integrated residential photovoltaic array development...drl no. 154 drd no.ma-7 doeijpl 955893...
TRANSCRIPT
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DRL NO. 154 DRD NO. MA-7
DOEIJPL 955893 DISTRIBUTION CATEGORY UC-63
Integrated Residential Photovoltaic Array Development
QUARTERLY REPORT NO. 3
Report Date: August 30, 1981
PREPARED UNDER JPL CONTRACT 955893 PREPARED BY: G.C. Royal, Ill
AIA Research Corporation
1735 New York Avenue, N.W.
Washington, D.C. 20006
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DRL NO. 154 ORO NO. MA-7
DOE/JPL 955893 DISTRIBUTION CATEGORY UC-63
Integrated Residential Photovoltaic Array Development
QUARTERLY REPORT NO. 3
Report Date: August 30, 1981
PREPARED UNDER JPL CONTRACT 955893 PREPARED BY: G.C. Royal, Ill
The JPL Flat-Plate Solar Array Project is sponsored by the U.S. Department of Energy and forms part of the Solar Photovoltaic Conversion Program to initiate a major effort toward the develop-ment of low-cost solar arrays. This work was performed for the Jet Propulsion Laboratory, California Institute of Technology by agreement between NASA and DOE.
AIA Research Corporation
1735 New York Avenue, N·.W.
Washington, D.C. 20006
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This report was prepared as an account of work sponsored by the United States Government. Neither the United States nor the United States Department of Energy, nor any of their employees, nor any of their contractors, subcontrac-tors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness or usefulness of any information, apparatus, product or process disclosed, or represents that its use would not infringe privately owned-rights.
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ABSTRACT
This third quarterly report on a contract to develop an optimal integrated
a ~ residential photovoltaic array describes th~ optimization of a preferred
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design concept. This concept was selected from three discussed in the second
quarterly report (DOE/JPL 955893-2). Concept optimization was based on a
comprehensive set of technical, economic and institutional criteria. Remaining
concept development includes further analysis, optimization and prototype
fabrication. The preferred concept is .a set of subarrays using frameless
glass encapsulated modules, sealed by a silicone adhesive in a prefabricated
grid of rigid tape and purlins attached to the roof. This concept not only
features design modularity, low cost, parts minimization, and use of common
materials, it also allows integral, direct, or standoff installation. Key
electrical and mechanical concerns that affect further array subsystem
development are also discussed.
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TABLE OF CONTENTS
1· SECTION PAGE
-- I 1 Summary 1-1 . . . . . . . . . . . . 2 Introduction . . . . . 2-1 I 3 Technical Discussion . . . . . . . . . . . . 3-1
3 .1 Summary of Design Optimization . . 3-1 I 3.2 Module Design . . 3-4 I 3.3 Module Production 3-10
3.4 Array Hardware . . . . . . . 3-17 I 3 .4.1 Silicone Construction Sealants 3-18
3.4.2 Methods for Creating Support Frame 3-19 I 3.5 Array Hardware Fabrication . . . 3-23 I 3.6 Array Ins ta 11 at ion 3-30 . . . . . . . . .
3. 6 .1 Mounting Frame and Fl ashing . 3-33 I 3.6.2 Module Installation . . . . . . . . . 3-40
3.7 Laboratory Prototype Investigation . . . . . . 3-49 I 3. 7 .1 Fabrication . . . . 3-49 I 3.7.2 Frame Installation 3-51 . . . . 3.7.3 Module Ins ta 11 ation 3-53 I 3.7.4 Laboratory Observations . . . . 3-54
3.8 Field Prototype Development 3-63 I 4 Conclusions and Recommendations . . . . . . 4-1 I
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3-1
3-2
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3-12
3-13
3-14
3-15
3-16
LIST OF TABLES
Production Summary ....
Direct Material Inventory
Equipment and Utility Requirements
Module Size and Production Cost
Snow Fence Fabrication Material
Snow Fence Fabrication Material·
Array Installation Manhours
Installation Cost Elements •.
Installation Cost Elements .
Installation Cost Elements .
Maintenance Cost Elements
· Prototype Production Cost Esttmates
Prototype Module Direct Material and Equipment.
Subarray Hardware Fabrication Cost Summary •..
Page
3-13
. . . 3-14
. . 3-15
. 3-16
. . . 3-27
. 3-28
. 3-44
. 3-45
3-46
. 3-47
. . 3-48
. . 3-71
. 3-72
. 3-73
Subarray Hardware Direct Material, Labor and Equipment. 3-74
Subarray Installation Cost and Design Concept Cost Summary . • . . • . . . . . . . . . • . • • . • . 3-75
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.- 2-1
2-2
3-1
3-2
3-3
3-4
3-5
3-6
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3-9
3-10
3-11
3-12
3-13
3-14
3-15
3-16
3-17
3-18
3-19
3-20
3-21
3-22
LIST OF Fl GURES
BHKRA Concept .
Project Participants
Project Activity Diagram
Optimization Approach Outline
Array Design Issues
Module Moments of Inertia
Anthropometric Data
Module Handling Limits
. . . . . . .
Handling and Open-Circuit Voltage Conditions .
Module Production Sequence
Production Cost Rates
Snow Fence Module
Fabrication Requirements .
Snow Fence Fabrication Estimates .
Estimates of Field Installation
Array Wiring Plan
Side Rail Details
Ridge Rail Details .
Bottom Rail Details
Intermediate Rail Details
Laboratory Interface Control Requirements
Module Output Terminations ..
Prototype Nozzle Designs .
Prototype 4 kWp and 8 kWp Applications .
2 kWp Subarray Layout
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. 1-3
2-3
2-4
. 3-3
. . 3-5
. . 3-6
. 3-7
. . . 3-8
. . 3-9
. 3-12
. 3-13
. . . 3-25
3-26
. 3-29
3-31
.... 3-32
. 3-34
3-36
3-37
. 3-39
.. 3-50
. 3-57
3-59
. 3-64
. 3-66
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3-23
3-24
3-25
3-26
3-27
3-28
LIST OF FIGURES CONT'D
Field Prototype Module Characteristics
Field Prototype Circuit Characteristics
Field Prototype Cross-Section . Field Prototype Ridge Deta i 1 . . . . Field Prototype Rake Details .
Field Prototype Eave Details .
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3-68
3-76
3-77
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3-79
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SECTION 1
SUMMARY
This report discusses the status of a program to define an integrated
residential photovoltaic array. An optimum array configuration will satisfy
the needs of the earliest and largest market and provide electricity for the
least life cycle cost. The program emphasizes a systems approach to design
optimization that considers detailed electrical, mechanical, environmental,
economic and institutional factors. Further emphasis is the minimization of
cost drivers for these factors at several levels of annual production.
Sixteen design concepts were developed by eight teams. These concepts
considered both panel and shingle module types, as well as integral, direct,
standoff and rack mounting. Three concepts were selected from this group
based on proof-of-concept status, significance of innovative features, mounting
system reliability, and initial cost. This phase of the study is described
in the first quarterly report (DOE/JPL 955893-1).
The three concepts were then evijluated to confirm design trade-offs
through concept optimization in production, fabrication, design and specification
practice, installation, operation and maintenance of the array. Key innovative
features of the design concepts included: reduction in construction trade
limitations; adaptability to different mounting types; use of commonly available
materials; use of quick connect/disconnects; and, wiring harness elimination.
The single concept selected for further optimization allowed incorporation of
the significant innovative features without restraining choice of module size
and output or material selection to achieve acceptable system interface,
structural support, thermal design, safety, electrical circuit design,
reliability, and environmental endurance. This phase of the study is described
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in the second quarterly report (DOE/JPL 955893-2).
The selected design concept developed by Burt Hill Kosar Rittelmann
Associates (BHKRA), and illustrated in figure 1-1, uses nominal 2 kWp, 12' x
24' roof-mount'.sub~arrays. Each sub~array contains two branch circuits consisting
of nine modules that provide a Vno of 187.5 volts. The 2' x 8 1 frameless,
gasketless modules are adhesively bonded to cedar panel-rails. Branch-circuit
wiring between modules through the sub-array uses pre-assembled harnesses with
quick connect/disconnect while sub-array wiring is accomplished using
busbars. Preformed flashing is provided with each 11 sub-array kit 11 supplied
the job site. The sub-arrays can be installed in an integral or direct
mounting. Array subsystem costs are projected to be less than$ 407/m2 (in
1980 dollars) for a mature 1986.ma.rket with annual module production volume
of 50,000 m2. The resulting array design concept was fabricated in a partial
roof-section model to identify-additional array/roof interface concerns
Further model development is underway. This report summarizes concept
development and optimization achieved.
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Prefabricated mounting hardware is rolled out and nailed to roof sheathing or rafter.
Each row of modules is connetted then adhesively bonded to the mounting hardware.
Cover Glass EVA---------------------------. Solar Cell Circuii,----------~-EVA/Craneglass-------------Rear Cover (Al Foil/Tedlar)
Vertical Vane Plywood Sheathing Rafter or Truss Chord------
FIGURE 1-1. BHKRA CONCEPT
1-3
Adhesive Filled Joint
~--------Horizontal Rail
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SECTION 2
INTRODUCTION
~ The objective of this study is to develop optimal roof mounted arrays
for residences that provide energy for the least life cycle cost. Development
of an optimal array follows an integrated systems approach that considers
electrical, mechanical and environmental requirements, as well as such regional
variations as codes, construction practices and local costs. The resulting
array design will be fabricated in a final prototype partial roof/array model
to identify additional roof array interface concerns in production, manufacturing,
installation or maintenance. Program a~tivity is organized into the three
tasks listed below.
Task 1 - Alternative Desi.gn Concept Development
Task 2 - Preferred Design Concept Optimization
Task 3 - Prototype Roof/Array Section Fabrication
In Task 1 three (3) generic integrated photovoltaic array design concepts
were selected from a number of alternative concepts for residential applications.
An industry advisory panel was convened by the AIA/RC to select the most capable
teams from over 20 architects, engineers, homebuilders and designers to develop
a set of design alternatives.
A workshop held at the AIA/RC for the design teams was used to establish
a uniform starting point for the nine week concept design period. A series
of technical presentations were given for the following topics: system design;
module design; wiring and connector design; safety standards; and residential
roof construction.
At the end of the concept design period, a presentation was given by
each of the eight design teams to review the following characteristics for
each of the 16 concepts developed: appropriateness for earliest and largest
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market penetration; fabrication requirements, designed array output, modularity
and specification; array circuit .design, wiring and module connection;
panel/module attachment; installation requirements; operation and maintenance
requirements; and, costs. Three concepts were selected by the advisory panel
for further development, prior to selection of a preferred design for Task 2.
Design teams, wo~kshop participants, and advisory panel members are
identified in Figure {2-1).
Based on the results of Task 1, a single design concept was selected for
further analysis and development under Task 2. This selection followed a
presentation of the three developed concept designs at JPL on April 30, 1981.
Detailed production design development ·and engineering trade-off studies were
performed to further optimize the design for minimum life-cycle cost for the
installed array. Based on this detailed information, refined life-cycle cost
estimates were generated for annual module production levels of 50000 m2 area
at peak power. A set of drawings and specifications were prepared to permit
fabrication, installation and operation of the array design by a third party.
In addition, an initial full-scale p~rtial roof/array section was developed
to identify array/roof interface concerns.
The Task 3 activity will include the fabrication of a final full-scale
representative prototype section of the selected residential photovoltaic
array complete with electrical and mechanical interconnectors and array/roof
interface hardware. While this prototype section need not be electrically
operational, it will serve as a useful model to identify additional fabrication,
installation, maintenance and other concerns.
A block diagram of program activities·is shown in Figure (2-2). As of
this reporting date, all effort has been completed under.Task 2. In addition,
development of the final prototype under Task 3 has begun. This report
describes the results of the activities completed.
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DESIGN TEAMS
One Destgn Inc. Mountain Falls Rt. Winchester, VA 22601 CONTACT: T1m Maloney
Sunflower Solar, Inc. 1864 Sullivan Road College Park, GA 20337 CONTACT: Wayne Robertson
Dubin-Bloome Associates 42 West 39th Street New York. NY 10018 CONTACT: Bernard Levine
Solar Design Associates. Inc. Conant Road Lincoln, HA 01773 CONTACl: Steven J. Strong
Total Environmental Action, Inc. Church HI 11 Harrtsvi lle. NH 03450 CONTACT: Peter Temple
The Architects Collaborative, Inc. 46 Brattle Street Cambridge, HA 02138 CONTACT: Peter Horton
Mueller Associates, Inc. ·1900 Sulphur Spring Rd. Baltimore, HD 21227 CONTACT: Ted Swanson
Burt 11111 Kosar Rittelmen Associates
400 Horgan Center Buller, PA 16001 f.ONTACT: John Oster
WORKSIIOP LECTURERS
A 11 an levf ns Underwriters laboratories, Inc. 1285 Walt Whitman Road Melville, NY 11747
Carl Hansen Truss Plate Institute 8605 Cameron Street, Suite 148 Silver Sprtng, HO 20910 .
Daniel Arnhols AMP• Inc. P.O. Box 3608 Harrisburg, PA 17105
Leo Schrey AMP• Inc. P.O. Box 3608 llarrl sburg,. PA. 17105
Russell Sugimura Jet Propulsion Laboratories Hail Stop 510-260 4800 Oak Grove Drive Pasadena, CA 91109
Ron Ross Jet Propulsion laboratories 4800 Oak Grove Drive Pasadena, CA 91109
Jim Hoelscher Solarex 1335 Piccard Drive Rockville, HD 20850
Hugh Angleton HAIIB Research Foundation P.O. Box 1627 627 Southlawn Lane Rockville. HO 20850
FIGURE 2-1 PROJECT PARTICIPANTS
2-3
ADVISORY PANEL
Hugh Angleton NAHB Research Foundation P.O. Box 1627 627 Southlawn lane Rockville, HD 20'350 .
Steve Nearhoof Energy Design Associates 114 East Diamond Street Butler, PA 16001
Harvin Wiley Heery Energy Consultants. Inc.
880 West Peachtree St •• H. W.
Atlanta, GA 30309
Manfred G. Wihl Solarex 1335 Piccard Drive Rockville, HD 20850
Glen Bellamy lleery Energy Consultants. Inc. ·
880 West Peachtree St •• N.W.
Atlanta, GA 30309
Russell Sugtmura Jet Propulsion Laboratories Hail Stop 510-260 4800 Oak Grove Drive Pasadena. CA 91109
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1"ASK 1
·• Convene Advisory Conm1 ttee to revtew issues, approve draft of RFP
• Develop and distribute RFP • Develop LCC data requirements • Select 8 Firms; Advisory Comnittee
supplies technical assistance • Advisory Conmittee selects three
best concepts
TASK 2
• Advisory C011n1ttee review 3 designs· and selects optional design
• Subcontracting ftnn develop optional design in detail
, Arch. P.V. contractor, manufacturer and LCC consultant provide tech-nical assistance
• Advisory Cormittee review and ap-proves construction and specifi-cation documents
TASK 3
• Hodel Fabrtcator provides full-scale prototypical model based on a rep-resentative section based on con-struction documents I
PROJECT ACTIVITY DIAGRAM
INTEGRATED RESIDEHTJAL
rllOTOVOLTAIC ARRAY DEVELOPMENT
Figure 2-2
I Task 1 Documented I >-'-----~-------- ---------"\ Advisory Comnittee
Representative
AJA/RC
' Heery Energy Consultants:.! Energy Design Associates.;:;.]
NAIIB Research Foundation·"'~ {
Solarex, Inc. i
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~--------,-------~·· Entire Project Documented for JPL ~~-----------·
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SECTION 3.0
TECHNICAL DISCUSSION
.- 3.1 SUMMARY OF DESIGN OPTIMIZATION
The preferred design concept was revised to incorporate technical concerns
identified by the Advisory Panel in its review, together with certain appropriate
innovative features drawn from other concepts developed for the AIA/RC by its
design teams. Additionally,_ supporting studies on production, fabrication,
installation, operation and maintenance concerns appropriate for an annual rate -----· .
of module production ·of 50000 m2 area at peak power were also incorporated.
The following is a description of the optimization approach. The approach is
outlined i~ Figure 3-1.
AIA/RC and Solarex investigated module optimization appropriate to
handling, open-circuit voltage, and equipment requirements for annual production
volume of 50000 m2 area at peak power. Capital, labor and material costs
necessary to produce the optimized module at the referenced production volume
was determined. Mechanical and electr:ical characteristics of the module to
satisfy 20 year service life reliability, considering such stresses as
environmental exposure, hot-spot heating; and fatigue were verified.
AIA/RC and NAHB/RF investigated distribution assumptions appropriate to
the referenced annual module production that quantifies volume, plant, labor,
and material factors that apply to distributors/dealers responsible for
prefabrication of the array subsystem between the module manufacturer and the
installer. Installation assumptions based on homebuilder volume for crew
size, construction sequence, crew skill and wage, material/hardware use and
waste, and indirect costs were verified.
AIA/RC and EDA investigated system interface parameters (e.g., wiring
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requirements for wet/dry code approval, module mismatch, voltage window),
system operation parameters (e.g., allowable NOCT), and system maintenance
parameters (e.g., diagnostic and replacement requirements}, EDA assisted
BHKRA in incorporation of the results of the support studies, technical
concerns, and other optimization issues that arose during this effort.
BHKRA incorporated previously identified concerns relative to its design
concept, along with the results of supporting studies to minimize the cost
of the design concept. The following concerns were specifically addressed:
1) clarification of joint design relative to adhesive creep;
2) minimization of adhesive use;
3) reliability of adhesive bond developed;
4) module edge production;
5) clarification of busbar, module interconnect, and terminal design and approval;
6) protection of framing grid prior to installation;
7} resistance to wind uplift, transverse, and twist loads.
AIA/RC and HEC supported the engineering optimization using life-cycle
costing trade-offs. HEC validated the significance of the engineering trade-offs
devloped by BHKRA and EDA. The validation results were fed-back to BHKRA and
EDA for further iteration in design development.
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FIGURE 3-1 OPTIMIZATION APPROACH OUTLINE
Define Array Design Trade-offs
Module Geometry and Circuit Design
Array Alignment and Attachment
Array Connection and Cabling
Develop Criteria and Methodology for Design Trade-off
Generate Representative Designs and Trade-off Data
Synthesize Design Trade-offs
Analysis
Prototyping
Screen Design Trade-offs
Recommend Preferred Design for Fabrication
3-3
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3.2 MODULE DESIGN
An investigation was initiated to focus on the limit requirements for
maximum module dimensional configuration and maximum module output. Key
composite limitations in this study included: module size as a function on one
or two person handling; module size as a function of support conditions;
module output consistent w1th accepted open-circuit voltage levels; and,
module output consistent with practical packaging practices.
Module thickness for a reference glass encapsulation system was used to
generate tables of module moments of inertia for .areas between 1 .0 ft2 and
40.0 ft2. This tabulated data was· plotted to show all possible areal config-
urations equivalently (Figure 3-3).
Then, anthropometric data was compiled to investigate weight and hand-
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ling constraints for manufacturing and installation personnel. This data was I used to delineate module size and areal configuration limits based on static
weight, position of the module with respect to the human body's center of
gravity, and human torgue resistance .. The configuration with the maximum
module area was then selected (Point S-2 in Figure 3-5).
Alternative circuit configurati~ns were investigated for this dimensional.
configuration to determine maximum module output. Maximum module output was
limited by the composite requirements of open-circuit voltage of 30 Vdc at
-20°c, feasible packaging designs using 10 cm. x 10 cm. cells, and fault-
tolerant circuit design (Figure 3-6).
Support conditions provided by the frame assembly were rechecked to
assure that stresses in the glass superstrate were not excessive for the
redesigned areal configuration. Calculations indicated that the 2-sided
support provided by the support frame was adequate for the envisioned service
conditions.
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MODULE HANDLING SIZE REQUIREMENTS
IIANDLING BY 1 OR 2 PERSONS . . ANTIIROPOMETRIC LIMITS FOR LIFT AND TORQUB
C~NFIGURATIONS BETWEEN 1 FT2 AND 40 FT2
GLASS l!NCAPSULATION SYSTEMS . · · • EDGE TOLERANCE
MODULE SUPPORT SIZE REQUIREMENTS
HODEL CODB SERVICE LOADS 0
SUPPORT OPTIONS SIMPLE 4 ·SIDS UNIFORM
GLASS THICKNESS
MODULE CIRCUIT SIZE REQUIREMENTS
MODULARITY REFERENCE CELL CIJARACTERISTICS CIRCUITS PER MODULE
SAFETY 30 Vdc OPEN CIRCUIT VOLTAGE AT -20°c
RELIABILITY IIOT SPOT fiEA Tl NG
ARRAY CONNECTION
MAJOR CONCERNS I NCI.UDE: CONNECTOR PROFILH ANll LOCATION 11.t-.,
dry or wet) m: CONHl:CTOR CONNECTOR REUSP. J\Nll :\1:C"J!S!-: IIU I.I I\ SAFETY PROTECT 1 UN FROH l;X l'U:il:.l•
CONDUCTIVE PARTS ~
METIIODS: JUNCTION BOXES QUICK CONNECT/DISCONNECT QUICK PERMANENT CONNECT
ARRAY ALIGNMENT
MAJOR ISSUES INCLUDE: ARRAY LOCATION ON ROOF WITH RESPECT TO
ROOF PENETRATION ROOF SIZE RIDGE TO EAVE DISTANCE ESTABLISHMENT OF ANY NECESSARY DATUM CUMULATIVE PLACEMENT ERROR TOLERANCES
METIIODS: · BLOCK/BRACXET STRIP/CHANNEL GRID/MESH
ARRAY ATTACHMENT
MAJOR CONCERNS INCLUDB: LOCATION OF WEATIIERABLB SURFACB (l. e.,
either standard roof surface or module surface)
SUPPORT CONDITIONS LOADING CONDITIONS RBLIABILITY OF FASTBNING MBTHODS
METIIODS:
MECIIANiCAL FASTENERS PRESSURE FITTING GASXETS ADIIESIVBS .
ARRAY CABLING
MAJOR ISSUES INCLUOB: APPROVAL AND QUALIFICATION FACTORY vs. FI ELll Rl!QII I Rt:Hnns SAFETY PROTECTION FROM l!Xl'OSl!II
CONDUCTIVE PARTS
MDTIIODSf
SPLICE RIBBON MAT
FIGURE 3-2 ARRAY DESIGN ISSUES J_ ____________________________ _
3-5
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Moment of Inertia of one plate about axis X-X
- ' .,, x--· X ..... G')
d C: ::::0 rr1
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3: 0 c:, C: . r w m
I O"I 3:
0 3: ,,, :z --f u,
0 .,, ..... :z ,,, :::0 --f ..... >
DEPTH
·,
Sunadex (low iron glass) .12s•_• ____ j __ E.V.A. 2 layers P.V. Cells Craneglass E.V.A. Tedlar
0.030"--· o. 012"--.1::-------------------0.00511'----Jc================== 0.015"~~ .. r==================
.004"
TAB~TED HOWLB THIOHESS HOHENT or INERTIA CIH.4 1
ttott!NT ar DEPTH HOHEHT OP' DEPTH HCHDIT a, DEPTH HOHENT OP' d (IN.) tNBRTIA
4 d(JH.) INERTIA
4 d(IN.) INERTIA
tu IIH. 4~ d IJH.) INERTIA 4 lu UN. ) t,uc UN. I txx (IN. }
12 21., 24 220.0 36 742.6 48 1760.3
13 3S.O 25 248.7 37 806.2 49 1872.&
14 O.l 26 279.11 38 873.4 so 1989.6
15 S>. 7 27 lU.4 39 944.2 51 2111.3
16 &5.2 211 349.4 40 1018.7 52 2237.9
17 '78.2 29 3911. 2 u 1097.0 53 2359.S
1B 92.1 30 U9.I 42 1179,2 54 2506.l
19 109.2 31 474.2 43 1265.5 55 2HB.2
20 127.l 32 521.6 I 44 1355.t 56 2l9S.3
21 147.4 lJ 572.0 45 1450.4 57 2947. 7
22 lH.S 34 625.15 46 1549.3 58 3105.S
23 u,. 7 .. ; .. 3S I.-•'.-.. :.,, r~ 682.4 41 .-1452 .,.. ... 59 3269.0
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ANTHROPOMETRIC DATA
ANJHIIOPOMETRIC DATA :.. flANDING ADULT MAU: acco1111opar1u ., Tt or: " , MYI.J ... ..., PMVl,"''°"
....
•••
Wtlth1-IIUL8. ,,on-l'O.t• .. '"'"-·····
flGURE 3-4 ANTHROPOMETRIC DATA
3-7
Ct.lNIIING DATA
•• ,01e °" thle 11Mtl eCCDfflfllOdole1
99-.. U.$.A.edwll 1110let
. ........ I •• opl. l4ffll11.lfCllh
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HUMAN BTIIENOTH (lertNrl f1119IIGll'li
·:':llh == .!:== I 014 hond•ett .0 • u -••1t·o-aeeo •o.n-
• MIi [C!lql lmt•t
(!) 1 • ... t flH.. . ~ lf.E
I ---,IH. 11'-· , ....
UII ,OIICtl ITAlfDllfl
,~~ . .ri:.., :r:i.:.. h~::j• ~-~---1 i'. ~.!!..J. l, 1 "°"' lmrat
l>J0•401.&. er, foll9ufttf
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clo11 I~ ..bodr t- I
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3000
-.. 2500 z .:: < -... a: w z: - 2000 \6,, 0 ... a :c 0 :.:
~ 1500 "" t1 u
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S 1000 i
500
FIGURE 3-5. MODULE HANDLING AND OPEN-CIRCUIT VOLTAGE LIMITS
MODULE WEIGHT (LB.) 20 40 60 80 100 120 140
N
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5 10 15 20 25 30 35 HODULE AREA (FT.2)
FT.
MODULE WI.DTH •• 3 'fl ..
MODULE WI DTK • 2 FT.
MODULE CIRCUIT AREA
CONFIGURATION OUTPUT M2 "2 (WM .. ) 43S x lP 46.99 .43 4.63
435 X 2P 93.98 .86 9.25
43S X 3P 140.96 1.29 13.88
43S-x 4P 187. 95 1.72 18.51
43S x SP 234.94 2.15 23.13
43S X 6P 281. 93 2.58 27.76
43S x 7! 328.92 3.01 32.39 f
43S x 8P 375.91 3.44 37 .01
• Y0c < 30 vdc at -20°c • Haxtmum series str1ng • 43 cells
• 10 cm x 10 an cells
WEIGHT
(LB)
17.95
35.90
53.86
71.81
89.76
107. 71
125.66
143.62
1i11i1 Ila iillJ illll iiiil lllill lill8l liiiil 111111 Ill& liiiil lllii rlilll 11iiiJ 11111 ~ 111111 illlJ
-
w I
I.O
MAXIMUM ENVELOPE OIHENSJtNsl
, Envelope dimensions
FIGURE 3-6. CONCEPT INTERFACE CONTROL REQUIREMENTS ENCAPSULATION SYSTEM
80 cm x 161.45 cm (31.56 11 x 63.5611 )
, Cell to edge of glass 2.54 cm (1.00")
• Tolerance requirements on envelope.are met with standard glass tolerance levels
, Celi to ~, ass edge tolerance is reconmended as :!:. 0. 3113 cm (!. 1/8")
OUTPUT TERMINATIONS
AMP Solannate• quick connectors are installed on the back of each module. The Solarmate• quick connectors (female) are located 4.445 cm (1.75 11 ) from the long edge of the module and 5.08 cm (2.00 11 ) from the side or short edge 9f the mod~le.
The 5 kWp consists of 3 parallel branch circuits, each with 14 modules connected in series. Each branch circuit of 14 seriesed modules yields 263.2 volts and 7.1 amps at peak power. Peak array output is 263.2 volts and 21.3 amps.
ILLUMINATED (ACTIVE) SURFACE ENVELOPE DIMENSIONS, SHADOWING AND VJEW·ANGLE CONSTRAINTS
, Active array area -- 49. 12 m2
• Total array area-· 55.49 m2
• Active array area to total array area ratio-· .685
• Active module area* -- 11,695 cm2
• Total module area -- 12,943 cm2 · 1 Active module area to total module area ratio -- .904
. . *Accounts for 2 nm 1nterce11 spacing.
The mounting system has a zero profile angle to the top surface of the array with no shadowing or view-angle constraints.
1 l/811 (3.18 11111) Low Iron Tempered Glass , 2 • 0.01811 (0.45 11111) layers of EVA • PV cells • l - 0.005" (0.127 11111) layer of "Crane Glass" , 1 - layer of EVA , l - 0.006 11 (O. 152 mm) layer of polyethylene
Module perimeter of clean glass approximately 3/4" to l 11 (19.05 mm to 25.4 mm) edge of glass to encapsulation is recomnendP.d. ELECTRICAL PERFORMANCE (Pavg at NOC, vno; pp at_ 100 rrltl/cm2, ~s0c)
, Power• 133.5 Wat peak , Voltage a lij,8 Vat peak power , Amperage• 7.1 A at peak power , Open Circuit Voltage• 23.8 V , Short Circuit Current• 8.2 A
PROTOTYPE A: COS x JP, C DIODES"
----- ----- - --· I I
I \ \ \. I I j ) l I I ! l 1
- .- I .. -·-t J __ _ !
-
3.3 MODULE PRODUCTION
Module production and hardware fabrication trade-offs were investigated
for an annual cell production rate of 50000 m2 area at peak power. Based on
a 99% electrical yield for the initial reference module, rated peak-power
~ plant capacity is 6.5 MW.
The module manufacturing operating schedule was assumed to be 7128 working
hours, based on 3 eight-hour shifts per day for 6 days per week throughout the
year. Nine holidays and a one-week plant shutdown were also assumed. The
module production sequence illustrated below is illustrated by a one-line
block diagram in F.igure 3-7.
Cassettes containing pre-tested and sorted cells are transferred from a
cell storage area to the module production line at the cell interconnect machine.
After flux is applied to the cells, interconnect strips are soldered to the
front and rear contacts to complete the series strings. Parallel cross-ties
and end bus-strips are then applied. An open-circuit voltage acceptance test
is conducted on the cell string. Strings that fail are reworked, then tested.
After the open-circuit voltage test is passed, the strings are washed and
dried to remove residue accumulated in previous processing. The cell strings
are then stacked and tran~ferred to ·a storage area.
A primer is coated on the strings delivered from storage while the glass/EVA
front cover and EVA/Craneglass/Tedlar rear cover are separately assembled.
After the strings are placed in the front cover subassembly, final diode and
bus strip interconnections are completed. Then the rear cover is primed and
placed in final position. Each composite glass/EVA/cell circuit/EVA/Craneglass/
Tedlar sandwich is transferred to a buffer station until a full laminator load
is accumulated.
The lamination sequence consists of a 90-minute vacuum and curing-cycle.
Four laminations are used to achieve a throughput rate of one module every
five minutes. In the BHKRA concept, external output terminal connectors are
3-10
I I I I I I I I I I I I I I ··I· I I I I
-
attached to the bus strings after lamination. Each module is subsequently
tested for final certification of its electrical characteristics and
identification labels attached. The modules are then packaged for shipment
and transferred to the warehouse area.
Factory cost for several module sizes was calculated from the sum of
labor, material, equipment, floor space and utility cost estimates.
Production-rate cost relationships for the reference module are illustrated
in Figure 3-8. A profit and warranty allowance equivalent to 20% of the
module factory cost was added to yield a total FOB module factory price.
A summary of the principal FOB factory price elements for the reference module
is shown in Table 3-1 in'$1980/f12.
Direct material, which contributes more than three-fourths of the FOB
factory price, includes: cells; cover glass; EVA/Craneglass; Tedlar; primer;
solder; foil; diodes; sealant and connections. The basis for the direct
material cost used in the summary is listed in Table 3-2.
Factory equipment for module production includes the cost of a tabbing
and stringing machine; a rinse machin~; a string stacker; a primary station
for cells; an assembly station; four (4) laminators; a diode, bus and connector
installation station; and miscellaneous handling and conveyance equipment.
Utility services for module production include electricity, compressed air
and water. Equipment requirements for the reference module are shown in
Table 3-3. Equipment costs estimated for various module sizes are shown in
Table 3-4.
3-11
-
FIGURE 3-7 MODULE PRODUCTION SEQUENCE
CELLS
TAB AND STRING
.-
-::,.---~REWORK STRING
WASH STRI"NGS
STACK STRINGS
PRIME CELL STRINGS
LAYUP EVA TO GLASS I
ASSEMBLE CELL MATRIX I I
FINAL CONNECTIONS
I LAYUP BACK COVER
I FINAL LAYUP I
LAMINATE I TEST I
PACKAGE I 3-12 I
-
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~
a a a a a-
~ ,· fl! tJJ
a ' .
FIGURE 3-8. MODULE PRODUCTION COST RATES
Direct Labor= 7 Em lo ees * 7128 Hrs* 1.2 Utilization* $7.00 Hr Annual Production Rate
Labor Overhead= 150% * Direct Labor
Direct Materi a 1
Direct Material Overhead= 3% * Direct Material
Equipment= 907 ODO Initial Cost 5 Yr Life * Annual Production Rate
Floor Space= $5.00 ft2 * 4400 ft2 Annual Production Rate
Utility Costs
Electricity= 30 kW* 7128 Hrs* $0.056 kWh Annual Production Rate
Compressed Air= 6.3) cfm * $20.00 cfm 5 Yr Life* Annual Production Rate
Chilled Water =
TABLE 3-1. MODULE PR.ODUCTION SUMMARY
ELEMENT Cost ($1980/M2)
Direct Labor (7 Employees@ $7.00/Hr) Labor Overhead (150S of Direct Labor) Direct Material ($341.22/Module) Material Overhead (3% of Direct Material) Equipment ($907,000@ 5 Year Life) Floor Space (4400 Ft2 @ $5.00/Ft2) Total Utilities
Subtotal Cost Profit (201 of Cost, including Warranty)
TOTAL FOB FACTORY PRICE
• Module Size= 80 cm (31.6 in.)* 161.5 cm (63.6 in.) • Annual Module Production= so.ooo.rf
3-13
8.38 12.57
264.10
13.23 3.63 0.44 0.07
302.42
60.48
362.90
-
.-
___________ ___,,I TABLE 3-2 MODULE DIRECT MATERIAL INVENTORY
ELEMENT UNIT COST NUMBER OF ($1980) UNITS
Solar Cells 2.30/Wp 133. 5 Wp ( 1 0 cm x 1 O cm ) (l20 cells)
Tempered Glass Cover 14 .68/m2 ,.292 m2 (0.125 in.)
EVA/Craneglass (1. 27 mm)
4. 77/m2 1.292 m2
Primer 0.01/ml 129 ml
Solder-Plated Cu Foil 3.78/m2 0.15· m2 (500 m)
Solder-Plated Cu Foil 20.00/m2 0.02 m2
Solder 0. 31 /g 6.5 g
Aluminum Foil (50 m) 0.47/m2 1.292 m2 .
Bypass Diode 0.70/diode 4 diodes .
Butyl Sealant 0. 01 /g 44 g
Solarlok, Female 0.45/ 2 connectors connector
TOTAL
• Module Size= 80 cm (31.6 in.)* 161.5 cm (63.6 in.) • Annual Module Production = 50,000 ~12
3-14
TOTAL COST ( $1980)
307.05
18. 97
6 .16
1.29
0.57
0.40
2.03
o. 61
2.80
0.44
0.90
341 .22
I 1·
I
I
-
n n a a a a ~ -
~
D Im
a a
.-
TABLE 3-3 MODULE EQUIPMENT AND UTILITY REQUIREMENTS
SERVICE ELEMENT COST ($1980)
El ec (kW) Air (cfm)
Tabbing/Stringing 500,000 3.0 6.2 .. _ .. . .
-Rinse Machine 70,000 1.0 ---
String Stacker 10,000 0.5 I ---
Cell Priming 50,000 0.5 ---
Assembly Station 15,000 0.5 ---·--·-·- ... ··- -··
..
Lamina tors 160,000 24.0 0. 1 -·· -··· - . ..
Diode ,:erminal, Bus & 42,000 1.0 ---Connector Installation
Miscellaneous Handling 60 ,oo.o 0.5 ---._ ..... _ ..
TOTAL 907,000 30.0 6.3 -·
, Module Size= 80 cm (31 .6 in.)* 161.5 cm (63.6 in.)
• Annual Module Production= 50,000 M2
3-15
Water (gpm)
2.3 .... _
--· ..
. 12. 1
---
---
----. .. -
1.8
---
---..
15 .4
-
TABLE 3-4. MODULE SIZE AND PRODUCTION COST
SERVICE ELEMENT COST ($1980)
El ec (kW) Air (cfm) Water (9pm)
Tabbing/Strfngfng 375,000 3.0 6.2 1.5
Rfnse Machine 60,000 1.0 --- 12.1 String Stacker 8,000 0.5 --- ---Cell Priming 45,000 0.5 --- ---Assembly Station 12.000 0.5 --- ---Laminators 120,000 24.0 0.1 1.8
Diode Tenninal, Bus & 37,000 1.0 --- ---Connector Installation
Miscellaneous Handling 60,000 0.5 --- ---'
TOTAL 717,000 30.0 6.3 15.4
• Module Size c126 cm (49.6 in)* 67 cm (26.3 in)
• Annual Module Production• 50,000 M2
SERVICE ELEMENT COST ($1980)
Elec (kW) Afr (cfm) Water (9pm)
Tabbing/Stringing 500,000 3.0 6.2 2.3
Rinse Machine 70,000 1.0 --- 12.1 String Stacker 10,000 o.s --- ---Cell Priming 50,000 0.5 --- ---Assembly Station 15,000 0.5 --- ---Lamina tors 160,000 24.0 0.1 1.8
Diode Tennfnal, Bus & 42,000 Connector Installation
1.0 --- ---Miscellaneous Handling 60,000 0.5 --- ---TOTAL 907,000 30.0 6.3 15.4
• Module Size• BO cm (31.6 fn.) * 161.5 C111 (63.6 fn.) • Annual Module Production• 50,000 If
3-16
I I I.
"
I I I I I I I I I I I I I I I I
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~ I I
~ ' I
3.4 ARRAY HARDWARE
The support frame design is a radical concept that uses manufacturing
processes to reduce on-site labor. In the factory, the entire framing system
is pre-assembled into a large mat- or net-like structure. This grid has nine
stiff wood, aluminum,. or steel rails spaced parallel at the module width.
a Flexible metal tapes, approximately 2" wide, are connected to the rails perpendicularly at the module length to form a grid. The framework is thus
~ pre-spaced for installation on site. This stiff/flexible mat is then rolled
a ' . ~ ~
a . .
~ lh.ll
~ klJ
~ ' L .
up like a snow fence. Two 16 foot bundles can be rolled out on a roof to
support one 5 KW array. A roll of this pre-assembled framework is carried
to the ridge of the roof in a direct mount application. The stiff channels
run horizontally across the roof. The top rail is attached in place parallel
to the ridge and then the bundle is allowed to uncoil by rolling down to the
eaves. The grid or mat is thus loosely set in place before attaching it to
the roof. The grid is squared against a side rail and tacked in place. To
insure that the channels are all set at the proper distance, the flexible
tape vertical members are pulled to their maximum length and then tacked at
the bottom. (The tape should not str.etch so as to distort the framing
dimensions.) When satisfied that the grid is well-placed, the workmen
mechanically fasten the stiff rails to the plywood surface. Resilient stops,
attached to the rails in the factory, prevent the modules from sliding off
the grid until the silicone develops sufficient adhesion. The vertically I
running metal tape acts both as a spacer ·and also as a backing material for
the sealing of the vertical joints between the adjacent panels. The tape is
crowned, and when rolled out can span without sagging; it fits tight ag~inst
the underside of the two glass edges at the vertical joint.
The tape members also enhance alignment of the grid.because a limited
moment connection could be formed at its jointure to the rails, and thus be
3-17
-
pre-squared as it is uncoiled. Only minor adjustments then need be made to
produce a truly square grid pattern.
3.4.1. Silicone Construction Sealants
The construction sealants can be classified in two main categories:
acid/nonacid and high modulous/low modulous. (Two part compounds have been
neglected; narrow joints are assumed.) Acid types liberate acetic acid during
curing and will corrode copper and certain other substrates, and will react
with salt residues from neoprene. Hazardous levels of exposure to acetic
vapors set by OSHA are 10 ppm. Nonacid types liberate alcohol and have wide
substrate compatibility. High modulous sealants have greater strength, but
allow only+ 25% movement with respect to joint width. Low modulous sealants
are as much as 50% weaker but offer as much as+ 50% movement with respect
to joint width.
Both General Electric and Dow manufacture silicone, but the GE product
names are used here to donate the different types available. The GE 1200
series is a high modulous acetoxy (acid) standard grade sealant used in .
conventional glue-on glazing systems and can be used as well as for attaching
modules to the frame. Its high strength makes it attractive, but suitable
substrates must be found or proper primers chosen to cost difficult-to-bond
surfaces to ·develop proper adhesion. Exposure to copper must be avoided. It
develops a tack-free surface in five to ten minutes and cures in 24 hours.
The 2000 series is a low modulous alkoxy (nonacid) sealant whose strength may
be sufficient for our purposes. It has wide substrate capability, greater
joint movement, and is noncorrosive. It develops a tack-free surface in four
hours and cures i~ two days. The 2400 series is similar in chemistry to the
1200 but has a lower modulous.
The RTV 100 series is nearly identical to the 1200 product, but is more
3-18
I I 11·
I I I I I I I I I I I I I I I I
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expensive. The RTV-116 is a low odor noncorrosive silicone rubber that is
roughly equivalent to the 2000 series construction sealant. All of these
sealants have joint width limitations in the neighborhood of 3/8 11 and cannot
be used in totally confined spaces because contact-with air is required for
curing.
3.4.2. Methods for Creating Snow-Fence Support Frame
The flexible metal tape which permits the support frame to be coiled for
easy shipping and quick installation is central to the concept. The rails,
however, can be formed from a number of materials either off the shelf or
completely designed and developed. Three suitable materials for this application
are wood, aluminum, and steel.
The use of wooden horizontal rails instead of metal ones can be justified
for several reasons. First, it perfectly integrates with the materials and
methods of sjngle family residential construction. Hammers and nails are
adequate for installation; no special tools or fasteners are required. With
such an utterly familiar material and· attachment method, the installation
procedure is quite clear and learned quickly by on-site labor.
Since wood is easily shaped and cut, receives fasteners with ease, and
anchors with substantial holding power, only low-cost capital equipment is
needed for assembly steps in the factory. For instance, all fastening in
this method is accomplished with a stapling gun and screwdriver.
Wood surfaces are not adequate substrates for silicone adhesive/sealants,
and must be modified by priming or cladding with a suitable substrate material.
11 Wet 11 me~hods and materials {plaster., masonry, and concrete) have all but
disappeared from manufactured housing product assembly and installation routines
for obvious reasons. Therefore, a decision to clad the wooden rails with the
3-19
-
same metal tape as the vertical members rather than costing with a liquid
priming agent is a justifiable step in the right direction, despite higher
material costs than paint. Furthermore, the same spirit of easy wood
construction extends to the tape which can be readily cut with household
scissors (yet has extremely high tensile strength). Once attached to the
i,,.
wood rail (periodically stapled), it provides an excellent surface for adhesion
to the silicone.
The cladding also provides an opportunity for improved joint design that
the aluminum and steel methods cannot achieve as readily and inexpensively.· ·--· ····•· ...
The substrate cladding can offer an additional cushioning layer that can help
relieve localized stresses and dimensional variations in the framing system
and also uniformly distribute loads caused by snow or wind uplift.
The preferable method retains the "flexible fin 11 concept introduced by
BHKRA in the first phase of the Integrated Array program and is depicted in
Figure 1. Whereas the vertical metal tapes are affixed to the rails in their
11 crowned 11 position, the same tape material clads the wooden rail in its
inverted "trough" position, with its. surface rising away from the stapled
center to a height of approximately l/8 11 - 5/32 11 from the surface of the wood.
This configuration may prove ideal for supporting the glass module while not
completely deflecting the fin to 11 hard 11 bearing at the wood surface.
A simple test has shown that the fin will require a uniformly distributed
load of as much as 12 pounds per linear foot to flatten it. Since each module
(with the two-sided support) has approximately 8 feet of perimeter bearing,
a downward pressure of 96# is required for dull deflection. Given a module
weight of approximately 3.864#/ft. 2, a 35# module yields 61 total pounds or
6.8#/ft. 2 of "spring" for handling wind and snow loads before flattening to
"hard" bearing (on resilient spacers). This spring action may stiffen
3-20
I I I I I I I I I I I I I I I I I I I
-
.-
considerably beyond 10#/ft2 when the silicone infill ties the interior joint
surfaces together. The resilience of the spacer at the edge of the module
is a third actor in the cushioning system. Thus, the flexibility or resilience
of 1) the fin, 2) the silicone, and 3) the edge spacer provide a pillow against
thermal expansion, wind and snow loads,-and out-of-plane deviations along the
rail length. As further experiments proceed, it may be shown that the resilient
spacers are redundant and·may be eliminated because the crowned tape still per-
mits adequate free volume between it and the glass it supports. In other words,
it may improve the strength of the joint.by reducing the volume of sealant
needed, thus improving its contact surface-to-surface ratio.
The aluminum method simply· substitutes .rectangular aluminum tubes for the
wooden rails previously discussed. One-and-one-h~lf by two-inch tubular sec-
tions can be purchased off the shelf for incorporation into the support frame.
An automated assembly.process can be created simiJar to the wood method, but
a few extra machine steps are required for fabrication. For instance, the
aluminum channel should be slotted on the top and bottom to receive both a
field anchor and a resilient stop f~r temporarily supporting glass modules.
If the modules are supplied with resilient spacers on the· back edges, there is
no need for cladding with flexible metal tape as in the wood method for pur-
poses of creating a suitable adhesion surface. The anodized aluminum surface
is well suited to receive the silicone. If weight is a critical factor, a
drawn aluminum tube with a 0.047 inch thin wall can -be chosen, as its weight
is only 0.324 pounds per foot, approximately half that of·the wood. However,
drawn tube costs approximately $5.00 per pound or $1.64 per foot. Extruded
aluminum tubing can be purchased for approximately $1.30 per pound, but can
only be extruded in thicker will dimensions. A suitable. extruded tube for
this application would be one with a 0.125 inch wall thickness but would weigh
3-21
-
0.975 pounds per foot and, therefore, close to $1.30 per foot, more than double
the cost of wood and somewhat heavier. Given these figures, wood still remains
the first choice.
Rolled steel sections can substitute for the wood rails in certain
applications but retain some of the disadvantages of aluminium. Holes for
connections must be stamped or drilled and weight may be a problem, depending
on the wall thickness chosen. Twenty-gauge material is adequate for this
application, but may weigh as much as 0.9 pounds per linear foot, again
somewhat higher than the weight of the wood rails. It may be purchased,
however, for as low as $0.35 a foot. Thinner gauges may be used but the shape
of the section becomes more critical to reduce the possibility of damage by
the tread of workmen. Given all these factors, it still appears that wood
is the best material available for testing the concept. However, under certain
market conditions and certain applications, the use of steel or aluminium may
prove to be useful.
3-22
I I 1·
I I 11
I I I I I I I I I I I I I
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3.5 ARRAY ~ARDWARE FABRICATION
Array hardware fabrication trade-offs were investigated for an annual cell
~ production rate .of 50000 m2 area at peak power. Average system size assumed was 5 kWp using the reference module described in the module design and produc-
tion sections. The fabrication operating schedules were assumed to be 2001 a working hours, based on one eight-hour shift per day for five days p~r week throughout the year. Nine holidays and a one-week plant shutdown were also
a assumed. The BHKRA fabrication sequence is described in the following discussion. Shop fabrication of the mounting grid consists of several steps. First,
the wood stock and vane members are cut to required lengths. End-unit wiring
harnesses are assembled with their wood supports. Next, the vane members for
cladding the horizontal members are stapled to the cedar rails every 2".
[] Resilient mechanical stops are installed at fifth points of a module length on
u
the clad assembly. Then the grid of clad rails and perpendicular vanes is
assembled. The grid is then bundled and· packaged.
The use of these shelf-ready products a.nd· simple methods can forego engi-
neering on a new rolled or composite rail section and the coordination with
material suppliers and assemblers that prototype development entails, while
still retaining the general features of the original "flexible fin" concept.
The elegance· of the system is thus extended because the proof-of-concept can be
demonstrated in the BHKRA or JPL shop. Besides the materials lists of modules,
wood rails, metal tape, staples, nails, silicone adhesive, and flashing, only
the following equipment is needed to assemble and install the support frame and
modules at bench scale.
3-23
-
--
I ~
I 1. Scissors 10. Chalk line
2. Hand saw 11. Tape measure 1· 3. Stapling g·un 12. Wooden shims
I 4. Hammer and holster 13. Utility knife 5. Twine for tying bundle 14. Caulking gun I 6. Nail apron 15. Penci 1 7. Metal break for flashing 16. Gloves I 8. Tin snips 17. Tools related to electrical wiring
I 9. Ladder (depending of mock-up)
on height 18. Paper towels for clean-up
A fabricated support frame module is illustrated in Figure 3-9. Components
shown include the clad horizontal rails and the metal vanes. As indicated in
the figure, the module is not symmetrical. When two framing modules are placed
together t9 form an array, one the mirror of the other, the adjacent half-module-
width ends provide support for a single photovoltaic module.
A review of the fabrication labor and material assumptions was conducted by
JPL for an earlier iteration of the support frame design concept. Assembly time
I I I I I I
estimates from this review are shown in Figure 3-10. Material cost estimates are
shown in Ta-bles 3-5 and 3-6. Composite fabrication costs are summarized in I Figure 3-11 •
Use of larger modules in the current concept have reduced the time and
material requirements below those indicated.
3-24
I I I I I
-
~ -,___ ________ :__ _____________________ --.
ITT u fi u lf!l ILi1
lfITT ~
1¥11 ~
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f lJO!I FE/Jt'E 110/JUl.e .JIJU ff ·•1:1•
FIGURE 3-9 SNOW FENCE MODULE
3-25
;
-
w I
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°'
FIGURE 3-10 FABRICATION REQUIREMENTS
Horizontal Rafl/Vane Assembly Flashing:
4.00 minutes each x 9 units/bundle • 36.00 minutes 36.00 minutes x 1.20 (efficiency factor) • 43.20 minutes 43.20 minutes/bundle x 2 bundles • 86.20 minutes/array
2.50 (clock) m1nutes/unit x 6 unfts/bundle x 2 bundles• ~O minutes/array
Set slat · 1.00 min. Kitting/Grating/Shipping Set tape .so Staple each end 1.00 6.50 (clock) minutes/bundle x 2 bundles • 13.00 (clock) mfnutes/ar~ay
Asse~bly:
Staple (6") • 35 Staples@ 2 sec. 1.17 remove & stack ......:l! Sub-Total 4.00 minutes
. ___!! slats TOTAL 36.00 minutes
1.20 Eff. Factor 43.20 minutes
Shipping: Truckloading
Miscellaneous: Move Time:
Incoming materials Transfer Rail/Vane item to Bundle Assembly Area Set coils (Vane material) 1n place (Rail Vane) Set coils (Vane material) tn place (Array Area). Transfer crated bundles to shipping dock (stack, etc.) Other· Flashing· bundles to crating area, etc.
TOTAL MISC. TIME ROUHO-OFF
16.50 mfnutes x 1.20 (efficiency factor) • 19.80 (clock) minutes/bundle 19.80 minutes/bundle x 2 bundles • 39.60 (clock) minutes/array
.set 9 Slats Anchor 2 vanes Staple 1st slat Index ~ position® Staple© Index-Sta pl e@thru® Tie Twine Roll bundle & tie Sto.ck-stove
Sub·-Total
TOTAL
1.00 min. 1.50 1.00
: ;~1.2s min. 1.2s x 1 • a. 1s .so
1.50 -1.:.filL 16.50 minutes __!Lmtnutes 33.00 minutes !Ll.. Eff. Factor 39.60 r.iinutes
Ratio: Rail-Vane Assembly to Bundle Assembly
86.20 minutes+ 39.60 minutes• 2.177 Round-off 2.177 • 2.2
SUMl'aARY:
Ratio Rail-Vane Assembly to Bundle Assembly • 2.2 to 1 Round-off Bundle Assembly 39.60 minutes to 40 minutes Rail-Vane Assembly tfme to Bundle Assembly Assembly Time:(@ 2.2 to 1 ratfo)
88 minutes Rail-Vane Assembly
I RATIO
Rail-Vane Assembly SB mfnutes 220
Array-Assembly 40 minutes unity
Flashing 30 minutes 75
Kitting, etc. 13 minutes 32.5
Miscellaneous 9 rni nutes 22.s
6.00
· 11.00 2.00
.75 1.50 2.00
.1.2Q_ 20. 75 mf n/a rray 21.00 minutes
40 minutes Bundle Assembli (118 (lgBJ RIii liiiil .. !MIii - 11111 la.J lllilJ ... . (1111 !Mil 7• llliJ llliiJ llllil tliil1 all {iiiiiJ
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.-
WT/UNIT IUIAL MATERIAL MATERIAL LABOR
ITEM QTY WEIGHT ~OST/UNI1 COST COST
Bundle
(horiz) .55/Ft. :i,~.I~ X ~
Wood Rail 9 7.54 ea 67.86 82.17
Metal Vane 9 .315 ea 2.84 .09/Ft. 13.41 1.b1S ea
Fab Vane to Rail 9 15.12
Vane (Vertical) 4~ .342 ea 1.54 .09/Ft 7.29
Assembly (80 min.) 28.00 ,,
Wood Rail (Vertical) 1 8.19 ea 8.19 .55/Ft. 9.90
Package 1 3.25 3.25 2.10
Staples .25 1.00 o mlrL xa
Resilient Stops* 64 .0088 .56 .04 2.56 i:: 40 min.
TOTALS 81.24 118.58 60.04
Factory (manufacturing) costs calculated at a $21.00 per hour shop rate • .. Hard rubber bumper~" dia. %• high 1/8 ctr. hole@ $2.62/c
Note: Bumper diameter must be 3/8" to m~tch 3/8" gap between modules suggest 114 Fill ister HD screw-no bumper · ·
(j) Tooling Reqd.
TABLE 3-5 SNOW FENCE FABRICATION MATERIAL
3-27
TOTAL COST
82.17 ·
13.41
15.12
7.29
28.00
9.90
5.35
1.00
14.00
176.24
-
ITEM TOTAL HATERIA MATERIAl LABOR Qn WT/UNIT WEIGHT COST/UNii COST COST Metal Flashf ng I::'\ ~
11 tt:115/ ~. Material .025 th. 103 Ft. .1335/Ft 13.°75 CWT 8.40 . 12.00 f3003-H14 al coil
4.50 wide x 9 Ft. lg.
Note: 9 Ft. section 1s
universal length. Two
sections overlapped will
satisfy the vertical and
the horizontal require-
ments
6 sections reqd per
bundle.
12 sections reqd per arr. y
TOTALS 103 13.751 $8.40 $12.00 . (j) $1~6.45/CWT-1.1645/lb x .1335 lb/Ft• $.1555/Lfn. Ft.
(i) Shear to length .75 min.
Form 4 · 1.00 infn.
Form 11p
Stack/Stove
.SO mfn.
.25 mfn.
x 2 min.• 5.00 mfn (forming hem identical)
5.00 minutes 9 $.40 minute 2.00/unft
TOTAL COST
t,n 4n ·
$20.40
$2.00/unft x 6 units• $12.00/set (1 set reqd per bundle - 2 bund]es reqd per array)
NOTE: Shop Rate f $24.00/ffour
TABLE 3-6 SNOW FENCE FABRICATION MATERIAL
3-28
I
1·
I I I I I I I I I I I I I I I
-
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l]
a jfil .. ,'':· .. ·,,.·::.':·,·.1 .··':··. °lJ f11 [.ill
-~
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Time requirements (clock hours) for 1100 units/year (22 unlts/w'eek)
Rail-Vane Assembly Array Assembly Flashing Kitting-crating Miscellaneous Shipping
32.27 14.67 11.00 convert lo
manhour
64 .. 54 - 65 .. 00 29.34 - 29.50 22.00 - 22 .. 00
4.76 7.70 2.20
72.oO
9.52 - 9.50 15.40 - 15.50 4.40 - 4.50
1~
Materials: 2 x·lJi Horiz. Rails 161i Ft lg - 18 reqd • 297 lin. Ft 2 x l)s Vert. Rails 18 Ft Cg - 2 reqd • 36 11n. Ft
Total 2 x 1Ji wood rail . ffi 1 fn. Ft./Array X 1°.085 arrays · 361,305 11n. 'Ft::
. Total Annual Qty
Breakdown by item Horlz. Rails 18 x 1,085 • 19,530 pcs. • 322,245 Ft. Vert. Rails 2 x 1,085 • 2,170 pcs. • 39 8060 Ft.
w/spares • Horfz. 20,000 pcs 380,000 361,305 w/spares • Vert. 2,250 pcs 40,500
370,500
Metal Strf ps: 2• x 3/16 rtse x 35 ga (.0075) x 16.50 Ft. x 19.530 pcs • 322,245 Ft.
• • • x 17.95 Ft. x 9.765 pcs • 175,282 Ft. TOTAL 497,527 Ft.
Venetian Bltnd Mfrs.
Array Costs:
Labor (160 manhours x $21.00/hour + 22 arrays) Carton 3.25 Wood 82.17 + 9.90 • 92.07 Vanes 13.41 ~ 7 .29 • 20. 70 Staples 1.00 Stops 2.56 Nails 111• @I $.62/lb ~
Sub-Total 120.51 + 201 markup ~
TOTAL 144.61/Bundle x 2
Fabricated Array: Grand Total
FIGURE 3-11 SNOW FENCE FABRICATION ESTIMATES
3-29
152. 73
289.22
441.95
-
3.6 ARRAY INSTALLATION
Several factors were investigated to confirm assumptions relative to
module and hardware distribution and installation. These factors included:
, Volume, plant, labor and material requirements for
distributors/dealers to package the array subsystem;
, Crew size, skill, wage and indirect costs based on home-
builder volume;
, Construction sequence and material/hardware use and
waste based on homebuilder volume.
Since a mature market was initially assumed in this study, it followed that
PV systems would be installed by a representative cross section of all home-
builders and occur in a representative cross section of all homes built. The
distribution of builders and units by number of annual units is shown in
Figure 3-12.
More than two-thirds of all units are built by builders with an annual
volume of greater than 100 units. These builders, unlike those who construct
at lower volumes, subcontract all tasks. In addition, their volume of
purchases enables in-house operation of material distributorships and dealer-. ships at minimum mark-up. Array installation by large homebuilders is assumed.
For this study it is expected that a total of 165-185, 5 kWp systems are
installed at 10000 m2 annual cell production;. 825-925 systems at 50000 m2;
and, 8250-9250 systems at 500000 m2. Illustrations of the typical array
plan and wiring diagram for the 5 kWp system are shown in Figure 3-13.
3-30
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.No. of Single Family Units Built Per Builder Per .Year .
I I I I
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I t I I I 10 .11-25 26-50 51-100 101-500
-·No.' ·of Single· Family Units Built Per Builder Per Year·
:,
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FIGURE 3-13 ARRAY WIRING PLAN
! + £ ~ .! ~
' r7 t ~-. 't~ _,.,.
- I..&.. -1..a.
+- + - +-
- + - ... - + + - + - ... -
ARJrAY WI/UNd 0/AdRAtl
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A maximum of two glaziers and two laborers are necessary to install this
5 KW array. It is assumed that the installation is subcontracted to a PV
array installer and the crew arrives at the building site with 64 modules,
~ two packages containing the mounting frame, approximately 4 gallons of
adhesive/sealant, flashing, nails, and miscellaneous tools and equipment
required to complete the job in one day.
The south facing roof surface to receive the array is the approximate
size of the PV array, has one layer of 30# felt, and is free of debris. One
2 x 2 blocking member the entire length of the roof has been set at the ridge
by the General Contractor to receive the ridge vent. This member acts as a
guide against which the top rail of the mounting frame is set.
Two ladders are raised at convenient points at the eaves. While the
mounting frame packages are being unloaded by the two laborers, the crew
leader and the other glazier mount the roof to check its overall dimensions,
squareness, and evenness. If the 2 x 2 blocking is out of square, the error
is corrected .with a new beginning line snapped with a chalk line. Lack of
squareness can also be corrected with the side rail placement that is set at
the extreme slant edge of the roof. rletails are shown in figure 3-14.
3.6.1. Mo~nting Frame and Flashing Installation
Satisfied that the roof surface can receive the array, the first side
rail is called and nailed in place, square with the ridge. The first frame
bundle is then called by the crew leader. This bundle, approximately 16'
long and still packaged (but already opened to retrieve its side rail) is
carried to the roof by the two laborers on two ladders where it is received
by the two glaziers. It is carried to the ridge with the .help of the laborers,
unpackaged, and the carton thrown to the ground. Once unpackaged and positioned,
3-33
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-
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HIIDUI.£ -------JlllflJJf_ Jd/JJT
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tlJ/Yf /JTIIIIJA L f.ldf
f.('t 1·11110 l,lltK/J/( '/t. !£ YlldlP fl/lJrJII'
l'/PDO--~~~~ /AS(JA
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the top rail is placed against the 2 x 2 or chalk line by the crew leader and
other glazier who tack it in place from kneeling positions immediately across
the ridge on the north face. Concurrently, the two laborers support the
bundle on the downside to prevent its uncoiling. Once the top rail is secure,
the laborers allow the bundle to slowly uncoil, proceeding down the slope of
the roof toward the eaves and their ladders. To facilitate this routine,
hemp twine may be unrolled into the bundle at the factory to allow the glaziers
a hand in letting the bundle down the roof. When the bundle is nearly rolled
out, the laborers take positio~s on the ladders at the eave. With supervision
from the crew leader and glazier, who are now near the eaves on the free side
of the slope, the laborers square the last rail against the roof edge and
eave. A slight tug on the last rail will fully extend the frame to take out
any slack. Once squared and fully extended, the last rail is tacked in place
sufficiently to be used as a typical roof "kicker." This "positioning and
tacking" routine may involve the repositioning of the ladders to ensure
squareness and full extension without slack. One ladder may be positioned
against the gable end of the house for sighting along the rails and guaranteeing
tight fit of the horizontal rails against the side rail. The horizontal rails
are then nailed in place at their ends near the side rail and at the first
set of rail/tape intersections proceeding from the bottom rail to the top.
Once these nails are in, the secure rail ends act as a ladder for easy traveling
up and down the slant edge of the road. (see Figures 3-15, 3-16 and 3-17).
The next procedure is a quality control routine to ensure planar trueness
of the mounting frame. Two strings are tightly stretched along the full
diagonal lengths of the frame to form a large 11 X11 • Inspection along the
strings will determine the need for shimming with typical .wood shims {used
at all construction sites). Since inspection for trueness probably will
3-35
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8orro11-------~-----,."'' ---y,~r11111J .Ill AlVH-----"""
·ll!tkllll FLJJ/1//JI
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involve a need to be "inside" the frame as well as along its perimeter, a
11 path 11 up through the middle of the array should be created starting with a
tack (nail head not fully driven) in the middle of the bottom rail and
proceeding with tacks up to the top rail. Again, the tacked-in rails double
as kickers typical in any roofing installation in the 6 & 12 to 12 & 12
range. This is known as "nailing yourself in" and is always practiced during
the placement of roofing felts on steeper roofs. The first few roofing nails
are driven vertica11y along the width of the horizontally rolled-out felt
rather than all along the top edge. If not, the felt may tear underneath the
roofer's feet, especially in hot weather, causing him to disappear below the
eaves. In the fastening of the mounting frame, this routine is not so much
a matter of safety (the felts are already nailed) but one of quality control.
If a workman slipped down against a free rail, it would prevent a fall but
may damage a rail/tape joint. Tacking in the middle of the array is quite
acceptable during the correction out-of-plane depressions. If a rail needs
to be slightly raised, it can be pryed and then a shim slipped underneath
before the nail is driven home. Sue~ routines are practiced as a matter of
course in construction and point to the benefit and ease of working with wood.
After the frame has been trued to a plane with shims, if necessary, the frame
is "nailed up" from bottom to top to complete its installation. The second
bundle for the second half of the roof is then installed with the same
procedures taking care to end match the rails in the middle of the roof.
The benefits of the nailed-down horizontal rails over entire roof is
obvious. Since traffic up and down a roof surface can be considerable, such
footing for the workman will improve safety and speed installation. Traffic
laterally across the roof is less safe because of the metal tape running over
top to complete its installation. The second bundle for the second half of
3-38
I I
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lltlfdlJE JIIUT---N4RIZONTAL l'llTAI.--TAPl
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-
the roof is then installed with the same procedures taking care to end match
the rails in the middle of the roof.
The benefits of the nailed-down horizontal rails over the entire roof is
obvious. Since traffic up and down a roof surface can be considerable, such
footing for the workman will improve safety and speed installation. Traffic
laterally across the roof is less safe because of the metal tape running over
top the rails. In this regard, the crew leader should restrict lateral
traffic to the minimum required.
The next installation routine is the placement of flashing. The first
place is nailed to the bottom rail. The side rails are covered next, then
the top rail. The nails are driven along lines that will be covered by the
silicone adhesive/sealant. The mounting frame is now ready to receive the
modules.
3.6.2 Module Installation
First, appropriate sized holes are drilled through the roof sheathing at
the corners of the roof to allow the bus wires to lead to the power conditioner
inside the building. Then, the top horizontal row of modules to be placed
nearest the ridge are brought to the roof one at a time. Setting, positioning,
and electrical hook up is done "dry". Glue-down with adhesive/sealant follows
behind. One laborer works on the ground ("ground" laborer) and climbs the
ladder, bringing each unpackaged, unframed module to the top of the ladder
where it is received by the other laborer ( 11 roof 11 laborer) who brings it to
a glazier who "rough sets" it on the frame (against the resilient stops)
allowing hand space between it and the adjacent module to the l~ft or right.
He "quick-connects" it to the adjacent module, repositions it in its final
resting place, leaving a 3/8 11 space at the vertical joint over the vertical
3-40
I I I I I I I I I I I I I I I I I I I
-
n n n ~
. 1¥11.:.··.: \
~]
a a
--
metal tape running immediately underneath the parallel edges of the glass.
He then hits this vertical joint (#3 joint) with the caulking gun to create
the weatherseal. This joint, which receives less than 1/5 the volume of
silicone as does the major horizontals (#1 joints), will probably be best
done by the "connecting" glazier. The other glazier's main occupation is
working the·gun at the horizontal joints which receive .42 gallons with each
pass across the roof. Since only one pass is required for each horizontal
joint, the "gluing" glazier reaches across the 21 -0 11 + width of "dry mounted"
modules that have just been connected. In other words, he does not begin the
first major horizontal joint until the first modules of the second horizontal
row have been placed. During the placement of the first row, he has been
busy with the top perimeter joint (#2 joint) following behind the "connecting"
glazier.
The division of labor between the four workmen appears to be quite well
balanced in time. The least hurried of men is likely to be the second laborer
on the roof who can fill his 11 spare 11 moments supplying the gluing glazier if
necessary, or helping the "connecting:• glazier with positioning. While the
connecting glazier is executing the #3 joints, the roof laborer receives the
next module from the ground laborer.
The subsequent installation proceeds with the same repetitive routines,
eight modules to a row. During the placement of the next-to-the-last row,
the roof will become crowded and the roof laborer should descend to begin the
clean-up. The last row at the eaves is the most tedious to install and
probably will require a third ladder for greatest efficiency. It is executed
in the following manner.
With the "dry-mounting" of the last module in the next-to-the-last row,
the connecting glazier descends to the ground. Only the gluing glazier remains
3-41
-
.-
on the roof to finish the next-to-the-last #1 horizontal joint. The clean-up
man, meanwhile, places a third ladder for the gluing glazier's eventual descent.
The connecting glazier and ground laborer (who has been carrying modules most
of the afternoon) now must work closely together off two ladders. These two
ladders are placed at the corner of the roof; one at the cave, the other
immediately around the corner of the house on the gable end. The glazier
takes the gable end ladder to the top. The laborer takes the eave ladder and
brings the first module up. The glazier takes one end and the two men set the
module in place. The laborer descends, moves his ladder over four feet and
goes for the #2 module. Meanwhile, the glazier applies a #2 silicone joint
at the side rail, then descends and moves his ladder around to the eave 4'
from the end of the building and 4' away from the other ladder. While on the
ground, he may help the laborer carry up the #2 module. It is "rough set"
by both, quick connected by the glazier and then positioned by both.
The laborer descends and moves his ladder 4' over and goes for the next .
module while the glazier executes #3 vertical silicone joint. The glazier
descends, moves his ladder over 4 fe~t, by which time the laborer has arrived
with the next module. Both ascend and repeat the same routine. Presently,
the gluing glazier has finished the next-to-the-last #1 horizontal joint and
has descended. He and the clean-up man carry his ladder to the #1 dry-mounted
module and then the last major horizontal joint and the perimeter joint at the
bottom rail is begun.
When the last module has been dry mounted, the laborer finally descends
to help with clean up and the connecting glazier remains to help the gluing
glazier finish up, both successively moving their ladders from the ends toward
the middle of the last row. At this point, clean up should be nearing
completion. While the last of the silicone is placed, the glaziers descend,
3-42
I I 1·
I I I I I I I [I
I I I I I I I I
-
the guns are packed, and the ladders stowed on the truck. Final connections
to the power conditioner are by the Electrical Contractor.
Labor estimates for array installation are shown in Table 3-7. These
have been prepared using·units of manhours for flexibility in computing union
and non-union labor rates. Installation cost elements are listed in Table
3-8 for array assembly and installation; Table 3-9 for wiring and sealants and
Table 3-10 for flashing and roof sealants. Non-union labor rates are shown
for array assembly and installation.
Maintenance cost elements are listed in Table 3-11 for minor upkeep and
module replacement. Minor upkeep tasks do not include professional diagnosis
or inspection of the array on a periodic basis. The replacement costs do not
include transportation changes or module cost.
3-43
-
~-------------.1 TABLE'.3-7 5 KW PV ARRAY INSTALLATION MANHOURS
I
TASK GLAZIER GLAZIER LABORER LABORER
COORDINATION & SET-UP 1/4 1/4 3/4 3/4
ROOF CHECK 1/4 1/4
SET #1 SIDE RAIL 1/4 1/4
PREPARE MODULES & FRAME 1/4 1/4
HOIST II BUNDLE & ROLL OUT 1/4 1/4 1/4 1/4
SQUARE, TACK, SHIM, NAIL 1/2 1/2 1/2 1/2
SET 12 SIDE RAIL 1/4 1/4
PREPARE #2 BUNDLE 1/4 1/4
HOIST 12 BUNDLE & ROLL OUT 1/4· 1/4 1/4 1/4
SQUARE, TACK, SHIM, NAIL 1/2 1/2 1/2 1/2
PREPARE FLASHING 1/2 1/2
INSTALL FLASHING 1/2 1/2
SUBTOTAL 2-3/4 2-3/4 2-3/4 2-3/4
INSTALL 1ST ROW 3/4 3/4 3/4 3/4
BREAK FOR LUNCH i/2 1/2 1/2 1/2 INSTALL 2ND ROW 1/2 1/2 1/2 1/2
INSTALL 3RD ROW 1/2 1/2 1/2 1/2
INSTALL 4TH ROW 1/2 1/2 1/2 1/2
INSTALL 5TH ROW 1/2 1/2 1/2 1/2
INSTALL 6TH ROW 1/2 1/2 1/2 1/2
CLEAN UP
SUBTOTAL 4-3/4 4-3/4 4-3/4 4-3/4
TOTAL 8 ~ 8 8
-. .
TOTAL
2
1/2
1/2
1/2
1
2
1/2
1/2
1
2
1
1
11
3
2
3
2
2
2
2·
1-1/2
19
32
I I I I I I I I I I I I I I I I
..__ __________ __. I 3-44 I
-
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I
TABLE 3-8 INSTALLATION COST ELEMENTS
PRICING SHEET For Scherne No. JUIKRA•J rRtClNO SHEET For Schem~ Ho, BUKRA-3
Cost Component: ARRAY ASSEMBLY Coat Component: ARRAY INSTALLATION
Date: August 25, 1981 Date: August 25, 1981 Array Designer: Burt Hill Kosar Rittelmann A11ociate1 Array Designer: Burt Hill Kosar Rittelmann A11ociate1
COST/CREDIT QUANTITY MAT'L MAT'L LABOR LABOR TOTAL REHARXS COST/CREDIT QUANTITY MAT'L HAT'L LABOR LABOR TOTAL REHARKG ITEH UNIT COST UNIT COST INSTALLED lTEH UNIT COST UNIT COST IHSTAU.ED
COST COST COST COST
2 X 1-1/2 Mounting Wood Raih 14x18-1/2 $0.SS/ft. $142.4S 2.00 9.48 $142.45 * Hardware 2 $9.96/Hr. $109.56 $109.56 * 2 X 1--1/2 Wood Rails 2x16' $0.55/ft. 17.60 10.80 10.eo 17.60 Module
Metal Tape 328 ft. $0.05/ft. 16.40 2.so 2.50 16.40 Installation 42 $9.96/Rr. 179.28 178.28 * Staples 2,260 0.010/ .
Staple 22.60 22.60
Attach Tape 1.67 Hn. $15.00/ to Rails Hour $25.00 15.00
Set Rails .33 11rs. 15.00/ Hour 15.00 15.00
Attach 15.00 Vertical Tape .33 Hrs. Bour s.oo s.oo Package .167 Rra. 15.00
Hour 2.50 2.50
. *See Attached for Detailed Breakdown NOTE: 4 man crev 2 glazier•@ $10.99/Rr.
*See Attached Detailed Materials List 2 laborer•@$ 8.93/Rr.
TOTAL ... $246.SS TOTAL $288.84 TOTAL a>ST/K2 $ 4.44 TOTAL a>ST/H2 $ s.21
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TABLE 3-9 INSTALLATION COST ELEMENTS
PRICING SHEET
Coat Component& WIRING = Date: Auguat 25, 1981
I For Scheme No. BHKRA•l
Array J>e1igner: Burt Rill Kosar Rittelmann Aa1ociate1
COST/CREDIT QNTY KAT 1L KAT'L ITEM UNIT COST
COST
Wiring Harne11•l 6 $16.25 $97.50 Viring Harne11•2 1 7.48 7.48
ln1tallation: Barneai-1 6 Rarneu-2 1
'1'0TAL TOTAL CX>ST/K2
LABOR LABOR UNIT COST COST
$2.25 $13.50 2.00 2.00
1.80 10.80 2.50 2.50
TOTAL INSTALLED COST
$111.00 9.48
10.80 2.50
$133. 78 $ 2.41
REMARKS
Factory Assembled
PRICING SHEET For Scheme Ho. BHKRA•l
Coat Co111ponent: SEALANTS .
Date: Augu1t 25 1 1981 Array Deaigner: Burt Hill Eosar Rittelmann Aa1ociate1
COST/CREDIT QUANTITY HAT 1L KAT'L ITEM UNIT COST
COST
Slliccm GB 1200 4 Cal, $30/Cal. $120
TOTAL TOTAL C0ST/M2
LABOR ~BOR UNIT COST COST
TOTAL INSTALLED.
$120.00
$120.00 $ 2.18
REHAIUtS
Labor in Module lnatallatloa
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TABLE 3-10 INSTALLATION COST ELEMENTS
PRICING SHt:EI-_ For Scheme No. BHKRA-3 PRIClHC SHEET For Scheme Ho. BHKRA-3 _.;..;.;.;.;.;.;;.;.....;;;__ __ Cott Colllponent: FLASHING
Date: August 25, 1981 Array Deaigner: Burt Hill Xoaar Rittelmann Atsociates
Coat Component: ROOF CREDITS
Date: August 25, 1981 Array Designer: Burt Hill Kosar Rittelmann Associates
COST/CREDIT QUANTITY lTEH
MAT'L HAT'L LABOR UNIT COST
LABOR TOTAL REMARKS COST/CREDIT lTEM
QUANTITY MAT 1L UNIT COST
MAT'L COST
LABOR UNIT COST
LABOR COST
TOTAL REMARK
.024 11 AL
TOTAL
UNIT COST COST
... 39.37 ft.2 $0.92/ $36.22
Foot
TOTAL C0ST/M2
COST INSTALLED
$36.22
$0
36.22 . $ .66
Labor for Plywood ( 11 Installation thick) --Included in Felt C # Module weightf Installation Shingles (325#
veight) Tile Wood Shakes
Size Type-v/fir-;--retardant)
TOTAL TOTAL C0ST/K2
INSTALLED
6 Squares $SJ/Sq. $318.00 $35/Sq. $120.00 $528.00
$528.00 $ 9.59
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