Solar intensityCell temperature

1000 W/m2, AM 1.5

25° C minimum

3.3 Design

3.3.1 Electrical Design

All module circuitry, including output terminations shall be insulated

from the electrically conductive external surfaces. Leakage current

A5

3.3.1.2

3.3.1.3

3.3.1.4

3.3.2

3.3.2.1

shall not exceed 50 microamps when a potential of 3000 VDC is

applied between the external conductive surface and the output

terminals.

Electrical Interface

E~rh tprmin~l on the module shall be equipped with an AMP

SOLARLOK connector bus bar housing No. 121044-1. The polarity of

each socket shall be clearly marked in a permanent and legible

manner. Positive and negative terminals shall be located at

opposite ends of the module.

Bypass Diode

Each module shall have an integrated bypass diode electrically

connected across the output terminals. The forward direct current

capacity of the diode shall be greater than 1.1 times the module

short circuit current and derated for a temperature of 75° C. Thepeak inverse voltage rating of the diode shall be not less than

250 volts.

Reliability and Redundancy

The module shall meet or exceed the reliability and redundancy

requirements of Section II, Part B, Paragraph 4 of the referenced JPL

Specification 5101-161.

Mechanical Design

Moisture Protection

The module encapsulation matrix may be protected from moistureincursion with an impermeable barrier of metal foil having a minimum

thickness of .0015 inches.

A6

3.3.2.2

3.3.2.3

Geometry

Overall dimensions and hole locations shall conform to Figure 1.

Optical Surface

The illuminated optical surface of the module shall be temperedlow iron glass 0.188 inch thick minimum and shall conform to therequirements of Section II, Part C, paragraph 3 of the referencedJPL specification 5101-161.

3.3.2.4 InterchangeabilityAll modules shall be physically interchangeable.

3.3.2.5 Defects

3.3.2.5.1 Rejections

Modules with the following defects shall not be accepted:

a) Cracked or broken front surfaceb) Cracked or broken framec) Cracked or broken solar cells which:

1) Isolate a portion of a cell from either apositive or negative interconnect. Cornercracks having a hypotenuse less than 0.5 inchshall not be a cause for rejection.

2) Terminate or pass through or under an interconnectsolder joint.

3) Are caused by point impact.d) Cracked or broken interconnectse) Cells with unsoldered solder jointsf) Laminate voids greater than 1/4 inch diameter and

1 square inch total area per moduleg) Loose or broken terminalsh) Broken diodes or diode connections

3.3.2.5.2 Allowable Cosmetic Defects

At the discretion of Hughes, selected cosmetic defects which do notaffect form, fit, function or reliability may be permitted.

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3.4

3.5

3.6

4.0

4.1

Operational Life

The module shall be designed for an operational life of at1east 20 years.

Environment

As a minimum the module design shall be capable of withstandingexposure to the environmental tests defined in Section V of referenceJPL Specification 5101-161. The module shall also be capable ofmeeting the requirements of the Hot Spot Endurance Test of Section II,Part 8, paragraph 5 of the JPL Specification 5101-161.

Identification

Each module shall be legibly identified with the following:

a) Se11~r part numberb) Serial numberc) Current at test voltage

Quality Assurance Provisions

General

The product covered by this specification shall be subject toinspection and testing by both the seller and Hughes in accordancewith the quality assurance provisions of this section.

4.1.1 Interface Control Drawing (ICD)

Prior to the manufacturing of modules for this Hughes program,the vendor shall generate an IIInterface Control Drawing ll (lCD).This drawing shall identify the configuration, dimensions, partsand materials used in module fabrication. This ICD shall be submittedto HUQhes for approval prior to module fabrication. Any changes

thereafter affecting the performance or integrity of the module orthe ICD shall be submitted for approval to Hughes prior to intendedimple~entation of such changes.

A9

4.2 Reguirement Verification

4.2.1 Test and/or Inspection

Requirements specified in Section 3 of this specification and

listed in 4.2.3 (Requirements/Specification Matrix) shall be

verified by the applicable paragraphs of Section 4.

4.2.2 Certification

Requirements specified in Section 3 of this specification not

verified by inspection or test shall be satisfied by a submittalto Hughes of documentation showing evidence of conformance in the

form of data and/or test reports.

Reguirements/Verficiation Matrix4.2.3

Regui r'ements Titl eVerification MethodParagraph No.

3.2

3.3.1.1

3.3.1.2

3.3.1.3

3.3.1.4

3.3.2.1

3.3.2.2

3.3.2.3

3.3.2.4

3.3.2.5.1 (a-g)

3.3.2.5.1 (h)3.4

3.53.6

Performance

Electrical Voltage Insulation

Electrical Interface

Bypass Diodes

Reliability and Redundancy

Moisture Protection

Geometry

Optical Surface

Interchangabi1ityRejections

Broken Diodes or Diode ConnectionsOperational Life

Environment

Identification

AlO

4.4.2

4.4.3

4.4.1

4.2.2

4.2.24.2.2

4.4.14.2.2

4.2.2

4.4.1

4.4.1/4.4.4

4.2.2

4.54.4.1

4.3

4.3.1

4.3.2

4.3.3

4.3.4

4.3.4.1

Inspection and Test Methods

Hughes Source Inspection

The Hughes Aircraft Companys mays at its options provideinspection to monitor the seller's quality control procedures.The completed hardware may be source inspected by Hughes to assurethat the product conforms to all the requirements specified on

the applicable drawings and specifications.

Test location

Unless otherwise specified in the contract, qualification andacceptance tests shall be performed by the seller at the seller'splant. If the use of outside test facilities is required, suchuse shall be subject to approval by Hughes. Hughes shall have theright to witness, inspect and review all qualification and acceptance

tests.

Test Conditions

Unless otherwise specified herein, all tests shall be performed

at a temperature of 25 + 5°C.

Test Equipment

Test Equipment Accuracy

All meters, scales, thermometers and similar measuring equipmentused in conducting tests specified herein shall be accurate withinone percent of full-scale value except temperature which shall be

accurate within ~ 1°C. Full-scale deflection of meters shall notbe more than twice the maximum value of the item being measured.

All

4.3.4.2

4.3.4.3

Test Equipment Calibration

All test apparatus shall be calibrated at proper intervals and

records of such calibration shall be available for Hughes inspection.Hughes may examine the seller's test equipment and determine that

they are of the proper type and range to make measurements of the

required accuracy and are in calibration.

Solar Simulator

The solar simulator shall be capable of simulating air mass 1.5spectral conditions and a solar radiation intensity of 1000 W/m2•

The solar simulator intensity shall be calibrated and verified using

a Hughes approved standard solar cell which is traceable to a JPLcalibrated standard. The simulator may be either a constant xenon

light source or pulsed xenon type.

4.4 Acceptance Tests

4.4.1 Examination

Each module shall be visually inspected for compliance to the

following paragraphs: 3.3.1.2, 3.3.2.2, 3.3.2.5, 3.6, and theICD (4.1.1).

4.4.2 Electrical Performance

The seller shall test each module under the test conditions

specified in paragraph 3.2.2 to verify the output requirement of

paragraph 3.2.1. The solar simulator used for this test mustcomply with paragraph 4.3.4.3.

A12

4.4.3

4.4.4

4.4.5

A full current-voltage (I-V) characteristic curve is required

for each module. If a pulsed xenon type simulator is utilized,a minimum of 5 data points along the I-V curve is required including

short circuit current, current at rated voltage and open circuit

voltage.

Electrical Voltage Insulation Test

Each module shall be subjected to a "Hi-Pot" test conducted withthe output terminations shortcircuited. The leads from a suitabledc voltage power supply shall be connected with the positive lead

on the terminals and the negative lead on the module frame. Voltage

shall be applied at a rate not to exceed 500 V/sec up to the test

voltage of 3000 Vdc, and then held at this test voltage for at least

1 minute. The module shall be observed during the test and there

shall be no signs of arcing or flashover. Leakage current shall

be monitored during the test and shall not exceed 50 microamps.

Diode Verification Test

A diode verification test shall be performed on each module to insure

that none of the bypass diodes or their associated connections

have open or short circuits. The procedure for this test shall be

submitted to Hughes by the Seller for approval prior to performance

of this test.

Hughes Electrical Performance Tests

Upon preparation for shipment of each lot of modules Hughes willrandomly select one module for each 50 modules in the lot. These

selected modules will be retested by Hughes in accordance withparagraph 4.4.2. If the Hughes average values of power at the test

voltage for the sampled modules vary from the vendors values by

more than 2%, acceptance of the shipping lot shall be withheld pendingfurther testing and investigation.

Al3

4.5 Qualification Tests

The module defined by the lCD shall be subjected to QualificationTesting specified below.

4.5.1 Initial Tests

All modules selected for qualification testing under paragraphs4.5.2 and 4.5.3 shall be first subjected to and successfully pass

acceptance testing as defined in paragraph 4.4.

4.5.2

4.5.3

4.5.4

Environmental Tests

A minimum of four modules shall be subjected to the environmental

tests defined below in accordance with Section V of referenceJPL specification 5101-161. Module electrical performance measurements

(4.4.1) and visual inspection (4.4.2) shall be conducted after eachexposure. The tests shall be conducted in the order indicated:

1) Thermal cycle test2) Humidity-freezing cycle test3) Mechanical loading test4) Twisted-mounting surface test5) Hail impact test

Qualification Pass-Fail Criteria Test

The Environmental Tests' Pass-Fail criteria are defined by

Section III, Part B, Paragraph 7 of referenced JPL Specification 5101-161.

Hot-Spot Endurance Test

One module shall be subjected to a Hot-Spot endurance test for a cumulative

exposure period of 100 hours. The test shall be conducted using theprocedures described in Appendix C of the JPL Specification 5101-161.

Simultaneously with this hot spot endurance test the thermal configurationof the bypass diode assembly shall also be endurance tested. A separate

power supply shall be connected to the diode with polarity arranged to

drive a current equal to the module short circuit current through thediode. The test execution and inspection shall be the same as that

described in paragraphs(3C), (4), (5) and (6) of Appendix C of JPL

Specification 5101-161. The temperature of the diode shall be monitored

rluring the course of the hot spot endurance test. The sample shall satis~

A14

4.6

4.6.1

4.6.2

4.6.3

4.7

the criteria for qualification stated in Section III, Part B,paragraph 7 of the reference JPLSpecification 5101-161 at theconclusion of the test. The sample subjected to the Hot-Spotendurance test shall not be subjected to the environmental testsequence of paragraph 4.5.2.

Rejection and Retest - Production Modules

Rejected Modules

Modules rejected by Hughes shall not be resubmitted for acceptance without

furnishing full details concerning the rejection, the measure takento overcome the defects, and the prevention of their future occurence.Each rejected module shall be identified by a serialized rejection

tag. This rejection tag shall not be removed until rework requirementshave been complied with.

Defective Modules

Notwithstanding the warranty of individual modules, if, afterreceipt by Hughes, a large number of modules prove defective,such as to indicate a vendor manufacturing problem, the entire

lot may be rejected.Retest

Any unilateral changes from Paragraph 4.1.1 by the supplier inmanufacturing techniques, processes, materials, quality control levels,or type of manufacturing equipment shall be cause for complete

retest per paragraph 4.5 at no cost to Hughes.

Test Records

Records shall be kept of all tests and of applicable manufacturingdata, and these records shall be made available to Hughes. All

physical markings, defects and other visual characteristics shall

A15

be noted and recorded as a portion of the test record.

One copy of each module's I-V curve shall be included in theshipping container with the module. An additional copy of theI-V curve shall be sent to Hughes' Solar Energy Projects Office.

5.0 Preparation for Delivery

5.1 Packaging

The Seller shall package the modules into shipping containers whichadequately protect the modules from shipping d~mage. The shippingcontainers shall be palletized.

5.1.2 Module Current Grouping

Each module when tested at 5.2 volts per paragraph 4.4.2 shall be sortedinto current groups as shown below:

Current GroupABCDEFGHIJKL

5.2 Marking

5.2.1 Modu1 e

Current Output atFrom11 .27 AMPS11.5011.7512.0012.2512.5012.7513.0013.2513.5013.75Greater than

5.2 VoltsTo11.50 AMPS11.7512.0012.2512.5012.7513.0013.2513.5013.7514.0014.00

Each module shall be legibly identified with the following:

a) Module current and voltage measurement value.b) Current group.c) Seller's part number (if applicable) and serial number.d) Lot number if applicable.

e) Month and year of manufacture.

A16

5.2.2 Shipping Container

Each shipping container shall be ligibly identified withthe following:

a} Hughps part number {specification number}.b} Serialized container number.c} Quantity of modules in each current group

residing in the container.

6.0 Warranty

The contractor shall warrant that the solar cell modules offeredwill be free from defects in material, workmanship, and performancefor a period of not less than three {3} years after acceptance byHughes Aircraft Company. During the warranty period all modulesfound to have defects not caused by misuse or accident throughfault or negligence by Hughes or end user must be replaced atSeller's expense.

A17-18

APPENDIX B

GENERAL CONTRACTORSTATEMENT OF WORK

Bl-2

CONTRACTOR'S STATEMENT OF WORK

FOR

INSTALLING 30 KW PHOTOVOLTAIC ARRAY FIELDS

AT

SANDIA NATIONAL LABORATORIES, ALBUQUERQUE, NEW MEXICO

1) The site is located on the facilities of Sandia National Laboratories.Clear and flatten array field area. (Reference: Sandia location plan).

2) Perform site survey, location and staking of all trenches for areafoundation, power cabling, grounding counterpoise and Power Control Centerpad. (Reference: Hughes Drawings SEP 11340 and 11341).

3) Perform all trenching (Reference: Hughes Drawings SEP 11340 and 11341).

4) Install the photovoltaic panel structure foundation trench feet (Reference:

Hughes Drawing SEP 11330). This involves light raking so the trench bottom is

relatively flat and free of debris. Place the support structure feet onto

the trench bottom, bolting the stanchions to the feet and attaching thealignment bars to the stanchion tops. Check upright and level position andsecure. Backfill foot trenches except leave the trench ends clear for Step 9.

to allow for attaching the grounding counterpoise to the lower ends of thestanchion rows.

5) Install rear, concrete curb stanchions. This involves: Bolting long alignmentbars to installed and secured front stanchions. Place rear stanchions in trench

and bolt to long alignment bars. Attach short alignment bars and place theconcrete reinforcing rebar through the lower stanchion holes. Back stanchionswill be at right angles and level with respect to front stanchions and securedfor concrete pouring.

6) Assembly PV modules onto panels (Reference: Hughes Drawing SEP 11331). The

panel assembly must be assembled concurrently with foundation installation, so

that they will be ready for Step 11.

----- -

Preceding page blank

7) Form Power Control Center (PCC) concrete pad above ground (3 1 x 4 1 X 4" deep).

8) Pour concrete into concrete curb trenches and PCC pad form without allowingconcrete into the center cable trench.

9) Remove alignment spacers from support structure stanchion bars.

10) Attach the rear panel support leg to the rear stanchion.

11) Install photovoltaic panels. (4 men can install 1 panel). This involves

carrying the panel to the foundation stanchions, bolting the front PV panel

legs to the front stanchions, raising the panel rear and bolting in the rearPV panel support legs to the PV panel. Tighten all bolts.

12) Install J-Boxes. These units are approximately 8" x 12" X 12" and will beattached to the inner end of each PV panel row (Reference: Hughes DrawingSEP 11361 and 11362). The exposed panel side support channel at each inner

row end will be match drilled to fit the J-box mounting holes. Bolt on the

J-boxes to the side support channel (6 required for each 30 KW field).

13) Install Power Control Center onto the PCC concrete pad.

14) Attach risers to PCC and J-boxes.

15) Lay the field cables into the cable trenches and run through conduit risers

and up to the PCC and J-boxes. Check cable continuity and identifyappropriately.

16) Back-fill cable trenches to one-half depth.

17) Lay in and attach grounding counterpoises from earth-foot stanchion row ends.

18) Lay the central grounding counterpoise into the half filled cable trench and

attach to the grounding counterpoises from the earth foot stanchions and to the

ground point on the PCC.

19) Back-fi 11 groundi ng trenches.

B4

20) Assist Hughes in the interconnection of the PV modules and tie down loosewiring at outer array row ends. This involves simply plugging in factoryassembled jumper cable assemblies into adjacent modules. (Approximately 9

hours per 30 KW Array Field).

21) Assist Hughes in performing system electrical checkout. (Bid 30 hours for

the 30 KW array field).

Hughes will supply the following:

1) PV Modules.2) Foundations and structures per parts list and HAC Drawings

SEP 11330.3) J-Boxes, pre-assembled, ready for mounting and connecting.

4) PV array back panel harnesses.

5) Power cables, grounding cables, lugs and hardware.6) Power collection center (PCC) enclosure.7) PVC pipe (risers) and elbows, etc.

General Contractor will supply the following:

1) Manpower and equipment.

2) Concrete for trenches and PCC pad.3) Hisc. hardware.

Note: (Ref. Drawings SEP 11340 and SEP 11341)

There will be no fence or gate. See Sandia location plan.

B5

2x4 FOOTSOLAR CEUYOOULE

GALVANIZED -/":STEEL / 'CHANNELS ----------!~

METAL FOOTfOUNDATION

SUBARRAY STRUCTUREAND HYBRID FOUNDATION

B6

PVC CABLERISERS FORDIRECT BURIALCABLE

APPENDIX C

BLOCK IV TEST DATA

Cl-2

•11111111111 SOLAREX

October 18, 1982

Mr. George NaffHughes AircraftP.O. Box 9399Building A-I, MIs 4C 843Long Beach, California 90810-0399

Dear Mr. Naff:

During discussions with you we agreed to furnish you data on how ourBlock IV modules passed Block IV testing (Ref: JPL Document 5101-16, Rev. A)in the areas of mechanical loading, twisted mounting surface, and hail impacttests. Below are data which illustrate the characteristics and specificationsof the two modules:

MODULE CHARACTERISTICS

OUTSIDE DIMENSIONS (In)

GLASS THICKNESS (In)

CROSS SECTON OF LAMINATE

CELL SIZE (CM)

CELL GEOMETRIC ARRANGEMENT

FRAME STYLE

MOMENT OF INERTIA-LONGDIMENSION FRAME (In4)

MATERIAL - FRAME

SPECIFICATION

MECHANICAL LOADING

TWINSTED MOUNTING

HAIL IMPACT

SOLAREX CORPORATION

BLOCK IV

25 x 47.3

3/16

Glass-EVA, Cell-EVA-Tedlar

9.5 x 9.5

6 x 12

Modified 1/8" Sheet Metal

.39

Al 6063-T-6

10K Cycles, 50 lbs/ft2

See Either Spec

3/4" Diameter at 45 mph

C3

HUGHES

24.5 x 47.5

3/16

SAME

9.5 x 9.5

6 x 12

SEE INTERFACE CONTROL

.42

Al 6063-T-5

SAME

SAME

1" Diameter at 52 mph

-~~---

Preceding page blank1335 PICCARD DRIVE 0 ROCKVILLE, MD 208500301 94802020 TWX: 710 828 9709 0 CABLE ADDRESS: SOLAREX

October 18, 1982Mr. George NaffPage 2

The Solarex Block IV modules passed all these tests both at Solarex andat JPL (only JPL did the hail test). Dates are as follows:

MECHANICAL LOADING

TWISTED MOUNTING

HAIL IMPACT

SOLAREX

May 1980

May 1980

JPL

August 14, 1980

August 20, 1980

August 26, 1980

You will note that the Block IV specification calls for one module to betested to destruction by increasing the velocity of the iceball until theglass breaks, this occurred at 100 mph.

In view of the fact that the module geometry is virtually identical inboth modules, I have no hesitancy in recommending to you that you accept thesetests as sufficient validation. I therefore request that para. 4.5.2 3), 4),and 5) of HAC Spec. 11387 be considered as satisfied.

Sincerely,

SOLAREX CORPORATION

~o----~ ~ ,.J-~-James F. HoelscherProgram Manager

JFH:prf

cc:

Ms. Helen LopezBuilding A-I, M/SlB 708Long Beach, California 90810-0462

c4

APPENDIX D

ENVIRONMENTAL TEST REPORTS

Dl-2

ENVIRONMENTAL TEST REPORT

ON

HUGHES/SANDIA PHOTOVOLTAIC MODULES

DECEMBER 2, 1982

PREPARED BY

COLIN SHELLUM

QUALITY ASSURANCE

---------

Preceding page blank

1.0

2.0

3.0

4.0

5.0

6.0

7.0

TABLE OF CONTENTS

PURPOSE

INTRODUCTION

MODULE CONFIGURATION

INSPECTIONS AND ELECTRICAL TESTS

ENVIRONMENTAL TESTING

ENVIRONMENTAL TEST RESULTS

CONCLUSION

D4

PAGE

1

1

1

2

2

3

4

TABLE 1 -

TABLE 2 -

FIGURE 1 -

FIGURE 2 -

FIGURE 3 -

FI GURES 4-7 -

FI GURES 8- 9 -

TABLES

ELECTRICAL PERFORMANCE SUMMARY

ELECTRICAL VOLTAGE INSULATION TEST SUMMARY

FIGURES

QUALIFICATION TEST FLOW PLAN

THERMAL CYCLE TEST

HUMIDITY-FREEZE TEST

CURVES AFTER 50 THERMAL CYCLES

CURVES AFTER 10 HUMIDITY-FREEZE CYCLES

D5

1.0 PURPOSE

The purpose of this report is to document the performance

of photovoltaic modules manufactured by Solarex in compliance

with Hughes Specification 11387 and purchase order 05-234l68-DTS

"B" •

2.0 INTRODUCTION

Four modules were submitted to Block V environmental

testing as required by Hughes contract specification 11387. In

lieu of doing all tests required by JPL 5101-161, a letter was

submitted to the Hughes program Manager asking for waiver of the

twisted mounting surface test, hail test, and simulated load

cycle test. (See letter of October 18, 1982.) This report

deals only with the thermal cycling and humidity cycling tests.

3.0 MODULE CONFIGURATION

The configuration of the four modules tested (S.N.'s

1,2,3,4) is shown in Drawing D-l0015-03, 2x4 Demonstration

Module Interface Control.

D6

4.0 INSPECTIONS AND ELECTRICAL TESTS

Prior to thermal cycling, all modules were visually

inspected, subjected to hi-pot (3000vdc) tests, and electrical

performance (I-V) tests. These same tests were conducted after

each phase of testing.

5.0 ENVIRONMENTAL TESTING

The four modules selected for testing will be identified by

their serial number when referenced in test results (e.g., 1-4).

The test program consisted of three phases as per Block V

specifications (see Figure 1). In the first phase, all four

panels were subjected to the thermal cycle test of fifty (50)

cycles in which the temperature varied at a rate not exceeding

100oC/hour and with a period not greater than six hours/cycle

(from ambient to -40 oC to +90 oC to ambient). Module circuitry

was instrumented and monitored throughout the phase to monitor

continuity. At the termination of the 50 thermal cycles,

modules '2 and #3 were inspected and returned to the chamber for

an additional 150 cycles (total 200). The last 150 cycles were

run in the same manner as the first 50 (see Figure 2).

D7

Modules #1 and #4 were submitted to 10 humidity-freeze

cycles between -40 oC and +8S oC with 8SRH (t2.S%) maintained at

all temperatures except when impractical. During a cycle,

temperatures of +8SoC were sustained for a minimum of 20 hours

and -40 oC for a minimum of .S hours. The rate of change between

high and low temperatures was 100oC/hour maximum at temperatures

above OOC and 200 oC/hour for those below (see Figure 3). AS in

the first phase the module circuitry was monitored for

continuity.

6.0 ENVIRONMENTAL TEST RESULTS

Prior to testing, all modules were inspected visually and

electrically. Initial visual inspection of modules was

performed by Quality Assurance personnel following guidelines in

Specification 11387. The modules met the requirements of this

specification and normal Solarex inspection procedures for

rejections and allowable cosmetic defects.

Inspection after SO thermal cycles (10-12-82) revealed the

following:

A. Tears in Tedlar substrate of Module 2 due to one

module frame falling against its back (Tedlar) while in

DB

chamber or when removed. Tear #1 is approximately 2 inches long

and is positioned one inch to side of negative AMP connector.

This accident also caused the cell in front of tear to be

cracked/broken. Tear #2 is approximately seven (7) inches to

left and seven (7) inches down from Tear #1. Tear #2 appears as

a zig-zag of about one (1) inch in length.

Inspection after 10 humidity-freeze cycles for modules 1

and 4 (11-4-82) revealed the following:

A. Minor corrosion of diode enclosure assembly of Modules

#1 and #4.

Inspection after 150 thermal cycles (11-30-82) revealed no

significant changes or subsequent degradation in modules 2 and 3.

7.0 CONCLUSION

Electrical degradation was within accepted levels and there

were no signs of corrosion on cells, interconnects and other

module metallization.

Hi-Pot tests recorded allowable leakage current at 3000Vdc

and no arcing or flashover at all stages of testing.

D9

The Hughes modules showed relatively small amounts of

cosmetic degradation after submission to environmental testing.

Their overall final appearance remains excellent.

D10

HUGHES/BLOCK V TEST SUMMARYPARA- AFTER 50 AFTER 10 AFTER 150

SiN METERS BEFORE TESTINC THERMAL CYCLE~ H/F CYCLES THERMAL CYCLE~

ACTUAL ACTUAL % l::. ACTUAL % l::. ACTUAL % l::. ACTUAL % l::.

P (W) 64.08 63.44 -.87 62.19 -2.94max

V (V) 6.63 6.56 -1.05 6.66 +.451 oe

I (A) 13.08 13.70 fr4.74 13.08 0.00se

FF (%) 73.83 70.54 -4.45 71.37 -3.33

P 71.53 70.08 1-2.02 70.03 -2.09max

V 6.72 6.67 - .74 6.74 +.292' oe

I 14.48 14.65 -1.17 14.09 1-2.69seFF 73.52 71.67 2.51 73.67 +.20

P 63.00 63.68 ~1.07 62.68 -.50max

V 6.59 6.46 -1.97 6.64 +.753 oe

I 13.08 13.82 ~5.65 12.83 1. 91seFF 73.02 71.28 1-2.38 73.51 +.67

P 62.90 63.76 1.36 62.50 -.63max

V 6.63 6.53 -1.50 6~66 +.454 oe

I 13.61 14.06 3.30 13.31 -2.20se

FF 69.67 69.43 -.34 70 LLq +1.17

Pmax

VoeI seFF

Pmax

VoelaeFF

PmaxVoelseFF

Pmax

VoelaeFF

P T ~LE 1maxVoe HUGHE BMonu E ELECTR CAL P RFORMANC SUMM RYI iaeFF

Dll

AFTER 50 THERMAL CYCLES

10/12/82

AFTER 10 HUMIDITY-FREEZE

10/4/82

AFTER 150 THERMAL CYCLES

12/2/82

MODULE SiN

1

2

3

4

1

4

2

3

TABLE 2

LEAKAGE CURRENT (~A)

@ 3000V de

1.0

0.1

0.4

0.1

.34

2.16

0.0

0.0

ELECTRICAL VOLTAGE INSULATION TEST

D12

ELECTRICAL INSULATION

(HI-POT) TEST

3000V de

1ELECTRICAL PERFORMANCE TEST

AND VISUAL INSPECTION

1

,THERMAL CYCLE (50)

-40 to +90oC(ALL MODULES)

HonULESINSTRUMENTED/

MONITOREDTHROUGHOUT

.~ THERMAL CYCLE (150)ELECTRICAL PERFORMANCE TEST H -40 to +90oC

AND VISUAL INSPECTION (MODULES 2 & 3)'-- ..,.- .-.1

HUMIDITY-FREEZE (10), 8soC/8s\ RH/-40oC

I~

ELECTRICAL PERFORMANCE TEST

AND VISUAL INSPECTION

1FINAL ELECTRICAL

INSULATION (HI-POT)

TEST 3000V de

1EVALUATION OF TEST RESULTS

ENVIRONMENTAL REPORT

FIGURE 1

QUALIFICATION TEST FLOW PLAN

Dl3

1··------ MAXIMUM C'tC11 JlMl --------1

-U....=3z-I', - ICONnNUE FOR I

I, \ SO"S ~5.';~ES "\ II \ . J

II

rieure 2. Thermal Cycle Test (Shorter cycle time i. acceptableif lOOOC/hr maximum rate of temperature change i. Dotexceeded. Chamber may be opened at 2S-cycle 'intervals forvisual inspection.)

CONDITION

...-------15'!'~. 2.5% IH------------~I££ZINGI___I5~~ ·2.". ItH-

END OF CYCLE

r---­I CONnNUE­

/ FOR 10 CYCLES

I

20lfClh MAXIMUM ----.4

~------locfClhMAXIMUM------o\.

o

~tAl

~i 2S fo4'-- START OF CYCL!~=...i

... ... O.5h MINIMUM

1------20 MlNIMUM------t--. MAXIMUM--f

rieur. 3. Humidity-Freezinc Cycle te.t

(From JPL 5101-161)

D14

, ....~ ..1.6 ~.L "

~-:-.. _.- -~ :

.;;

:.+

; ,. w:. ...

1.4...... -~ ...;

- 1_ ,-10 .~- i

:~ ~.- .~:~-+- --

- ......

-~

-II--~

-~"""1

- -......

., - 14-,

-........ -.... -.. ..• ..

::~=-- '-:';"---

~_.-

1.2 .

..., ...~ ,--,r'::.l ~- :,~..~-

'''l' ......

-. ---'~

.- ...

--'r .~. -.'\.' - .

- ~-~

~,.- .....••. - .f-

~ ~ ..- - 4..- ::::

-.':_~ 6

...,---.-

...:>0 'SO;; .:..... ,......_ ~c:-~

_.~--~~. - - _ ~_:::::-;. -:-i

...- =-;;;: -;.,.

....

=--... .--.. .

12 14

.-- ...

..;

+' ......4 6 8 10

VOLTAGE (V)

Dale to:!l'-8WPaner T';1511~ Serial NOi.~--ll By 7J'£:>FORM 11140

oo 2

II~

.....;. 4-- ..--4­.-

fj

CORRECTIONS

25 DEGREES C AT ONE SUN

PANEL TYPE?HUGHESS/H?*2Voc:'?6.64Isc:?12.6V AT Pll'lax'?5.3I AT Pll'lax?11.3CEllS IN SERIES~PARALLEl?

12~6

CELL AREA IN SQ. C".?90.25WHAT REF USED?G-TOWNCALIBRATED CURRENT AT ONE SUN?10.43REF READING DURING TEST?8.96AMBIENT TEMP IN C?26STANDARD TEMP IN C?2~

..-

-- -

-+ SUN LEVEL DUR I HG TEST 85.91r-:TEMP DURING TEST 26 C

-- --

- -I-.~

.""-........ ..­.-+~.

---lit. - ......,..

.--',-

----~=.

_~I-'-

;.~.. :=,~. ~c

- 1-0-__ ~.

~ ~ ..

.•-1-'..............

FIGURE 5AFTER SO

THERMAL CY CLES

~- --~--~~~-:;:;=. ....-

• .+- .......

.+

1-

._­-

........,

1.0---'

~. ..- .--~

.. ..,~~.- -.~

0.8 -=::;-- ~~-

1.2

0.2

o ...0-<' .6 ~ ..- .....;.;... I::-.~..... ..- ..... --to-

(.) 0.4

.,

12o

o 2

~---U!~~IFORM 11140

4 6 8 10

VOLTAGE (V)

Oate"'-~"'tsv Panel T .....a ift. .."'P~ Serial No..#u-"U.c:...__ By 17t5D16U-

14

...,... 6

--

71.28 %9.8 "

6.4613.825.1612.3463.68

CORRECTIONS

2~ DECREES C AT ONE SUN

,..._ 1......--._

If. II

PANEL TYPE?HUGHESS/N1.3Voe?6.4Ise'?12.1V AT Pmax?5.1I AT Pm!*x'?18.8CELLS IN SERIES~PARALLEL?1.2~6

CELL AREA IN SQ. CM.?90.25WHAT REF USED?G-TO~lH

CALIBRATED CURRENT AT ONE SUN?18.43REF READING DURING TEST?9.11AMBIENT TEMP IN C?27STANDARD TEMP IN C?25

Fill factorEf f ic:iEmCY

VoeIscVPlrlaxI~lDax

Paax

SUN LEVEL DURING TEST 87.34TEMP DURING TEST 27 C

--\

-:.\;::l'lo--'

i~ ...• -lo. ...- ,:':;::; =

-- ,~,

-- -

-:\- ....-

-~--...."" - -"'l- -,- . -

- - - -- ~

--..

=1=: I~.

..~ -- ,....

- -

- -t..-.< ~_- -

.- ~

-+ ...+: .. :f--l .....

FIGURE 6AFTER. SO

THERMAL CYCLES.~--,,....;;..: --

-~- -'-'- -,-- - .....

. ~.' ":.,,..~ .,...

1.4

1.6

1.2 .

1.0

'.~~-~ "r' •0.8 f---

C 0.6 ~- ;to-

~XIOcccc:=u 0.4

0.2

---.-..,.. -.

-.-

12 14

By Tli5

-......J__

...,--4 6 8 10

VOLTAGE (V)

Date 10-5'-sr~ Panel Tvoe JLl1~ - Serial No~.=-~ _D17~FORM 11140

oo 2

lI:~~lI

tJf./1

CLI..•12 (c:

10

14 .....•......

8

.

=

12 14

.... .~

--< --n

.,.

.....-'-'

CORRECTIONS

2~ DEGREES C AT ONE SUNS

'Joe 6.~3~

~Ise 14.86 ~

VPID4IIX 5.23 ~

Ipllax 12.19 !Ii;

Paax 63.76 ~sFill factor 69.43 " ~

Efficiency 9.81 " soiii

SUN LEVEL DURING TEST 88.11 ...TEMP DURING TEST 26 C

- "~-' ._~

-~_. ': ....:~~._~ 6-. --'i~' -100.:.' ~~ h~- "".....

• ~-"'--. F=-o.. "",,",-_ •.....~ - - -- •.""",,,"-=:

. ~.;,:; _ '-S ..;;::::+- ......:.. >=-..... ~. - .,.~~.:;;

-~ 4..='.-

PANEL TYPE?HUGHESS/H?••Voe?6.5Isc'?12.4V AT Pmax'?5.21 AT Pllax'?18.75CELLS IN SERIESIPARALlEL?1216CELL AREA IN SQ. C".'?90.25J,JHAT REF USED?G-TOWNCALIBRATED CURRENT AT ONE SUN?1e.4~REF READING DURING TEST'?9.19AMBIENT TEMP IN C'?26STANDARD TEMP IN C'?25

--......;'

- -;"-!l

-- -.,. --!I;;;

-~- . ,.,l •

.,.- "'-'--

.,..

.-..: -

..... -"to ,-\--, -.... -

4 6 8 10VOLTAGE (V)

Date~PaneiT~-Di8J~ Serial N~..;.."i~__ By T/'l::)

: .. 4- l--

,"

-\"- -_:: ,,",'~4-

- .... ,..4--i""'o~ -

'. .,.-.

--

.,......

..... ,

-I-, -

.,. .~

-+~_t"

, ...

---

FIGURE 7AFTER SO

THERMAL CYCLES

- --- '__ :+;',!: '':: I::;::

=

... I-ri-'~

..... . ... -'+'

'-- .,.

.,~

.,...... :n

.- -+---

FORM 11140

oo 2

lIi~~1

1.4

1.2

1.0

0.8 1-__

0.2

14

--1""- _

87 72

12

__ .-1---

10

71.37 %9.57 %

6.6b13.885.3611. 662.19

.- ---- ....

8

CORRECTIONS

25 DEGREES C AT ONE SUN

PANEL TYPE?HUGHESS.....H?11Voc?6.6Isc'?11.5V AT PlAax?5.3I AT Pllax?18.2 ~

CELLS IN SERIES~PARALLEL?12~6

CELL AREA IN SQ. CM.?98.25WHAT REF USED?PSPCALIBRATED CURRENT AT ONE SUN?10.82REF READING DURING TEST?8.79AMBIENT TEMP IN C?27STANDARD TEMP IN C?25

VocI!'cV~Il~XIpllaxP"ilX

Fill factorEf f ici.raCY

SUH LEVEL DURING TESTTEMP DURING TEST 27 C

•

~f:-- "'t •

:...;...,.~ -

6

+

--'.

--

4

:=\=....- -"'~-~~__~ _ "l;.=:3 _-:;

t-: I=~. \:- .~~ .-,~:-;,;;:;..-;. ~- ~ - ,~~~

.- ..... "-'''':=~, .~ -....

.... ~1

~;...~.+

I:;':;" ~~ ~4-+

2

.-

-i.......__ ~~....

,...- --~

.,- -

· ••1- --

-

~.

=-.---...,~~ .._ ..J-.- ..........

1-_ _~I--l-

r;;..-=:;;: ----- -.w.:: I T"_";.. ..--- .- - --:::,.. ... -~::: •.-. ....... 1--:'- -- ..._ _ .~

~~ --- ..::: - . ~:::: :~-=t=- =:-;:; :~~ :.;,.~!!:--: - _._ __ !- .:'1•• 1_ .~;.. __ I...... -. I'lo.' I~ ~-.= ._I-~':::...~~' -f-..;..o.~_:"'I---

--1---- - - - ~-~- --I~--- '-_.,

........- ::.::;::;:-t---- .......,.- -. --,-

1-= .- -:-~ -- ...~- - .-..~~

FORM 111~

It:' IJJ!~~~

0.2

o

1.2

1.8

1.0

- 0.64(-~Zwa:a::::::»(J

1.8

1.4

1--.

1--- ..... .- t--'t -

PANEL TYPE?HUGHESS/N'?14-Voe?6.6Ise?11.7V AT PlDax'?5.3I AT PIUlX?10.25CELLS IN SERIES~PARALLEL?12,6CELL AREA IN SQ. C".?90.25WHAT REF USED?PSPCRLIBRATED CURRENT AT ONE SUN?10.82REF READIHG DURING TEST?8.79AMBIENT TEMP IN C?2.7STANDARD TE"P IN C?2~

CORRECTIONS

- f--O-'- ::.-. 1--" .... - .-:'r.--- - .""'r-.,/- -_~-- f- -..\,

. . -- ...- 1---'.... -- - .. - - 1\;:=_..:- ~_. ~ 1--. __,-.. f-- -'\.';' f-''- I::~

_ - :.:::n-::: -~ _.- I~

- -I·"'" .'It-

25 DEGREES C AT ONE SUN

Fill factorE f f i Cl(!'nCY

79.49 %9.62 "

6.6613.315.3611.6662.5

VocIscVp,,~y.

IpllaxPlnax

1­

--~-

.._'--1-_1-__

0.8

-I--'

... - f-- -- ...- -:---

.- ......~f-, - ..- SUN LEVEL DURING TEST 87.72TEMP DURING TEST 27 C

.-1---- --

....... -...;.~ 4.._"-,-

--'- f.,..;.

)~.,-­By((/

12 14

1-0--

•. 1---1-'-'-1---~r--'

10

Serial No. .,j~

j-". ......;. '-......

~ -- - ,

- --- .........,.

468VOLTAG~(V)

Date!t,-2c1-~,;panel T D20 (hjil,rc.

,. -:-rr.-'- -

~-

FORM 11'.c

o ~ .o 2

I&~I.............~....

0.2

0.4

rn AMECOMlitton College Park, Maryland 20740

ENVIRONMENTAL TEST REPORT

THERMAL CYCLING TESTAND

HUMIDITY FREEZING CYCLING TEST

FORSOLAREX CORPORATION1335 Piccard Drive

Rockville, Maryland 20850

PREPARED BY: 2<H~ 0 ~;7~ENVIIDNMENTAL ~INEERING

APPRCNED BY: ~ 1.c"C ~¥l1'·.'-C ENVI~MANAGERDATE J~-ll-/!J(.J, /

REPORT NO.621007-2621008-3

D2l

PAGE 1 OF 9

rnLitton

AMECOMREPORT NO.

P.O. NO.

621007-2

30013

DATE -.:l::...7~D..::e..:::c..:::em:;;.b::...e::.:r~1;.:::9..:::8.=2 _

PURPCSE OF T"..sI':

To determine the ability of the test item to withstand the test conditiondescribed herein.

Solarex Corporation1335 Piccard DriveRockville, Maryland 20850

MANUFACIURER'S TYPE OR ltD)EL NO.:

Two (2) large size Solar Panels in frames; identified by Solarex as U2and IF3.Two (2) small size Solar Panels in frames; identified by Solarex as Style SX.

DRAWIN:i, SPECIFlCATICN OR EXHIBIT:

Test conducted per Solarex Environmental Test Procedure, Section V, ParagraphA, Thermal Cycle Procedure.

QOANl'ITY of lTEXS TE'Sl'ED:

Four (4) Solar Panels

SEOJRITY CIM>SIFIG.TICN OF I~:

N/A

DATE TEST aMPIEl'ED:

27 November 1982

TEST CCNIXJCTED BY:

Litton Amecom Division

DISJ?a:iITICN OF SPECIMmS:

Returned to Solarex for electrical inspection.

ABSTRACl':At the conclusion of the thermal cycling test, the Solar Panels were visuallyinspected by James Hoelscher (Solarex representative) and witnessed byDean Cohen (Hughes Aircraft representative). The four (4) Solar Panels werereturned to Solarex for electrical inspection.

D229of2Page --=--~MIl30.1.-·Zl

rn AMECOMLitton College Park. Maryland 20740

REPORI' NO.

P.O. NO.

621007-2

30013

DATE -=l.J..7-'D:::.:e:::.:c;;.:;e~m;.:::b:.;:::e.:..r_l=_9.<.::8::;:;;2"___ _

Test Specimen

Four (4) Solar Panels:Two (2) large size panels in frames (#2, #3)Two (2) small size panels in frames (style SX)

Summary

This report certifies that the test specimens identified above havebeen subjected to the thermal cycling test prescribed in SolarexEnvironmental Test Procedure, Section V, Paragraph A, Thermal CycleProcedure. Test start date: 10/18/82. Test completion date:11/27/82.

Test Equipment

Type

TemperatureChamber

Manufacturer

Thermotron

Model No.

F-llO-CHV­25/ECA-8

SIN

7996

CalibrationDue Date

1/27/83

NOTE: The test equipment listed above was calibrated as requiredwith traceability to the National Bureau of Standards.Calibration records are maintained on file at this facility.

Test Procedure

The Solar Panels shall be subjected to thermal cycling in accordancewith the attached profile (Figure l), with the chamber temperaturevarying between -40°C and +90 0C. The temperature shall vary approxi­mately linearly with time at a rate not exceeding 1000C/h and witha period not greater than six (6) hours per cycle (from ambient to-40°C to +90 oC to ambient). The module circuitry shall be instrumentedand monitored to verify that no open circuits or ground faults occurredduring the exposure.

Test Results

The thermal cycling test of 150 cycles total was completed at 1335hours on 11/7/82. At 0900 hours on 11/30/82, the four (4) Solar Panelswere removed from the test chamber. A visual inspection was performedby James Hoelscher (Solarex representative) and witnessed by DeanCohen (Hughes Aircraft representative). At the conclusion of thetest, the four (4) Solar Panels were returned to Solarex Corporationfor electrical inspection.

D239of3Page-"""----

AMII30Il(,·azl

rn AMECOMLitton College Park Maryland 20740 DAILY TEST LOG

3001"3P.O. NO.-.......,;.~=:::.---:..--;:::~----

DATE TIME IJJG ENTRIFS

hLL'i.)fI-J) Y;lJln' i-hAl.kOA' 1I1Jr,,,,A Lrl tQJf C}LQJYYliJ.I~ )' I...:;:tj l\-r, (2) 1Jil'1rt/ fI,l,:V /)(I.Al.£Q..a ~V) 'OlrlJr1WJ /'#;;1- +;:- .~) ----f

J ( q j

\\-n-bl 1~t D

I - \ J

0 '730n~(,uJ . J

'- I I /

- \ v I -7 '

D I

PAGE 4 OF _9,,--_TEST BY: ~ha))W~bh.d:J·WIWESSED BY: ----------

fo-tB-8:z..DATEto 1I- "30- 8 kDATE _

.o.""1I30IlC6-.2) D24

P.O. NO.

rn AMECOMLitton College Park. Maryland 20740

REPORI' NO. __6~2=,1~0~0.L7--,,2~ _

30013

DATE 1_7_D_e_c_e_rn_b_e_r_l_98_2 _

11--·------- MAXIMUM CYCLE liMe -------·1

t'90

u..­.........,C)

o

,oct>C/h. IAAXIMUM

I ! I !

2 I

r\ ICONTINUE FOP. II \ SO or 200 CYCLES

I \ AS REQUIRED. "\ II ~ ..J

II

FIGURE 1

THERMAL CYCLE TEST

D259of5Page

--"'--AMI30S(6-IZ)

REPORT NO. _...::..6.=2:::..10::..;0:....:8_-.:;;.3 _rnLitton

AMECOMCollege Park. Maryland 20740 P.O. NO. 30345

PURPOSE OF TEST:

DATE --.:l::..7:..-::D...:e...:c...:e=mb.:....e=r~1~9...:8~2----

To determine the ability of the test item to withstand the test conditionsdescribed herein.

MANUFAC'IDRER:Solarex Corporation1335 Piccard DriveRockville, Maryland 20850

MANUFACl'URER'S TYPE OR M<DEL NO.:

Two (2) Solar Panels of the Prototype 2 x 4 demonstration model; identified bySolarex as #1 and #4.

DRAWI~, SPECIFICATIOO OR EXHIBIT:

Test conducted per Solarex Environmental Test Procedure, Section V, ParagraphB, Humidity Freezing Test Cycle Procedure.

QUANTITY of ITEMS TESTED:

Two (2)Solar Panels

SECURITY CIASSIFICATIOO OF ITEMS:

N/ A

DATE TEST COO'LETED:

29 October 1982

TEST <nIDUCTED BY:

Litton Arnecom Division

DISPOSITICN OF SPECIMENS:

Returned to Solarex for inspection.

ABS'I'RACl':

At the conclusion of the Humidity Freezing Test (10 cycles) the Solar Panelswere removed from the test chamber. A visual inspection of the two (2)panels was performed by James Hoelscher (Solarex representative) and witnessedby Dean Cohen (Hughes Aircraft representative). The Solar Panels were re­turned to Solarex Corporation for electrical inspection.

-Page 6 of 9 D26

AMII301l\6-'Z1

rn AMECOMLitton College Park. Maryland 20740

Test Specimen

Two (2) Solar Panels: Ul and U4Prototype 2 x 4 demonstration model

Summary

REPORI' NO. --.:.6..:;;2;::,,l0.:..,.0;...8;....-...:.3 _

P.O. NO. _-=3:.::0..:::.3.:...45~ _

DATE ...:1::..:7:.-::D~e...:.c..:;.em=b::..e:::.::r'___=1;..:9...:.8.;:;;2 _

This report certifies that the test specimens identified above havebeen subjected to the Humidity Freezing Cycling test prescribed inSolarex Environmental Test Procedure, Section V, Paragraph B, HumidityFreezing Test Cycle Procedure. Test start date: 10/19/82. Testcompletion date: 10/29/82.

Test Equipment

Type Manufacturer

Humidity/Temp- Tenneyerature Chamber

Model No.

T-30-UFR-I00550

SIN

4785

CalibrationDue Date

2/24/83

NOTE: The test equipment listed above was calibrated as requiredwith traceability to the National Bureau of Standards. Calibrationrecords are maintained on file at this facility.

Test Procedure

The Solar Panels shall be subjected to the Humidity Freezing testin accordance with the attached profile (Figure 2). The modulecircuitry shall be instrumented to verify that no open circuitsor ground faults occurred during the exposure.

Test Results

The Humidity Freezing test of 10 cycles was completed at 1230 hourson 10/29/82. At the conclusion of the test the two (2) Solar Panelswere removed from the test chamber. A visual inspection was performedby James Hoelscher (Solarex representative) and witnessed by DeanCohen (Hughes Aircraft representative). The Solar Panels were returnedto Solarex Corporation for electrical inspection.

Page _7l.-- of 9D27

rn AMECOMLitton College Park. Maryland 20740 DAILY 1EST LOG

DATE TIME10- 1'1-'i11...

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PAGE 8 OF 9TEST BY: CAt:lt-k<.<$ ~(J/uudiWI'INESSED BY: -----------

/0-'1-84 Il!DATE /0 -..;J..Z - 6"'-DATE ------

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30345

621008-3

P.O. NO.

REPORI' NO. ----'=="-""---=='---------rn AMECOMLitton College Park. Maryland 20740

17 December J982DATE ____----".............""'"""'.......,/.l.o.l.---,~~ _

CONDITION

85% + 2.5% RH "1~~E£ZINCI--85%,: 2.5% RH-

I~S85 ,..-----

IG I CONTINUE0_

100oC/h MAXIMUM I FOR 10 CYCLESau I0::> I....:£ 25 START OF CYCLE END OF CYCLE.......~............ 0~

:J00

200oC/h~ MO.XIMUM

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TIME(h)

FIGURE 2

HUMIDITY FREEZING CYCLE TEST

Page ~9,,-- of 9D29

....M.30.'.-.2)

rn AMECOMLitton College Park. Maryland 20740

ENVIRONMENTAL TEST REPORT

THERMAL CYCLING TEST

FORSOLAREX CORPORATION1335 Piccard Drive

Rockville, Maryland 20850

APP= BY: ~ (J. arrLENVIFbNMEitrALMANAGER

DATE _-,-/1_'.::...f...·....../ .....3=......~..... _

D30

REPORI' NO.

621007-2/3PAGE 1 OF 3

rn AMECOMLitton College Park Maryiand 20740

Test Specimen

REPORT NO. 621007-2/3

P.O. NO. 30013

DATE ~4;L..;\u.I-"au..nul"_']a;l.,rl...i¥-,......,I.l..;;9u8~3~ _

Four (4) Solar panels~ identified by Solarex as Panels #1, #2,#3, and #4.

Summary

This report certifies that the test specimens identified abovehave been subjected to the thermal cycling test prescribed inSolarex Environmental Test Procedure, Section Vi paragraph A,Thermal Cycle Procedure. Test start date: 9/21/82. Testcompletion date: 10/4/82. Duration of test: fifty (50) cycles.

Test Equipment

TemperatureChamber

!1anufacturer

Therrnotron

Model No.

F-IIO-CHV­25/ECA-8

SiN

7996

CalibrationDue Date

1/27/83

NOTE: The test equipment listed above was calibrated as requiredwith traceability to the National Bureau of Standards.Calibration records are maintained on file at this facility.

Test Procedure

The Solar Panels shall be subjected to thermal cycling in accordancewith the attached profile (Figure 1), with the chamber temperaturevarying between -40°C and +90 oC. The temperature shall vary approxi­mately lineraly with time at a rate not exceeding 100oC/h and witha period not greater than six (6) hours per cycle (from ambient to-40°C to +90 oc to ambient). The module circuitry shall be instru­mented and monitored to verify that no open circuits or groundfaults occurred during exposure.

Test Results

The thermal cycling test of 50 cycles total was completed on 10/4/82.A visual inspection was performed by a Solarex representative andthe four (4) Solar Panels were returned to Solarex Corporationfor electrical inspection.

Page 2 of 3 D31

REPORT NO. -l6;;L2~1.l...!0.L!0-.L"'.L1 -::.421-/~3 _rnLitton

AMECOMCollege ParI< MarYland 20740

P.O. NO. 30013

DATE -!:.L1;t.+..JJi.Ll;;Ia..lnI.l.11.ua;l..rL:Y~..I.]..::;9u.8:l.3~ _

1\\ ICONTINL'~ FO?

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FIGURE 1

THERf1AL CYCLE TEST

D323of3A""lU0516-&2.1

Page-=--

APPENDIX E

HOT SPOT ENDURANCE TEST REPORT

El-2

FINAL REPORT ON HOT SPOT ENDURANCE TEST

SOLAREX CORPORATION

February 1983

Hau D. Thai

John T. Riley

Phil Van Werkhoven

IN COMPLIANCE WITH HUGHES PURCHASE ORDER

NO. 05-234168-DT5

SPECIFICATION NO. 11387

E3-4

ABSTRACT

The Hot spot Endurance Test demonstrated solar module

capabili ty to withstand worst case field conditions. This was

accomplished by exposing typical panel cells to a cyclic worst

case thermal environment under electrical fault conditions. The

test cells and associated bypass diode successfully completed

100 hours of testing with no failures and continued nominal

operating character istics. These tests were conducted on Hughes

Solar Module Serial Number 0746026 in compliance with Hughes

Contract Number OS-234l68-DTS, and Specification Number 11387.

Detailed test methodology and results are attached.

ii

E5-6

TABLE OF CONTENTS

SECTION

ABSTRACT

LIST OF ILLUSTRATIONS

LIST OF TABLES

LIST OF SYMBOLS

1.0 INTRODUCTION

2.0 METHODOLOGY

2.1 pretest Measurements

2.11 Selection of A & B Cell Types

2.12 selected Cells

2.13 Diode Test

2.2 The Hot spot Endurance Test

2.21 Complete Test Arrangement

2.211 Test Cell Circuits

2.212 Timing Circuit

2.213 Temperature Control

2.3 Post Test

2.31 Light Curves

3.0 TEST RESULTS

3.1 CONCLUSIONS

E7

PAGE

ii

iv

v

vi

1

1

2

2

3

3

3

4

4

4

5

5

6

6

7

FIGURE

2

3

4

5

6

7

8

9

1 0

11

LIST OF ILLUSTRATIONS

Flow Chart of the Hot Spot Endurance Test

A Sample of 10 Cells on Hughes Solar Module

Block Diagram of Dark Reverse Voltage I-V

Curves Test

The Dark Reverse-Voltage I-V Curves of a

Sample of 10 Cells

3 Cells Nos. 46, 56, 58 Were Tested by the

Sun Simulator II (Before the Hot Spot Test)

Electrical Diagram of the Hot Spot Test on

the Bypass Diode

Dark Reverse Voltage I-V Curves on 3 Cells

Before and After the Hot Spot Test

Dark Reverse Voltage I-V Curves on 3 Cells

Nos. 46, 56, 58 After the Hot Spot Test

The I-V Curves of 3 Cells on the Sun Simulator

II (After the Hot Spot Test)

Bypass Diode forward Biased I-V Curve After the

Hot Spot Test

Variation of Maximum Temperature on Bypass Diode

vs Test Hours

E8

PAGE

9

1 0

11

1 2

1 3

1 4

1 5

1 6

1 7

18

1 9

TABLE NO.

I

LIST OF TABLES

Data on Three Test-Cells (Before and After

the Hot spot Endurance Test)

PAGE

8

lD

VD

lCT

VCT

TD

TJ

TC

TDMAX

TCMAX

TAlR

TBM

TOFF

RSH

RF

RREV

FF

EFF

PMAX

l rr

N

VpMAX

LIST OF SYMBOLS

Bypass diode current

Bypass diode voltage

Cell test current

Cell test voltage

Diode temperature

Junction box temperature

Test cell temperature

Maximum temperature on diode during one hour test

Maximum temperature on test cell during one hour test

Air temperature

solar module temperature

Maximum temperature level read on solar module set to

turn off the lR heater

Shunt resistance on cell

Diode forward resistance

Diode reverse resistance

Fill factor on cell

cell efficiency

cell maximum power

lrradiance

Number of cells on a string of a solar module

voltage at maximum power on a cell

E10

1.0 INTRODUCTION

The Hot spot Endurance Test was designed to stress the

components of a photovoltaic panel by exposing them to high

environmental temperatures during electrical conditions of

maximum power dissipation.

The test was proposed

5101-161. This specification

two (2) exceptions:

in JPL reference

was followed with

specification

the following

1. Additional testing was performed on the bypass diode.

2. Only type A cells were used, as there are no type B

cells in this panel.

three

post test

The test

evaluation, hot

Figure 1, page 9.

2.0 METHODOLOGY

consisted of

spot test,

(3) phases:

evaluation

pre-test

(Reference

The flowchart of the. hot spot endurance test (Figure 1,

page 11) shows us the ent ire test process. It includes three

main parts: The pre-test, hot spot endurance test, and the

post-test.

Ell

2.1 Pre-Test Measurement

The pre-test included the preparations of one bypass diode

and a solar module. The bypass diode test preparation has a

high potential test and electrical measurements on RF and RREV.

The solar module test preparation had the following steps:

L Sun Simulator II test on the solar module to give the

I-V curve for the entire module.

2. plots of dark rever se voltage I-V curves on 10 random

cells.

3. The selection of 3 cells based on the ir shunt

resistances.

4. Finally, the 3 selected cells were tested by the Sun

Simulator II to give their I-V curves.

2.11 Selection of A & B Cell Types

On the test module, a sample of 10 random cells were chosen

and their dark reverse-voltage I-V curves plotted (see Figure 5,

page 13). Test voltage VT was set equal to the maximum reverse

voltage that would occur across a single cell when test module

was driven to rated voltages by other panels or systems.

E12

On this particular module we found VT = -5.2 V D.C. and

ITest = 2.43 A D.C. (these values are based on the test data on

Figure 2, page 10). In this case all ten I-V curves belonged to

A types.

2.12 Selected Cells

From Figure 5, page 13, based on the cell shunt resistance,

three cells were selected for the hot spot test; cell no. 46

with highest shunt resistance, cell no. 56 with average shunt

resistance and cell no. 58 with lowest shunt resistance.

2.13 Diode Test

The bypass diode (Motorola IN3913) was mounted in its

associated junction box on the test module and included in the

endurance test. The pretest diagram can be found in figure 7,

page 15.

2.2 The Hot spot Endurance Test

The hot spot endurance test involved the diode and 3

cells. All tests were performed at the same time. The

accumulated on time for the electrical current and heater was

100 hours in one hour on, one hour off periods. The on current

for the diode was set at 15 amperes. The three cells were set

for VT = 5.2 volts D.C., and IT = 2.43 A D.C. with each of 3

light sources set for maximum power dissipation in the cell.

E13

2.21 Complete Test Arrangement

The entire test circuit diagram (Figure 8, page 16)

included:

1. A bypass diode test circuit

2. Three test cell circuits

3. A timing circuit

4. An infrared heater and its associated controller

circuit

2.211 Test Cell Circuits:

Each test cell was connected in series with a D.C.

power supply to drive these test cells to worst case

condition (VT = -5.2V, IT = 2.43A). Light illumination

level, test voltage, and current were adjusted

simultaneously for maximum power dissipation.

2.212 Timing Circuit

The timing circuit was connected to these circuits to

turn on the entire test system for 1 hour and off for 1

hour.

E14

2.213 Temperature Control

A thermocouple was implanted on the back s ide of the

solar module in an unilluminated area. This allowed the

proportional controller to maintain the temperature of the

panel as a whole at 49 0 C + lOCo The test current and

illumination increased the temperature of the three cells

under test above this background level.

2.3 post-Test

The post-test included the following steps:

The diode post-test

1. Measured RF' RRev resistances.

2. plotted the I-V curves.

3. performed the high potential

and its associated heat sink.

test on the diodef

Cells post-Test

1. Visual inspection on the fronts and backs of the

cells.

E15

2. Sun Simulator II tests each cell to get final I-V

curves.

3. Dark I-V curves on each cell to evaluate cell

shunt resistances.

2.31 Light Curves

All three test cells were Sun Simulator I I tested before

and after the Hot Spot test. The test results (Table 1, page 8)

indicate that test cell performance improved. Cell parameters

are shown in Figures 6 and 10, pages 14 and 18.

3.0 TEST RESULTS

Post-test results indicated that:

1. Visual inspection: on the back sides of the three (3)

test cells, the solder joints turned slightly brown.

This is believed to be caused by resin left when test

connections were made to the cells. This resin is not

present in normal panels.

2. Based on Table 1, page 8 cells efficiencies and peak

power were improved.

E16

3. Diode: Forward resistance went up slightly.

3.1 CONCLUSION

All three test cells and bypass diode passed this test.

E17

Table 1 The Sun Simulator II tests data on three test cells,before and after the Hot Spot test; (T . =25 deg.C)

aJ..r

Cell no. Cell parameters Before the test After the test Differences

46 Voc (V) .563 .553 -0.01Isc (A) 2.687 2.669 -0.02Pmax (w) .999 1.007 0.008Vpmax (V) .417 .419 0.002Ipmax (A) 2.394 2.406 0.012Eff. (%) 11. 07 11.12 0.05F.F. (%) 66.05 68.16 2.11

56 Voe (V) .568 .561 -0.007lse (A) 2.687 2.799 0.112Pmax (w) 1. 059 1. 074 0.015Vpmax (V) .428 .417 -0.011Ipmax (A) 2.475 2.576 0.101Eff. (%) 11. 74 11. 90 0.16F.F. (%) 69.41 68.35 -1. 06

58 Voe (V) .567 .558 -0.009Ise (A) 2.687 2.687 o.Pmax (w) 1. 019 1.023 i 0.004Vpmax (V) .417 .419 0.002Ipmax (A) 2.445 2.443 -0.003 a

Eff. (%) 11. 29 11.34 0.05 !i'J

"F.F. (%) 66.82 68.32 I 1.5 II

I I

E18

Figure 1 - Flowchart of the Hot Spot Endurance test

Hot Spot Endurance testprocedure of solar modul

Test preparatio~

Solar

Sun Simulator IItest on solar modul

Vtest,Itest

Hi-pot. tes~

Dark I-V curves onD.I0 cells

Cells'se~ection

Sun Simulator IItest on cells 46 56 5:

Hot Spot Endurance test

Diode test require- Cells test requirements:ments: 15A;100 hrs. Vtest=-5.2V,Itest~2.43Avs

light illumination; 100hrs.

post-test

Test performances,data on diode

Test performances,data on cells

.------*-----Conclusions

E19

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II

I 1._._.._-

I IIt;6 7 iI~ 30 '3; i"'f1. '13 ,~ I ~~ l' t7

i;

.'1

FIGURE 2

A SAMPLE OF TEN CELLS WERE CHOSEN TO DETERMINE

THEIR DARK REVERSE-VOLTAGE I-V CURVES

E20

(~dl bl1 the&::L1ti'T ie i.t Vl c:U"P.1i~+- "(r he1 dut),

:t5--:~-- r-~

________--l -J

FIGURE 3

THE BLOCK DIAGRAM OF THE PRETEST 11

TO DETERMINE THE DARK REVERSE-VOLTAGE I-V

CHARACTERISTICS OF SAMPLE OF TEN CELLS

E21

--,.._.1---,

f- - - r=-f-----

--r-'

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FIGURE 4

THE DARK REVERSE-VOLTAGE I-V CHARACTERISTICS

OF THE SAMPLE OF TEN RANDOMLY CHOSEN CELLSE22

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· j' .· 1- . FIGURE 8

THE DARK REVERSE VOLTAGE I-V CURVES

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4.2

-1

REPORTS DISTRIBUTION

DISTRIBUTION:

TID-4500-R66, UC-63a (551)

Department of Energy (3)Division of Photovoltaic Energy SystemsAttn: R. Annan

M. B. PrinceA. Krantz

Forrestal Bldg.1000 Independence Ave. SWWashington, DC 20546

Department of EnergyDivision of Passive and HybridAttn: Michael D. Maybaum, DirectorOffice of Solar ApplicationsWashington, DC 20585

Jet Propulsion Laboratory (6)Attn: R. V. Powell

E. S. DavisR. FerberK. VolkmerW. CallaghanR. Ross

4800 Oak Grove DrivePasadena, CA 91103

Jet Propulsion LaboratorySolar Data CenterMS 502-4144800 Oak Grove DrivePasadena, CA 91103

MIT-Energy LaboratoryAttn: E. KernE40.l72Cambridge, MA 02139

Solar Energy Research InstituteAttn: D. Feucht1536 Cole BoulevardGolden, CO 80401

SERI, Library (2)1536 Cole Boulevard, Bldg. #4Golden, CO 80401

Dist 1

Florida Solar Energy CenterAttn: H. Healey300 State Road 401Cape Canaveral, FL 32920

EPRI (:2)Attn: Edgar Demeo

Roger TaylorP. O. Box 10412Palo Alto, CA 94303

House Science and Technology CommitteAttn: Don TeagueRoom 374-BRayburn BuildingWashington, DC 20515

Tennessee Valley AuthorityAttn: J. McKibben715 Market StreetRoom 320Chatanooga, TN 37401

Department of EnergyTechnologies DivisionAttn: Dean C. GravesAlbuquerque, NM 87115

AF Energy Liaison OfficeDOE/Albuquerque Operations Ofc.Albuquerque, NM 87115

AFWAL/POOCAttn: Jack GeisWright Patterson AFBDayton, OH 45433

Argonne National LabAttn: Wayne Lark9700 S. Cass AvenueArgonne, IL 60439

Bonneville Power AdministrationAttn: Craig MortinsonP. O. Box 3621Portland, OR 97208

Brookhaven National LabsAttn: ·John AndrewsNational Center for Analysis

~f Energy SystemUpton, NY 11973

Department of EnergyDep. Asst. Sec. for Solar EnergyAttn: R. San Martin1000 Independence Ave., SW, Rm 6C026Washington, DC 20585

DROME-EAUSAMERADCOMRobert WilliamsFort Belvoir, VA 22060

NASA/LeRC (2)Attn: W. Brainard

Tom Klucher21000 Brookpark RodCleveland, OH 44135

Oak Ridge National LabAttn: Stephen KaplanP. o. Box XOak Ridge, TN 37830

USDA Forest ServiceAttn: John Hayes517 Gold SWAlbuquerque, NM 87102

Wind Systems ProgramAttn: Art EldridgeRocky Flats PlantP. o. Box 464Golden, CO 80401

A. T. Kearney, Inc.Attn: J. W. Egan699 Prince St.P. O. Box 1405Alexandria, VA 22313

Dist 2

Abacus Controls, Inc.Attn: G. A. O'SullivanP. O. Box 893Somerville, NJ 08&76

Acurex (2)Attn: M. Wool

R. Spencer485 Clyde Ave.Mountainview, CA 94042

ADTECHAttn: W. H. WarrenEnergy & Env. System Cntr.7923 Jones Branch Dr.McLean, VA 22102

Aerospace CorporationAttn: S. LeonardP. o. Box 92957Los Angeles, CA 90009

AlA Research CorporationAttn: George Royal1735 New York Ave. NWWashington, DC 20006

Allied ChemicalAttn: W. K. StempleP. O. Box 1021RMorristown, NJ 07960

American Power Conversion Corp.Attn: E. E. Landsman89 Cambridge StreetBurlington, MA 01803

Applied Solar Energy CorporationAttn: K. LingP. O. Box 1212City of Industry, CA 91745

Architects Collaborative46 Brattle StreetCambridge, MA 02138

Arco Solar, Inc.Attn: J. ArnettP. o. Box 4400Woodland Hills, CA 91365

Arizona Public Service Co.Attn: J. McGuirk411 North Central Ave.Phoenix, AZ 85036

Arizona State UniversityAttn: C. E. BackusCollege of EngineeringTempe, AZ 85281

Arthur D. Little, Inc.Attn: W. Peter TeaganAcorn ParkCambridge, MA 02140

Atlantic Research Corp.5390 Cherokee Ave.Alexandria, VA 22314

Avco Everett Research Lab., Inc.Attn: A. F. Byrnes2385 Revere Beach ParkwayEverette, MA 02149

Babcock & WilcoxAttn: R. L. WilliamsContract Research Div.P. O. Box 1260Lynchburg, VA 24505

BattelleAttn: Ray WattsP. O. Box 999Richland, WA 99352

Battelle Columbus Laboratories (2)Attn: D. Carmichael

G. Noel505 King AvenueColumbus, OH 43201

Bechtel Group Inc.Attn: w. StolteP. O. Box 3965San Francisco, CA 94119

Black & VeatchAttn: S. LevyP. O. Box 8405Kansas City, MO 64114

Dist 3

Boeing Engineering & ConstructionAttn: R. GilletteP. O. Box 3707Seattle, WA 98124

Booz, Allen, and Hamilton, Inc.Attn: C. Claiborne8801 E. Pleasant Valley Rd.Cleveland, OH 44131

Booz, Allen, and Hamilton, Inc.Attn: Jerry Rosenberg317 1st NWWashington, DC 20001

Boston Edison CompanyAttn: Michael Mulcahy800 Boylston StreetBoston, MA 02199

Burt Hill Kosar RittelmannAttn: John Oster400 Morgan CenterButler, PA 16001

California Energy CommissionAttn: Art Soinski1516 9th StreetSacramento, CA 95814

Chevron Research CompanyAttn: R. M. MooreP. O. Box 1627Richmond, CA 94802

Chronar CorporationAttn: G. SelfP. O. Box 177Princeton, NJ 08540

Clemson UniversityAttn: Jay W. LathropElectrical Engineering Dept.Clemson, SC 29631

Coast Guard R&D CenterAttn: S. TrenchardAvery PointGroton, CT 06340

commission of European CommunitiesAttn: G. Grassi200 Rue De La Loi1040 BrusselsBFLGIUM

Dayton ~ower & Light CompanyAttn: S. K. ArentsenP. O. Box 1247Courthouse PlazaDayton, OH 45401

Dayton T. Brown, Inc.Attn: Vincent LoscalzoChurch StreetBohemia, ~~ 11716

Dept. of Water and PowerCity of Los AngelesAttn: Chief EngineerP. o. Box IIILos Angeles, CA 90051

DSET Labs Inc.Attn: G. ZerlautP. O. Box 186Black Canyon StagePhoenix, AZ 86020

Dubin-Bloome AssociatesAttn: K. Raman312 Park RoadWest Hartford, CT 06107

Entech, Inc.Attn: Mark O'Neill1015 Royal LaneP. O. Box 612246DFW Airport, TX 75261

E. I. DuPont Co.Attn: E. Young6004 DuPont Bldg.Wilmington, DE 19898

Ebasco SVCS., Inc.Attn: J. D. NorrisTwo Rector St.New York, NY 10006

Dist 4

Energy AssociatesAttn: Walt Adams5109 Royene NEAlbuquerque, NM 87110

Exxon EnterprisesAttn: Virginia SUlzberger1251 Avenue of the Americas~ew York, NY 10020

Exxon Research Engr. Co.Attn: John P. DismukesP. O. Box 45Linden, NJ 07036

Florida Power and LightAttn: R. AllenP. O. Box 529100Miami, FL 33152

Frederick A. Costello, Inc.Attn: F. Costello12864 Tewksbury Dr.Herncon, VA 22071

General Electric CompanyAttn: E. MehalickAdvanced Energy Programs DepartmentP. o. Box 527King of Prussia, PA 19406

General Electric Energy Sys. Pro. DepAttn: J. A. Garate1 River Road, Bldg. 6Schenectady, NY 12345

Georgia Institute of TechnologyAttn: L.BantaTechnology Applications LaboratoryEng. Exp. StationAtlanta, GA 30332

Georgia Power CompanyAttn: G. BirdwellP. O. Box 4545Atlanta, GA 30302

German Aerospace Research EstablishmentAttn: Dr.C. VoigtAdvanced Programs DivisionPfaffenwaldring 38-40D-7000 Stuttgart 80WEST GERMANY

Gould inc.Attn: Hans Birch40 Gould CenterRolling Meadows, IL 60008

Hawaiian Electric Co., Inc.Attn: R. F. BellP. C. Box 2750Honolulu, HI 96840

Bittman Associates, Inc.Attn: L. D. Carter9190 Red Branch RoadColumbia, MD 21045

Holmes and Narver, Inc.Attn: W. C. Gekler999 Town and Country RoadOrange, CA 92668

HoneywellAttn: E. G. Zoerb1700 W. Highway 36Roseville, MN 55113

Hughes Aircraft CompanyAttn: G. NaffBldg. Al MS 4C843P. O. Box 9399Long Beach, CA 90810-0399

Intersol Power CorporationAttn: J. Sanders11901 W. Cedar Ave.Lakewood, CO 80228

JBF Scientific CorporationAttn: P. F. VeDuck, Jr.2 Jewel DriveWilmington, MA 01887

JSR AssociatesAttn: John Feuyl2280 Hanover St.Palo Alto, CA 94306

Dist 5

Kellam, Bird, Johnson Inc.Attn: J. Ayers612 North Park St.Columbus, OH 43215

Lea County Electric Coop.Attn: Pete FelfeP. O. Box 1447Lovington, NM 88260

Lockheed Missile & Space Co.Attn: Matthew McCargo3251 Hanover St.Palo Alto,CA 94304

Martin Marietta Corp.Attn: M. ImamuraP. O. Box 179Denver, CO 80201

Mass Design Architects and PlannersAttn: Gordon F. Tully146 Mount Auborn StreetCambridge, MA 02138

McGraw EdisonPower Systems DivisionAttn: B. OwensCannonsburg, PA 15317

Microwave AssociatesAttn: George AllendorfSouth AvenueBurlington, MA01803

Midwest Research InstituteSOLERAS ProjectAttn: H. Cranfill425 Volker Bl vd •Kansas City, MO 64110

Mission Research Corp.1720 Randolph SFAlbuquerque, N~ 87106

Mobil Solar Energy Corp.(2)Attn: K. Ravi

M. Ellis16 Hickory DriveWaltham, MA 02254

MONEGON4 Professional DriveSuite 130Gaithersburg, MD 20760

Motorola Gov. Electronics Div.Attn: .R. Kendall5005 East McDowell RoadPhoenix, AZ 85008

Mueller Associates, Inc.Attn: A. J. Parker, Jr.1900 Sulphur Spring RoadBaltimore, MD 21227

Mueller Associates, Inc.Attn: J. Shingleton600 Maryland Ave., SWSuite 430Washington, DC 20024

National Research Council of CanadaPhotovoltaic DivisionMontreal Roadottawa, CANADA KIAOR6

National Rural Electric CooperativeAssociation

Attn: W. Prichett1800 Massachusetts Ave., NWWashington, DC 20036

New Mexico Solar Energy InstituteAttn:!;; P.. ZwibelBox 3 SOLLas Cruces, NM 88003

~1MEFI

Attn: Gerald LeighCampus P. O.Box 25Albuquerque, NM 87131

Owens-Illinois, Inc.Attn: P. S. FriedmanP. o. Box 1035Toledo, OR 43666

Pacific Gas and Electric CompanyAttn: K. HarperGeneration Planning Dept.77 Beale St., Room 1389San Francisco, CA 94106

Dist 6

Pacific Power and LightAttn: Steve Carr920 SW 6th AvenuePortland, OR 97204_

Photon PowerAttn: D. Kilfoyle13 Founders Blvd.El Paso, TX 79906

Photovoltaic Energy SystemsAttn: Paul Maycock2401 Childs LaneAlexandria, VA 22308

PNMAttn: R. Frank BurchamAlvarado SquareAlbuquerque, NM 87158

Polaroid Corp.Attn: Larry KaufmanBuilding N-2XOne Upland RoadNorwood, MA 02062

PRC System Services Co.Attn: E. E. Paro7911 Charlotte DriveHuntsville, AL 35802

Progress IndustriesAttn: K. Busche7290 Murdy CircleHuntington Beach, CA 92649

Research Triangle InstituteAttn: R. A. ~fuisenant

P. O. Box 12194Research Triangle Park, NC 27709

Sl<IAttn: Y. P. Gupta8400 West Park DriveMcLean, VA 22102

Sacramento Municipal Utility DistrictAttn: M. Anderson6201 S. StreetBox 15830Sacramento, CA 95813

Salt River ProjectAttn: A. B. CummingsP.o. Box 1980Phoenix, AZ 85001

San Jose State UniversityAttn: Helmer NielsenDept. of Mechanical EngineeringWashington SquareSan Jose, CA 95192

SES, Inc. (2)Attn: Ted Russell

Al KeserTralee Industrial ParkNewark, DE 19711

Sir William Halcrow & PartnersAttn: M. R. StarrBurderop Park, Swindon SN4 OQDUK

Solar AmericaAttn: B. Spottswood1001 Connecticut NWSuite 728Washington, DC 20036

Solar America Inc.Attn: Leon Cooper2620 San Mateo NESuite HAlbuquerque, NM 87111

Solar Design Assoc.Attn: S. Strong271 WashingtonCanton, MA 02021

Solar DevelopmentAttn: P. Graven431 57th StreetDowners Grove, IL 60515

Solar Energy Information ServicesAttn: J. BerenyP. O. Box 19475Sacramento, CA 95819

Dist 7

Solarex CorporationAttn: H. Macomber1335 Piccard DriveRockville, MD 20859

Southern Cal. EdisonAttn: N. Patapoff2244 Walnut Grove Ave.Rosemead, CA 91170

SpectrolabAttn: G. L. McDorman12500 Gladstone AvenueSylmar, CA 91342

Spire CorporationAttn: R. G. LittlePatriots ParkBedford, ~~ 01730

Standard oil Company of OhioAttn: A. H. Clark3092 BroadwayCleveland, OB 44115

Stone & Webster Fngr.Attn: K. Hogeland245 Summer St.Boston, MA 02101

Strategies UnlimitedAttn: R. Johnson201 San Antonio CircleSuite 205Mt. View, CA 94040

TEAAttn: D. MahoneChurch HillHarrisville, NH 03450

Texas Instruments, Inc.Attn: Jules D. LevineP. o. Box 225303 Mis 158Dallas, TX 75265

Texas Tech UniversityAttn: E. W. KieslingDepartment of Civil EngineeringP. o. Box 4089Lubbock, TX 79409

The BDM CorporationAttn: W. Kauffman1801 Pandolph Pd. SFAlbuquerque, NM 87106

The BDM CorporationAttn: ~eorge Rhodes2600 Yale Blvd. SEAlbuquerque, NM 87106

The Bendix CorporationAttn: E. J. McGlinnBendix CenterExecutive OfficesSouthfield, MI 48076

The Fhrenkrantz GroupAttn: Stephen Weinstein19 West 44th StreetNew York, NY 10036

The John Hopkins UniversityApplied Physics LaboratoryAttn: W. R. PowellJohn Hopkins RoadLaurel, MD 20810

Theodore Barry & AssociatesAttn: J. Ayers1520 Wilshire BoulevardLos Angeles, CA 90017

Thermo Electron corporationAttn: R. Schar lack101 First AvenueWaltham, MA 02154

Travis-Braun and Associates, Inc.Attn: E. E. Braun4140 Office ParkwayDallas, TX 75204

Underwriters LaboratoriesAttn: W. J. Christian333 Pfingsten RoadNorthbrook, IL 60062

Underwriters Laboratories, Inc.Attn: Allan Levins1285 Walt Whitman PoadMelville, NY 11747

Dist 8

United Technologies Corp.Power Systems Div.Attn: Ramon RosatiP. O. Box 109South Windsor, CT 06074

University of ArkansasAttn: Jerry YeargauElectrical Engr. Dept.Fayetteville, AR 72701

University of Texas at ArlingtonAttn: W. DillonElectrical Engr. Dept.Arlington, TX 76019

UTLAttn: Shing Mao4500 W. MockingbirdDallas, TX 75209

Varian AssociatesAttn: P. Borden611 Hansen WayPalo Alto, CA 94303

Virginia Electric and PowerAttn: Robert CombsP. O.Box 564Richmond, VA 23204

Western Wood Products AssociationAttn: V. RioloYeon BuildingPortland, Oregon 97204

Westinghouse R&~ CenterAttn: R. K. Riel, 801-31310 Beulah RoadPittsburgh, PA 15235

William M. Brobeck and AssociatesAttn: W. W. Eukel1235 Tenth StreetBerkeley, CA 94710

WindworksAttn: H. MeyerRt. 3 Box 44AMukwonago, WI 53149

Wisconsin Power & LightAttn: Richard MorganP. o. Box 192Madison, WI 53701

Wyle LaboratoriesAttn: .R. E. Losey7800 Governors Drive WestHuntsville, AL 35807

62006220622162216221622162216221622162236223622362236224315184243141

v. L. DuganD. G. SchuelerE. L. BurgessJ. W. CampbellM. K. FuentesT. D. HarrisonR. G. LundgrenD. F. MenicucciM. G. ThomasG. J. JonesT. S. KeyH. N. Pos t ( 5 0 )J. W. StevensM. W. EdenburnW. L. Garner (3)M. A. PoundC. M. Ostrander (5)

Dist 9

*u.s. GOVERNMENT PRINTING OFFICE: 1984-0-776-027/4373