DesignGuide 200Series. solyndra

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Design Guide - 200 Series Version 1.1

Solyndra LLC • 47488 Kato Road • Fremont CA 94538 • www.solyndra.com

English. 0920-30102-002Release Date: 2011-04-01

Visit http://www.solyndra.com for the most-current version of this document.

2 Design Guide 200 Series SolyndraLLC•47488KatoRoad•FremontCA94538•www.solyndra.com

GENERAL DISCLAIMER

The information contained in Solyndra’s instructions, guides, application notes, or any other document is advi-sory in nature only. Solyndra makes no representation or warranties that any referenced techniques or methods are necessarily safe, legal, or compliant with applicable codes and regulations. The customer must work with qualified system designers, installers and other professional personnel as required to ensure that all Solyndra photovoltaic system designs and installations are safe and in compliance with all applicable codes and regula-tions. Solyndra assumes no legal liability or responsibility for the accuracy, completeness, or usefulness of any information or processes disclosed herein. Reference herein to any particular commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by Solyndra.

WARRANTY DISCLAIMER

The warranty terms for Solyndra’s photovoltaic products are governed solely by the express terms of the Solyn-dra Limited Warranty provided to the purchaser of Solyndra products as may be transferred there under. Solyn-dra expressly disclaims any and all other express warranties and any and all implied warranties, including but not limited to those relating to the sale and/or use of Solyndra photovoltaic products, fitness for a particular purpose, merchantability or non-infringement or infringement of any intellectual property right. Solyndra may make changes to specifications, guidelines, and products at any time without notice. Purchasers or potential purchasers, designers and installers should contact their local Solyndra representative or the Solyndra website to ensure that they have and are working with the most up-to-date information and documentation relating to Solyndra’s photovoltaic products.

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Copyright(circlelogo©)SolyndraLLC2011.PrintedintheUnitedStatesofAmerica.AllRightsReserved.

UB.EN.20110319.V1-0.

Contact Information

Headquarters Regional Support Contacts

Solyndra LLC47488 Kato RoadFremont CA 94538 USAFax (+1)510-662-4877

US & Canada 877-511-8436 English [email protected]

EMEA 353 61 79 1124 DE, EN, FR, IT [email protected]

Belgium 0800 50735 English [email protected]

France 0800 942896 French, English [email protected]

Solyndra International AGLindenstrasse 166340 Baar, Switzerland

Germany 0800 0004366 German, English [email protected]

Greece 00800 3973 4547 English [email protected]

Italy 800 125604 Italian, English [email protected]

Spain 900 800566 English [email protected]

UK 0800 368-0423 English [email protected]

0920-30102-002 SolyndraConfidential DesignGuide200Series3

Contents

Chapter 1 Designing with Solyndra Panels 41.1. Code Compliance & Safety ...............................................................................................................................................41.2. Required Information ......................................................................................................................................................41.3. Design Sequence ..............................................................................................................................................................4

Chapter 2 Wiring 52.1. The Solyndra Connector System .....................................................................................................................................52.2. String Blocks .....................................................................................................................................................................72.3. String Wiring .....................................................................................................................................................................82.4. Home Run Wiring .............................................................................................................................................................92.5. Grounding ....................................................................................................................................................................... 102.6. Array Installation around Lightning Grids .................................................................................................................... 10

Chapter 3 Planning the Panel Layout 113.1. Designing for Wind .......................................................................................................................................................... 113.2.RoofZoneDefinitions .....................................................................................................................................................123.3. Placing Panels Over Roof Objects ................................................................................................................................. 163.4. Planning Layouts for Uneven Roofs .............................................................................................................................. 163.5. Estimating Energy Yield ................................................................................................................................................. 16

Chapter 4 Design in Seismic Areas 174.1. Clearance Tables for Building Site Zones B, C, D ........................................................................................................... 194.2. Clearance Tables for Building Site Zone E .....................................................................................................................204.3. A Note on Code Compliance ......................................................................................................................................... 22

Chapter 5 Solyndra Panel System 235.1. Solyndra Panels & Mounts .............................................................................................................................................235.2. Solyndra Cable Management System ...........................................................................................................................245.3. Optional Panel Mounting Components ........................................................................................................................245.4.StandardConfiguration ..................................................................................................................................................255.5. Roof Loads ......................................................................................................................................................................26

Chapter 6 Optimum Inverter Selection 296.1. Inverter Sizing ................................................................................................................................................................296.2. Summary .........................................................................................................................................................................30

Chapter 7 Solyndra CAD Toolkit 31

4 DesignGuide200Series SolyndraLLC•47488KatoRoad•FremontCA94538•www.solyndra.com

Des

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ls Chapter 1 Designing with Solyndra Panels

The purpose of this document is to provide design information for Solyndra 200 Series photovoltaic sys-tems. The target audience is system designers and engineers who are already skilled in photovoltaic system design. This guide will highlight the unique properties of the Solyndra 200 Series technology and their impact on system design, but is not intended to cover all aspects of system design.

Solyndra panels are designed to deliver optimum performance when installed over white, high reflectance roofs.

Projects that do not follow Solyndra’s design and installation guidelines may not provide the expected en-ergy yield, and will not be covered by Solyndra’s warranty.

1.1. Code Compliance & Safety

System installations should be designed by a properly-licensed professional in accordance with all applicable codes and standards. Solyndra panels are made of glass and can be broken. Hazardous voltage is present in photovoltaic cells at all times when they are exposed to any light source.

Before handling Solyndra panels, all Solyndra procedure, safety recommendations, and all local safety re-quirements applicable for working on roofs and around electrical equipment must be read and understood by all personnel. Reference to the Solyndra Installation Guide may be made for safety recommendations.

1.2. Required Information

In order for an effective design to be produced, the designer needs information about the installation site. For a preliminary design, items which are required are as follow:

•Address of site.•Roof diagram with dimensions, including height, and contour if available.•Roofing material type.•Roof slope.•Roof deck and load bearing capacity.•Height of nearby structures, if any.•Design wind speed, snow-load, and hail exposure.• Seismic requirements, if any.• Locations and dimensions of all roof obstructions.•Orientation of building.• Shading analysis.

1.3. Design Sequence

Design begins with the determination of string length using Solyndra’s Inverter and String Sizing Tool (see “2.3. String Wiring” on page 8), or other calculation methods, to achieve proper voltage match for an inverter type. Next, a rooftop layout is prepared. This will allow the most accurate determination of panel count, at which stage an energy yield forecast can be prepared.

The final step is the preparation of a complete Bill of Materials for purchase, and an installation plan, in-cluding roof loading (structural) design.


Wiring

Chapter 2 Wiring

2.1. The Solyndra Connector System

Each Solyndra panel has four connectors; two for positive and two for negative. The connectors are ar-ranged to make it possible to implement series and parallel connections between panels in an array.

The panel and its connectors are shown in Figure 1, along with the CAD tool symbol from the CAD pack-age that Solyndra offers. Refer to Chapter 7 on page 31 for detail of the CAD tool package.

Figure 1. Solyndra PV Panel and Power Connections

Male +

Male -

Female +

Female -

+ Positive Side

– Negative Side

Female +

Female -

Male -

Male -

The preferred orientation for Solyndra panels is with the modules (tubes) oriented north-south. Panels are then wired in series, as shown in Figure 2. This type of connection is commonly referred to as a string.

Figure 2. Two Panels Wired in Series

Male +

Male–

Female +

Female–

+ Positive Side

– Negative Side

Male+

Male -

Female+

Female +

+ Positive Side

– Negative Side


Wiri

ng Horizontal string connections are also possible, as shown in Figure 3. It is important when connecting panels in horizontal strings, as shown in Figure 3, that only connector pair be connected. Connecting both pairs would create a short circuit between the two panels.

Figure 3. Series Connection, End-to-End Panels

Male +

Male, –

Female, +

Female +

+ Positive Side

– Negative Side + Positive Side

– Negative Side

Female, +

Female -

Male +

Male, –

Do not connect!

Correct four-panel strings are shown in Figure 4. Notice how positive connectors are connected to negative connectors starting at the tail end of the string arrow (in green) and going towards the head of the arrow, increasing the total voltage with each panel.

Figure 4. Four-Panel Series Connections

Figure 5 shows connections between panels in a typical view from underneath the array.

Figure 5. Interpanel Connection of Positive and Negative Pigtails


Wiring

2.2. String Blocks

A string is a group of panels whose electrical connections are in series. The number of panels needed in each string depends on the inverter chosen. Strings can be connected in parallel within an array to reduce home run wiring costs. A typical 4 by 4 array is shown in Figure 6. Note the parallel connections, indicated by the red jumper symbols at the top of the array, and the blue jumper symbols at the bottom of the array.

Figure 6. A 4 by 4 String Block

Home Run Connection

Home Run Connection

Some designs use strings six panels long. An example is shown in Figure 7. Note that in Figure 6 and Figure 7 all series and parallel connections can be made using only the built-in panel connectors.


Home Run Connection

Home Run Connection

In some cases, the standard string-block arrangement may not be convenient for a roof location due to obstacles or other factors. Figure 8 shows a 24-panel horizontal string block. In this design, short jumper cables (shown in red and blue) will be required to make the parallel connections on the positive and nega-tive ends of the string block. Note that the string blocks shown in Figure 7 and Figure 8, while physically different, are electrically equivalent.


Home Run Connection

Home Run Connection

Positive JumpersNegative Jumpers


Wiri

ng 2.3. String Wiring

An inverter and string sizing tool is offered by Solyndra to assist in determining the optimum string length and the correct inverter size for the array. The tool is available in two versions, one for North American systems (up to 600V) and one for EU systems (up to 1000V). These tools are Excel spreadsheets named Inverter_and_StringSizing-200Series-EU and Inverter_and_StringSizing-200Series-NA. These tools may be obtained from Solyndra or an authorized distributor.

2.3.1. Determining String Length

The number of panels placed in series determines the system voltage. The system voltage must stay below the smallest of:• the maximum voltage rating of the inverter• the rated working voltage of the wiring• all applicable electrical codes

In the US, electrical equipment and wiring is rated for 600 volts maximum; in Europe the maximum rating can be as high as 1000 volts. Because panel voltage varies with temperature, the maximum voltage occurs when the temperature is cold and the inverter is off. Similarly, array voltage should be designed to stay above the minimum inverter tracking voltage when the temperature is hot and the array is operating at its maximum power point voltage, Vmp. Refer to the panel data sheet for specific temperature coefficients.

2.3.2. Parallel Strings

Connecting strings in parallel within the array reduces the amount of home-run wiring needed, saving time and cost. First, the series fuse size for each string block must be determined. The equation is:

Eqn 1. I 1.56 (N I )f scuse = :

Where N is the number of strings to be connected in parallel and Isc is taken from the panel data sheet. The calculated value must be rounded up to the next larger size. Values are listed in Table 1.

Table 1. Ifuse, Minimum Series Fuse Size for Multiple Strings in Parallel

Panel Power Rating 182 191 200 210 220 Watts

I5 2.33 2.34 2.35 2.36 2.37 Amps

One String 4 4 4 4 4 Amps

Two Strings 8 8 8 8 8 Amps

Three Strings 11 11 11 11 11 Amps

Four Strings 15 15 15 15 15 Amps

2.3.3. Maximum Number of Parallel Strings

The maximum number of strings which can be wired in parallel is limited by the series fuse rating of the panel. In order to determine the number of strings, the Fault Current Equation as specified by the control-ling code authority must be used. As an example, the IEC Fault Current Equation is shown in Eqn 2:

Eqn 2. I I 1.25 N 1 Ifault scfuse= + -^ h

where N is the number of strings to be connected in parallel while still keeping the maximum fault current (Ifault) less than the series fuse rating, as specified in the data sheet. This can be solved for N, the number of strings, as:

Eqn 3. N ( . II I )1 25 1

sc

fault fuse= +-


Wiring

The series fuse rating for 200 Series Panels is 24.4 Amps. Substituting this into Eqn 3 this for the fault current, and using the short-circuit current rating as specified in the data sheet, the maximum number of strings can be calculated. The results are shown in Table 2. It is permissible to have string blocks of fewer than the maximum number of strings in parallel.

Table 2. Maximum Number of Parallel Strings per Fused Home Run

Panel Power Rating 182 191 200 210 220 Watts

Isc 2.33 2.34 2.35 2.36 2.37 Amps

N, calculated 4.17 4.16 4.14 4.13 4.11 strings

N, rounded down 4 4 4 4 4 strings

2.4. Home Run WiringHome run wires from string blocks are connected in parallel inside combiner boxes. Just as each panel has four connections, each of the four corners of a string block will have a positive or negative pigtail available. Run a positive home run cable and a negative home run cable from the corners in a way that minimizes cable length. Use the Solyndra Cable Management System to keep wires organized and prevent them from dangling. It is shown in Figure 9, and it includes long and short channels, hangers and pegs, and panel-mount cable channels.

Figure 9. Cable Management System and Close-up View of Corner

The Solyndra cable management system makes it easy to efficiently route home run wiring. An example for 4 by 4 systems is shown in Figure 10; one for 6 by 4 systems is shown in Figure 11.

Figure 10. Typical Home Run Wiring - 4 by 4 String Blocks

Standard 8 x 12 (96 panels)equals 6 4x4 blocks

Double-wide (192 panels)equals 12 4x4 blocks

4x4 string block

Home run wiring

Figure 11. Typical Home Run Wiring - 6 by 4 String Blocks

Standard 8 x 12 (96 panels)equals 4 4x6 blocks

Double-wide (192 panels)equals 8 4x6 blocks

Home run wiring

4x6 string block


Wiri

ng 2.5. Grounding

Solyndra 200 Series Panels and mounts meet the requirements for IEC Protection Class II . It is not necessary to ground the array, or to ground any particular lead of the array at the inverter (unless required by code) when installing a Solyndra system. Due to the hermetic seals used in the construction of each Solyndra module, they are not susceptible to corrosion damage from voltage offsets with respect to ground.

2.6. Array Installation around Lightning Grids

Some rooftops are fitted with a lightning grid. A lightning grid is an array of wires running horizontally in both directions across a roof. Dimensions vary, but typically the wires are spaced a few meters apart, and the entire grid is carefully grounded to earth. These grids are occasionally fitted with vertical conductors called air terminals, or ‘lightning rods’.

A Solyndra system, when installed, may be placed over a lightning grid. Certain guidelines must be fol-lowed, but Solyndra panels do not impact the function of lightning systems or make the building more likely to have a lightning event.

Array Placement Guidelines with Lightning Grids1. Engineering for a photovoltaic system on roofs with lightning grids requires obtaining the S dimen-

sion required by code, either from the original designer or by re-calculating it. The S dimension is the minimum separation distance from the lightning grid required if additional precautions are not taken.

2. If panels are to be installed within distance S of the lightning grid components there are certain ap-plicable electrical code requirements. These may include a requirement to connect exposed metal com-ponents to the lightning grid and a recommendation that conductors coming into the building be protected by voltage shunt devices.

3. Solyndra 200 Series Panels and mounts are IEC certified Class II devices. They are not considered to have exposed metal parts and therefore do not have a requirement to be attached to the lightning grid, even if placed within the S distance.

4. Because Solyndra 200 Series Panels are IEC certified Class II devices, voltage shunt devices are not required, but are recommended, for building lead-ins and inverter protection. Use of such devices is a design decision that should be based on sensitivity of building use, or an inverter protection risk versus cost analysis.

5. Solyndra panels should never be placed over air terminals. Any air terminals that are under the array must be moved.

6. Modifying the lightning protection system to protect the Solyndra array is not necessary.


Planning the Panel LayoutChapter 3 Planning the Panel Layout

This chapter explains the rules for placing Solyndra 200 Series panels on a building roof. Solyndra panels are designed to be installed flat, elevated above the roof surface by Solyndra panel mounts. The open design of the Solyndra panel reduces wind effects, so they are self-ballasted against sliding and uplift. By attaching groups of panels together, mass is increased such that panel movement does not occur. A properly-assem-bled array has sufficient mass to resist movement without the need for attachment to the roof. In order to insure that high winds do not lift the panels, certain minimum clearances from building edges and other structures must be maintained. Panels shall only be placed over firmly-attached roof surfaces. Loose-laid membranes or other materials are not acceptable.

As with any rooftop solar system, the design must also meet fire, safety, and access clearance requirements, as dictated by applicable codes.

3.1. Designing for Wind

The Solyndra panel-and-mount system, when installed according to Solyndra guidelines, has been certified at wind speeds up to 130 MPH (208 KPH) in wind tunnel and outdoor studies. Wind speeds are defined as a 3-second gust measured at 10 meters, per ASCE 7-05, Figure 6.1. Wind speed-up due to local topography must be considered when establishing design wind speed. Consult ASCE 7-05, Section 6.5.7. Tornadoes have not been considered in developing this specification.

3.1.1. Physical Sub-Array Definition

For purposes of wind analysis, the term sub-array is defined as a group of panels which are physically con-nected together. The manner of electrical connection(s) is not relevant to this definition. The larger the sub-array, the greater the physical stability of the system.

3.1.2. Coefficients of Friction

Friction between the Panel Mount and the roof makes the panels resist movement. Solyndra has tested vari-ous combinations of Panel Mount materials and roof materials. The results are shown in Table 3. Pads are available from Solyndra. The designer is responsible for ensuring that proper friction assumptions are used.

Table 3. Coefficients of Static Friction (Fc) for Common Roofing Materials

Roof material Panel Mount (bare) Panel Mount with EPDM pad

Panel Mount with PVC pad

Panel Mount with TPO pad

TPO membrane 0.8 Notrecommended Notrecommended 1.2

Elastomeric coatings 1.2 1.2 Notrecommended Notrecommended

EVA membrane 1.6 Notrecommended 1.4 Notrecommended

PVC membrane 1.0 Notrecommended 0.8 Notrecommended

EPDM membrane 1.0 1.0 Notrecommended Notrecommended

Hard coatings 0.6 Notrecommended Notrecommended 0.8

‘Not recommended’ means that the combination is not chemically compatible. Care should be taken dur-ing installation on icy or dirty surfaces as these can reduce friction below measured values.


Plan

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out 3.2. Roof Zone Definitions

Wind clearance rules are defined according to corner, edge, and middle zones of the roof. Following the approach of ASCE 7-05, four roof zones have been defined:

•The minimum setback zone, a strip 5 feet (1.52 m) wide all around the rooftop perimeter. Panels are never permitted here. This zone is based on extensive wind testing and analysis.

•Zone A, a strip adjacent to the setback zone. Panels may be placed here, with conditions.•Zone B, an arc segment at each roof corner. Panels may be placed here, with conditions.•Zone C, the portion not included in A or B. Panels may be placed here, with conditions.

Slopes and ParapetsRoof zone definitions depend on both roof slope and the height of the parapet wall, if any. Roof slopes can be less than 1:10 (5.7°), or up to 2:12 (9.6°). Solyndra panels using Solyndra-supplied mounts are not permitted on roof slopes greater than 2:12 (9.6°).

Zone AZone A is defined as the area of the roof between the 5-foot (1.52 m) setback line and the line defined by Dimension A. Dimension A is defined as including the 5-foot (1.52 m) setback. This means that if the cal-culation gives a value of 5 feet (1.52 m), there is no Zone A. In other words, for rectangular buildings less that 12.5 feet (3.8 m) high, or less than 50 feet (15.2 m) wide, the 5-foot (1.52 m) setback is sufficient, and the width of Zone A is effectively zero, that is, there is no Zone A.

Determining Dimension A Step 1:Calculatetwovalues: •40%ofthebuildingheight. •10%ofthelesserofbuildinglengthorwidth. Step 2: Select the smallest of these possible dimensions. Step 3: Compare the result with 5 feet (1.52 m). Dimension A is the largest of these values.

Zone BZone B is the intersection of a the pie-shaped section at each exterior corner and Zone A. The pie-section is definedbyDimensionB,whichisaradius,fromthecornerofthebuilding,equalto100%ofthebuildingheight. The shape of Zone B is different for high and low parapet roofs. For high-parapet roofs, the inter-section of Zone A and Zone B is defined as Zone B. For low-parapet roofs, the intersection of Zone A and Zone B is a forbidden area.

Definition of Building DimensionsBuilding height is defined as the height above ground of the portion of the roof on which the array is in-stalled. For rectangular buildings, the definitions of length, width, and height are clear. If the building is non-rectangular, consult ASCE 7-05 for definitions.

Height is defined as the height, above the surrounding terrain or ground, of the portion of the roof on whichthearray is installed.Thereshouldbenosurroundingbuildings taller than150%ofroofheightwithinadistanceequalto200%ofroofheight.

The rules cited herein should be considered minimums. When more panels are connected together in an ar-ray, the array has more resistance to wind effects. Whenever possible, build arrays larger than the minimum. If a small array is being erected for evaluation purposes, place it in the center of the roof; well away from Zone A and Zone B.


Planning the Panel Layout3.2.1. Roof Zone Defintions

Zone definitions depend on roof slope, parapet height, and whether there is a roof ridge. Zone definition drawings are shown in Table4.Ahighparapetisonethatis19”(48cm)ormoreinheight.Forslopeslessthan 1:10, no distinction is made between monoslope and ridged.

Table 4. Zone Definition Drawing Key

Roof Slope High Parapet Low Parapet

Lessthan1:10(5.7°) MonoslopeorRidgedFigure12 Figure13

Between1:10and2:12(5.7°-9.6°) Monoslope

Between1:10and2:12(5.7°-9.6°) Ridged Figure14 Figure15

In each of the figures, red represents roof area in which panels may never be placed.

Figure 12. Roof Zone Definition - High Parapet; Monoslope ≤ 2:12; Ridged ≤ 1:10

Zone A

Zone C

Building Wall

Zone B

Zone B

Zone B Zone B

Zone B

Zone B

Zone

A

Zone

A

Zone A

Dimension A

Dimension B

Zone A5 ft (1.52 m) edge setback

5 ft

(1.5

2 m

) edg

e se

tbac

k

5 ft (1.52 m) edge setback

5 ft

(1.5

2 m

) edg

e se

tbac

k


Figure 13. Roof Zone Definition - Low Parapet; Monoslope ≤ 2:12; Ridged ≤ 1:10

Zone A

Zone A

Zone C

Building Wall

Zone B

Zone B

Zone B Zone B

Zone B

Zone B

Zone

A

Zone

A

Zone A

Dimension A

Dimension B


5 ft

(1.5

2 m

) edg

e se

tbac

k


5 ft

(1.5

2 m

) edg

e se

tbac

k



Plan

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the

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out Figure 14. Ridged Roof, Slope ≤2:12, High Parapet

5 ft (1.52 m) edge setback Roof Ridge

Zone A

Zone C

Zone B

Zone B

Zone

A

Zone

A

Zone A

Zone B

Zone B

Zone A

Zone C

Zone B

Zone B

Zone

A

Zone

A

Zone A

Zone B

Zone B

Dimension A

Dimension BDimension B

Dimension A’ (*)

Figure 15. Ridged Roof, Slope ≤2:12, Low Parapet5 ft (1.52 m) edge setback Roof Ridge

Zone A

Zone C

Zone B

Zone B

Zone

A

Zone

AZone

B

Zone A

Zone C

Zone B

Zone B

Zone

A

Zone

A

Zone A

Zone B

Zone B

Dimension A

Dimension BDimension B

Dimension A’ (*)

Zone B

Zone A

* Dimension A’ does not require the minimum 5-foot (1.52 m) setback.


Planning the Panel Layout3.2.2. Minimum Sub-Array Sizes

Table 5 defines the minimum sub-array sizes for roofs up to 60 feet (18.3 m) high, with slope less than 1:10. Table 6 defines the minimum sub-array sizes for roofs up to 60 feet (18.3 m) high, with slope less than 2:12.

Table 5. Minimum Sub-Array Sizes: Buildings ≤ 60 Ft (18.3 m) High, ≤1:10 Slope

Fc

(1)Wind

SpeedRoof Zone

85mph 137kph

90mph 145kph

95mph 153kph

100mph 161kph

105mph 169kph

110mph 177kph

115mph 185kph

120mph 193kph

125mph 201kph

130mph 208kph

≥0.6

A(2, 3) 4 4 9 9 16 25 25 36 49 100

B,low(4) 4 9 16 36 64 100 NA NA NA NA

B,high(4) 4 4 9 4 9 16 36 49 81 NA

C 4 4 9 9 9 16 25 25 36 49

≥0.8

A(2, 3) 4 4 4 4 9 9 9 16 25 25

B,low(4) 4 4 4 4 4 16 25 36 49 64

B,high(4) 4 4 4 4 4 9 9 16 16 25

C 4 4 4 4 9 9 9 16 16 25

≥1.0

A(2, 3) 4 4 4 4 4 9 9 9 9 16

B,low(4) 4 4 4 4 4 9 9 9 9 25

B,high(4) 4 4 4 4 4 9 9 9 9 16

C 1 1 4 4 4 9 9 9 9 16

Table 6. Minimum Sub-Array Sizes: Buildings ≤ 60 Ft (18.3 m) High, ≤2:12 Slope

Fc

(1)Wind

SpeedRoof Zone

85mph 137kph

95mph 153kph

130mph 208kph

≥0.6

A(2, 3) 54 63 NA

B,low(4) 40 63 NA

B,high(4) 40 60 108

C 18 32 98

≥0.8

A(2, 3) 12 20 45

B,low(4) 8 8 60

B,high(4) 12 27 44

C 9 12 40

≥1.0

A(2, 3) 8 8 40

B,low(4) 8 8 40

B,high(4) 8 8 15

C 8 8 24

Figure 16. Notes for Table 5 and Table 6.1. Fc is the coefficient of friction, from Table 3.2. The array must be as deep, or deeper, than it is wide,

that is, the number of panels in direction towards center of roof must equal or exceed number of panels along perimeter (see drawing at right).

3. No array can be fully inside Zone A. An array shall have at least two times as many panels in Zone C as in Zone A (see drawing at right.

4. Zone B is defined by Figure 12, Figure 13, Figure 14, or Figure 15, based on low or high parapet.

5. NA is Not Allowed.

Zone C

Building WallZone A


Not Acceptable Not Acceptable Acceptable


Plan

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out 3.3. Placing Panels Over Roof Objects

•Never place panels over objects more than 10 inches (25 cm) tall, or elevate panels to clear objects. •Any building steps or obstructions more than 10 inches (25 cm) high, such as overruns, HVAC units or

skylights, shall have a minimum clearance equal to the lesser of the obstruction’s width or twice its height.

3.4. Planning Layouts for Uneven Roofs

Panel Mounts should not be placed wholly or partially on raised areas such that the surface contact area between the mount and roof is reduced, or such that there is a large height disparity between panels. For sta-bility, it is recommended that the mounts not be placed on the peaks of a non-flat patterned roofs. It is also recommended that the roof structure’s load-bearing capability be assessed wherever the mounts are placed.

Many roofs have local ridges and valleys for drainage. Layouts should be designed such that Panel Mounts rest solidly on the roof. Figure 17 shows several placements. When peaks and valleys are present, as in (b), do not place mounts on peaks. This places excess localized pressure on the roof. Avoid valleys if possible, as the mount can affect drainage.

Figure 17. Right and Wrong Ways to Place Panels on Uneven Roofs

Acceptable Acceptable Unacceptable Avoid if possible Unacceptable

(a) (b)

Angles at Panel Joints200 Series Panel Mounts form flexible joints, and can generally be placed on any roof surface that varies less than 10 degrees from surface to surface.

Under certain circumstances it may be possible to bridge differences of roof slope up to 18 degrees provided that the following rules are adhered to:

• Panels can bridge either parallel or perpendicular to a ridge or valley, but the center axis of the panel must be within 10 inches (25 cm) of the ridge peak.

• Panels which use Snow Mounts cannot bridge perpendicularly across a ridge or valley because this may interfere with Snow Mount locations, unless additional Snow Mounts are used.

•While it is possible to bridge valleys, accessibility and local requirements to keep drainages clear may recommend against this design.

3.5. Estimating Energy Yield

When the layout is completed, Solyndra’s on-line energy yield forecast tool can be used to estimate hourly, daily, monthly, and annual energy yield. Detailed results are available on-screen, in a downloadable report, and in a downloadable Excel spreadsheet.

For instructions in the use of this tool, refer to the Energy Yield Forecast Tool User Guide. Contact a Solyndra representative to obtain access to the tool.


Design in Seism

ic AreasChapter 4 Design in Seismic Areas

A Solyndra array, properly installed on a rooftop, functions as a seismically-isolated system. It is designed to have some movement in the largest seismic events. When designing systems for seismically-active areas, clearances must be maintained around the array to allow for maximum possible displacements in a worst-case seismic event.

In order to determine the amount of clearance required, the engineer must determine the parameters listed below. Solyndra recommends that designers work with a qualified seismic engineer who is familiar with seismic conditions in the region where the array will be installed, and can determine the building period of the structure where the array will be installed.

Understanding Seismic Hazard LevelsThis chapter uses a method to determine expected earthquake-induced array displacements for locations with a varying intensity of seismic hazard. The seismic hazard at a given location can be defined by two pa-rameters: the short period Maximum Considered Earthquake (MCE*) spectral response acceleration (SS), and the 1-second MCE spectral response acceleration (S1).

The levels of seismic hazard are defined by maximum spectral response acceleration parameters. Four levels are defined: Low (Level 1), Moderate (Level 2), High (Level 3), and Very High (Level 4) seismic activity. Any site with spectral response parameters equal to or lower than the maximum values for a seismic hazard level are within that level.

The expected seismically-induced array displacements for any Solyndra installation can be determined from the seismic hazard level of the site. The spectral response parameters that define the four seismic hazard levels are shown in Table 7.

Table 7. Seismic Level Spectral Parameters

Seismic Hazard Level Seismic Hazard Description Maximum SS Maximum S1 Units

1 Low 0.533 0.210 G

2 Medium 1.500 0.600 G

3 High 2.000 0.940 G

4 VeryHigh 2.893 1.237 G

Multiple soil conditions are also considered for each of the four levels in this study by adjusting the SS and S1 values by site soil coefficients (Fa and Fv) per ASCE 7-05. Only site Classes B, C, D, and E (as defined by ASCE 7-05) are considered in this study. Site Class A is not considered as it is rarely encountered in occupied areas. The adjusted values are then used to define the MCE response spectra for each soil type considered.

* The MCE is defined as an earthquake of such intensity that there is a 2% probability that it would be exceeded in a time period of 50 years (or equivalently with a return period of 2,475 years).


Des

ign

in S

eism

ic A

reas Roof Slope.

Arrays should not be installed on roofs with slopes greater than 1:12 (4.76 degrees) in seismically-active areas

Coefficient of FrictionFor seismic purposes, the coefficient of friction is the dynamic friction between the roof surface and the chosen panel mount. Refer to Table 8 for values.

Table 8. Dynamic Coefficients of Friction for Common Roofing Materials

Roof material Panel Mount (bare) Panel Mount with EPDM pad

Panel Mount with PVC pad

Panel Mount with TPO pad

TPO membrane 0.6 1.0 Notrecommended 0.8

Elastomeric coatings 0.6 1.0 Notrecommended Notrecommended

EVA membrane 0.8 Notrecommended 1.0 Notrecommended

PVC membrane 0.6 Notrecommended Notrecommended 0.6

EPDM membrane 1.0 0.8 Notrecommended Notrecommended

Hard coatings Notrecommended 0.6 Notrecommended Notrecommended

‘Not recommended’ means that the combination is not chemically compatible. Care should be taken dur-ing installation on icy or dirty surfaces as these can reduce friction below measured values.

WiringCombiner boxes must be set back from the array a distance greater that the specified displacement. Home-run wiring must be flexible and include strain-reliefs. It must be long enough not to restrict any possible movement of the panels in a seismic event.


Design in Seism

ic Areas

Table 9. Clearance for Coefficient of Friction ≥ 0.6; Site Classes B, C, DSeismic

Hazard LevelBuilding Period

Clearance, 1/4:12 slope Clearance, 1/2:12 slope Clearance, 1:12 slopeinches cm inches cm inches cm

1

0.1 1 2.5 1 2.5 1 2.50.2 1 2.5 1 2.5 2 5.10.3 1 2.5 1 2.5 2 5.10.4 1 2.5 2 5.1 3 7.60.5 2 5.1 2 5.1 2 5.1

2

0.1 3 7.6 4 10.2 7 17.80.2 6 15.2 8 20.3 14 35.60.3 8 20.3 12 30.5 22 55.90.4 12 30.5 15 38.1 25 63.50.5 12 30.5 18 45.7 30 76.2

3

0.1 6 15.2 5 12.7 7 17.80.2 7 17.8 9 22.9 15 38.10.3 9 22.9 13 33 23 58.40.4 13 33 16 40.6 17 43.20.5 15 38.1 20 50.8 34 86.4

4

0.1 10 25.4 10 25.4 15 38.10.2 13 33 16 40.6 27 68.60.3 16 40.6 22 55.9 NotRecommended0.4 21 53.3 27 68.6 NotRecommended0.5 26 66 36 91.4 NotRecommended

4.1. Clearance Tables for Building Site Zones B, C, D

Table 10. Clearance for Coefficient of Friction ≥ 0.8; Site Classes B, C, DSeismic



1

0.1 1 2.5 1 2.5 1 2.50.2 1 2.5 1 2.5 1 2.50.3 1 2.5 1 2.5 1 2.50.4 1 2.5 1 2.5 2 5.10.5 1 2.5 1 2.5 1 2.5

2

0.1 2 5.1 3 7.6 5 12.70.2 4 10.2 6 15.2 9 22.90.3 6 15.2 8 20.8 15 38.10.4 10 25.4 12 30.5 18 45.70.5 10 25.4 14 35.6 23 58.4

3

0.1 3 7.6 4 10.2 4 10.20.2 6 15.2 7 17.8 10 25.40.3 9 22.9 10 25.4 17 43.20.4 11 27.9 13 33 20 50.80.5 12 30.5 15 38.1 25 63.5

4

0.1 8 20.3 8 20.3 9 22.90.2 11 27.9 13 33 20 50.80.3 14 35.6 17 43.2 31 78.70.4 19 48.3 23 58.4 NotRecommended0.5 22 55.9 30 76.2 NotRecommended


Des

ign

in S

eism

ic A

reas Table 11. Clearance for Coefficient of Friction ≥ 1.0; Site Classes B, C, D

Seismic Hazard Level

Building Period


1

0.1 1 2.5 1 2.5 1 2.50.2 1 2.5 1 2.5 1 2.50.3 1 2.5 1 2.5 1 2.50.4 1 2.5 1 2.5 1 2.50.5 1 2.5 1 2.5 1 2.5

2

0.1 2 5.1 2 5.1 3 7.60.2 3 7.6 4 10.2 6 15.20.3 5 12.7 7 17.8 11 27.90.4 9 22.9 10 25.4 15 38.10.5 9 22.9 12 30.5 19 48.3

3

0.1 3 7.6 3 7.6 3 7.60.2 5 12.7 6 15.2 8 20.30.3 7 17.8 8 20.3 13 330.4 10 25.4 11 27.9 16 40.60.5 10 25.4 12 30.5 19 48.3

4

0.1 6 15.2 6 15.2 7 17.80.2 10 25.4 11 27.9 16 40.60.3 13 33 15 38.1 25 63.50.4 16 40.6 20 50.8 31 78.70.5 19 48.3 24 61 NotRecommended

Table 12. Clearance for Coefficient of Friction ≥ 0.6; Site Class ESeismic



1

0.1 1 2.5 1 2.5 2 5.10.2 1 2.5 2 5.1 3 7.60.3 2 5.1 2 5.1 3 7.60.4 3 7.6 3 7.6 5 12.70.5 5 12.7 6 15.2 10 25.4

2

0.1 3 7.6 4 10.2 6 15.20.2 5 12.7 6 15.2 11 27.90.3 6 15.2 10 225 17 43.20.4 10 25.4 12 30.5 20 50.80.5 10 25.4 14 35.6 24 61

3

0.1 4 10.2 4 10.2 6 15.20.2 6 15.2 7 17.8 13 330.3 8 20.3 10 25.4 19 48.30.4 10 25.4 13 33 23 58.40.5 12 30.5 17 43.2 28 71.1

4

0.1 8 20.3 8 20.3 12 30.50.2 10 25.4 13 33 22 55.90.3 13 33 18 45.7 33 83.80.4 17 43.2 23 58.4 NotRecommended0.5 22 55.9 30 76.2 NotRecommended

4.2. Clearance Tables for Building Site Zone E


Design in Seism

ic AreasTable 13. Clearance for Coefficient of Friction ≥ 0.8; Site Class E

Seismic Hazard Level

Building Period


1

0.1 1 2.5 1 2.5 1 2.50.2 1 2.5 1 2.5 2 5.10.3 2 5.1 2 5.1 2 5.10.4 2 5.1 2 5.1 3 7.60.5 5 12.7 5 12.7 7 17.8

2

0.1 2 5.1 2 5.1 4 10.20.2 3 7.6 4 10.2 7 17.80.3 5 12.7 7 17.8 11 27.90.4 8 20.3 10 25.4 15 38.10.5 8 20.3 11 27.9 18 45.7

3

0.1 3 7.6 3 7.6 3 7.60.2 5 12.7 6 15.2 9 22.90.3 7 17.8 8 20.3 13 330.4 9 22.9 11 27.9 16 40.60.5 10 25.4 12 30.5 20 50.8

4

0.1 6 15.2 6 15.2 7 17.80.2 9 22.9 10 25.4 15 38.10.3 12 30.5 14 35.6 25 63.50.4 15 38.1 19 48.3 30 76.20.5 17 43.2 23 58.4 NotRecommended

Table 14. Clearance for Coefficient of Friction ≥ 1.0; Site Class ESeismic



1

0.1 1 2.5 1 2.5 1 2.50.2 1 2.5 1 2.5 1 2.50.3 1 2.5 1 2.5 2 5.10.4 2 5.1 2 5.1 3 7.60.5 4 10.2 4 10.2 6 15.2

2

0.1 2 5.1 2 5.1 3 7.60.2 3 7.6 3 7.6 5 12.70.3 4 10.2 5 12.7 8 20.30.4 7 17.8 8 20.3 11 27.90.5 7 17.8 9 22.9 14 35.6

3

0.1 2 5.1 2 5.1 3 7.60.2 4 10 4 10.2 6 15.20.3 6 15.2 7 17.8 10 25.40.4 8 20.3 9 22.9 12 30.50.5 8 20.3 9 22.9 14 35.6

4

0.1 4 10.2 5 12.7 5 12.70.2 8 20.3 9 22.9 12 30.50.3 11 27.9 12 30.5 20 50.80.4 14 35.6 16 40.6 24 610.5 16 40.6 19 48.3 30 76.2


Des

ign

in S

eism

ic A

reas 4.3. A Note on Code Compliance

The Solyndra system is designed to not be attached and to minimize lateral forces on the roof diaphragm as it acts as an isolation system. It is exempt from the prescribed requirements described in Section 1613 of the 2007 CBC (California Building Code) and Section 13.1.4 of ASCE 7- 05, under specific exemption for non-structural electrical components with weights of less than 400 pounds (182 Kg), mounted less than 4 feet (1.22 m) above floor level, provided that flexible connections are provided and testing has been done.

The applicable code sections are shown in Table 15 for reference.

Table 15. A Selection of Applicable Seismic Codes

2007 CBC, Section 1613 EARTHQUAKE LOADS

“1613.1Scope.Everystructureandportionthereof,includingnonstructuralcomponentsthatareperma-nentlyattachedtostructuresandtheirsupportsandattachments,shallbedesignedandconstructedtoresisttheeffectsofearthquakemotionsinaccordancewithASCE7,excludingChapter14andAppendix11A.Theseismicdesigncategoryforastructureispermittedtobedeterminedinaccordancewithsection1613orASCE7.”

ASCE 7-05, Chapter 13 SEISMIC DESIGN REQUIREMENTS FOR NONSTRUCTURAL COMPONENTS

“13.1.4Exemptions.Thefollowingnonstructuralcomponentsareexemptfromtherequirementsofthissection:

4.MechanicalandelectricalcomponentsinSeismicDesignCategoriesD,E,orF,wherethecompo-nentimportancefactor,Ip,isequalto1.0andbothofthefollowingconditionsapply:

a.Flexibleconnectionsbetweenthecomponentsandassociatedductwork,piping,andconduitareprovided,andb.Componentsaremountedat4ft(1.22m)orlessaboveafloorlevelandweigh400lb(1780N)orless.“

2007 CBC, Section 1708.5

“1708.5Seismicqualificationofmechanicalandelectricalequipment.Theregistereddesignprofessionalinresponsiblechargeshallstatetheapplicableseismicqualificationrequirementsfordesignatedseismicsystemsontheconstructiondocuments.Eachmanufacturerofdesignatedseismicsystemcomponentsshalltestoranalyzethecomponentanditsmountingsystemoranchorageandsubmitacertificateofcomplianceforreviewandacceptancebytheregistereddesignprofessionalinresponsiblechargeofthedesignofthedesignatedseismicsystemandforapprovalbythebuildingofficial.Qualificationshallbebyanactualtestonashaketable,bythree-dimensionalshocktests,byananalyticalmethodusingdynamiccharacteristicsandforces,bytheuseofexperiencedata(i.e.,historicaldatademonstratingac-ceptableseismicperformance)orbyamorerigorousanalysisprovidingforequivalentsafety.”


Solyndra Panel SystemChapter 5 Solyndra Panel System

5.1. Solyndra Panels & Mounts

The Solyndra 200 Series Panel System is a tool-less panel installation system requiring no fasteners; it sim-ply snaps together. It consists only of Panels and Panel Mounts. The 200 Series Cable Management System simplifies wiring and requires no tools for assembly.

Solyndra offers optional Snow Mounts and Load Distribution Feet (LDF). Figure 18 shows a six-panel system with Panel Mounts, optional Snow Mounts, and the Cable Management System.

Figure 18. Solyndra Panel Mount System

Panel

Panel MountSnow

Mount Cable Trough

Clip Cable Trough

Table 16 lists the standard parts in Solyndra systems.

Table 16. Panel Installation Hardware - Provided as Balance of System

Item Order Number Description

Panel SL200-XXX Solyndraphotovoltaicpanel.-XXXrepresentsthepowerrating.

PanelMount SLN-230 PanelMountforSolyndra200Seriesphotovoltaicpanel.

DustCapforMaleSolarlokConnectors 0048-30100

MaybeusedtocoverunusedSolarlokmaleconnectors.

DustCapforFemaleSolyndraConnectors 0048-30094

MaybeusedtocoverunusedSolarlokfemaleconnectors


Soly

ndra

Pan

el S

yste

m 5.2. Solyndra Cable Management System

Table 17 lists the components in the Solyndra Cable Management System. Refer to “2.2. String Blocks” on page 7 for information on routing home run cables within arrays.

Table 17. Solyndra Cable Management System

Item Order Number Illustration

LongCableChannel SLC-2TE

Usedforroutingthehome-runcablesaroundandwithinthearray.

ShortCableChannel SLC-2TN

Usedforroutingthehome-runcablesaroundandwithinthearray.

CableChannelPeg SLC-2CN

CableChannelPegsareinstalledonthesidesofthearray.TheysupporttheShortCableChannelsthatcontainthehome-runconnections.

CableChannelHanger SLC-2CE

CableChannelHangersareinstalledonthesidesofthearray.TheysupporttheLongCableChannelsthatcontainthehome-runconnections.

PanelMountCableChannel SLC-2DE

Usedincornerwiringandcertainothercases.

5.3. Optional Panel Mounting Components

Solyndra offers a Snow Mount for use in high snowfall areas. It increases the snow rating from 1200 Pascals (25 PSF) to 1850 Pascals (38.6 PSF). A Load Distribution Foot (LDF) is available for mineral wool roofs and other applications which require a more distributed load. Refer to “5.5.1. Snow Loads” on page 26 for details.

Table 18. Optional Snow Mount and Load Distribution Foot

Item Part Number Illustration

SnowMount SLM-2DS

UsedatthecenterofthePanelsiderailstoincreasethesnowloadrating.

LoadDistributionFoot SLL-340

Usedonmineral-woolorother‘soft’roofs.ThestandardPanelMountrestsontheLDF,whichallowstheLDFtotiltslightlytoaccommodateunevenroofsurfaces.

5.3.1. Determining the Required BOS Parts Quantities

The Solyndra CAD Tool has attributes that allow part counts to be extracted from designs. See “Chapter 7 Solyndra CAD Toolkit” on page 31 for details.


Solyndra Panel System5.4. Standard Configuration

A certain number of panel mounts, cable management components, and dust caps are included with each panel at no additional charge. The quantities are based on a typical 8 x 12 panel rectangular sub-array. Table 19 lists the standard ratios. Note that the exact quantities shipped will vary due to the standard packaged quantity of each component. For example, Long Cable Channels are shipped in minimum quantities of 15 per box.

The actual quantities required will depend on sub-array size and shape, and therefore will vary by project. For small or irregularly-shaped sub-arrays, additional components may be ordered separately.

Table 19. Standard Configuration BOS Component Ratios

BOS Component Order Number Units per Panel Ratio

PanelMount SLN-230 5mountsto4panels 1.25

Dustcapformaleconnectors - 1capto1panel 1

Dustcapforfemaleconnectors - 1capto1panel 1

LongCableChannel SLC-2TE 1channelto20panels 0.05

ShortCableChannel SLC-2TN 7channelsto50panels 0.14

CableChannelHanger SLC-2CE 3hangersto20panels 0.15

CableChannelPeg SLC-2CN 7clipsto25panels 0.28

PanelMountCableChannel SLC-2DE 1protectorto20panels 0.05

SnowMount SLM-2DS 0 0

LoadDistributionFoot(LDF SLL-340 0 0

Use of Non-Approved HardwareDo not substitute for Solyndra-specified parts without the express written consent of Solyndra. Use of non-Solyndra-specified parts will void the warranty. Materials used outdoors should be sunlight/UV resistant. Materials such as wire insulation and other components should be certified to withstand the temperatures to which they are exposed.

Tyco Solarlok Connector InformationTable 20 lists part numbers for Tyco Solarlok connectors for 10 AWG (5.3 mm2) wire, commonly used for home run connections. Table 21 lists part numbers for Tyco Solarlok connectors for 12 AWG (4 mm2). These should be used if it is necessary to replace a connector on a Solyndra panel.

Table 20. Tyco Solarlok Connector Part Numbers, 10 ga (5.3 mm2) Wire

Female Cable Connector Male Cable Connector

Plus Keyed Minus Keyed Plus Keyed Minus Keyed

Plus Coupler 5-1394462-5 - 1394461-7 -

Minus Coupler - 5-1394462-5 - 1394461-8

Unkeyed

Male Coupler, Neutral - - 6-1394461-3

Table 21. Tyco Solarlok Connector Part Numbers, 12 ga (4 mm2) Wire

Female Cable Connector Male Cable Connector

Plus Keyed Minus Keyed Plus Keyed Minus Keyed

Plus Coupler 1394462-3 - 1394461-3 -

Minus Coupler - 1394462-4 - 1394461-4

Unkeyed

Male Coupler, Neutral - - 6-1394461-2


Soly

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Pan

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m 5.5. Roof Loads

All roof-top photovoltaic designs should be reviewed by a qualified structural engineer. The following data should be considered as advisory only.

The roof deck may be made of any material as long as it is securely fastened, has a slope of 2:12 or less, can support the load, and provides proper friction. High-reflectivity white material is preferred; lower-reflectiv-ity roofs will reduce energy output.

Solyndra offers a Load Distribution Foot (LDF) for installation situations which must meet a local pressure loading limit.

Figure 19. Solyndra LDF with Mount on Top

Table 22. Distributed Roof Load, Standard Panel Mount and LDF Mount

Panel Wt. Panel Area Standard Mount Wt.

Distributed Load LDF Wt. Distributed Load w/ 4 LDF

31.8Kg 2.49m2 2.3Kg 13.9Kg/m2 2.05Kg 14.9Kg/m2 metric

70lbs 26.8ft2 5lbs 2.84psf 4.5lbs 3.05psf imperial

The values in Table 22 assume an average of 1.22 panel mounts per panel; correct for an 8 by 12 array. From a design viewpoint, adding an array to a roof adds 2.84 lbs/ft2 (13.9 kg/m2) of distributed load to the roof. However, in some cases the roof ’s live load allowance of 20 lbs/ft2 (100 kg/m2) may be eliminated in those areas covered by panels because it will no longer be possible to walk in areas occupied by the array.

5.5.1. Snow Loads

Solyndra 200 Series Panels have been tested per Section 10.16 of IEC 61646. They can withstand 25 pounds per square foot (122 kg/m2, or 1200 Pascals) of snow load when mounted on the standard four-corner mount system. For locations that require snow load ratings between 1200 and 1850 Pascals (25 and 38.6 PSF), two Snow Mounts mounts can be placed under the panel rails, at the mid-point. These Snow Mounts increase the rating to 38.6 pounds per square foot (189 kg/m2, or 1850 Pascals). Note that each Snow Mount is supporting two panels.


Solyndra Panel System5.5.2. Roof Mount Point Loads

Table 23. Snow Load Contact Pressure – Metric Units

Snow Load Total Weight

Pressure per Mount Pressure per Mount, with LDF

Panel Mounts at corners only

Panel Mounts + Snow Mounts



Pascals Kg/m2 Kg KPa Kg/m2 KPa Kg/m2 KPa Kg/m2 KPa Kg/m2

0 0 0 9.43 962 4.76 485 1.06 108 .563 57

300 30.6 76.0 30.1 3073 15.1 1541 3.25 331 1.66 169

690 70.4 175 57.1 5819 28.6 2914 6.10 622 3.08 315

900 91.8 228 71.6 7297 35.8 3653 7.64 779 3.85 393

1200 122 304 92.3 9409 46.2 4709 9.83 1002 4.95 505

1515 154 384Notpermitted

57.0 5817Notpermitted

6.10 622

1850 189 469 68.6 6996 7.32 747

Table 24. Snow Load Contact Pressure – Imperial Units

Snow Load Total Weight

Pressure per Mount Pressure per Mount, with LDF





psf psi lbs psf psi psf psi psf psi psf psi

0 0 0 197 1.36 99.1 0.688 22.0 0.153 11.7 0.081

6.27 0.044 168 629 4.37 315 2.19 67.8 0.471 34.6 0.240

14.4 0.100 385 1191 8.27 597 4.14 127 0.885 64.4 0.447

18.8 0.131 503 1494 10.4 748 5.19 159 1.11 80.4 0.559

25.1 0.174 670 1927 13.4 964 6.70 205 1.43 103 0.718

31.6 0.220 846Notpermitted

1191 8.27Notpermitted

127 0.885

38.6 0.268 1006 1433 9.95 153 1.06

Snow Loads for Mineral Wool Insulated RoofsMineral wool insulated roofs have a maximum pressure rating in order to insure that the material is not crushed. When installing with the LDF on a mineral wool insulated roof, determine the pressure rating of the insulation. Table 25 shows the maximum snow loads for Rockwool roofs in good condition, and other lesser mineral wools.

Table 25. Maximum Snow Loads on Mineral Wool Insulated Roofs

Mount Arrangement Roof TypeMaximum Snow Load

Pascals Kg/m psf psi

Panel Mounts with LDF Rockwool 1200 122 25.1 0.174

Lesser Mineral Wools 650 66.3 13.5 0.094

Panel Mounts + Snow Mounts. all with LDF

Rockwool 1850 189 38.6 0.268

Lesser Mineral Wools 1500 153 31.3 0.218


Soly

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Solyndra panel hail specifications are shown in Table 26. When planning installations, check historical weather data to determine the possibility of receiving hail in excess of the panel’s hail specification.

Table 26. Hail Specification

Specification Size Mass Velocity

Hail 25mm 7.53g 23m/s

5.5.4. Construction Materials Placement

In addition to combined loads, the roof must withstand live loads during installation. Solyndra panels are packed horizontally onto pallets for shipment. A full crate of 13 panels weighs approximately 1150 lbs (520 kg). Refer to Solyndra’s shipping documentation for exact weight and size. Have a qualified structural engineer verify that the roof structure will not be overloaded from the combination of live loads and pallets on the roof.


Optim

um Inverter Selection

Chapter 6 Optimum Inverter Selection

An inverter never needs to be rated at the same Wp as the array. Figure 20 shows how the power output varies over the course of the year, from the best (summer) days to the worst (winter) days. The hour-by-hour variation in power output over the year can be plotted as a histogram, showing the number of hours in each year which reach a given power level. The histogram shows that only on a few days of the year is the output power close to the Wp value; on most days it is significantly less. This is especially true at more northern latitudes.

Figure 20. Annual Power Output Variation & Histogram

6 AM 9 AM Noon 3 PM 6 PM

100

80

60

40

20

0

Panel Power Output; Brightest Days

Perc

enta

ge o

f Wp

Panel Power Output; Darkest Days

Intermediate Panel Power Outputs

1

100

80

60

40

20

0

Perc

enta

ge o

f Wp

4000Hourly Data

Actual Power versus Wp RatingThe actual power produced by a panel is usually less than the Wp rated power for three reasons:

•The sun is usually not as intense as the 1000W/m2 used for measuring Wp.• Power decreases as temperature increases, and the panel is usually warmer than the 25°C temperature used

for measuring Wp. This is especially likely to be the case in the summer.•The panel is not aimed directly at the sun; that is, it is not perpendicular to the sunlight.

6.1. Inverter Sizing

A typical solar array will seldom generate the STC-rated power. The inverter can and should be smaller. The amount depends on both technical factors and economic factors.

Technical FactorsSolyndra’s energy yield forecast tool produces an hour-by-hour forecast of energy production. From this, the peak power produced by the array can be determined. An inverter sized to this value will be sufficient. As an example, a nominal 250 kW array installed in Sacramento, California will produce, for a few days around June 22nd, a maximum of 206 kW. This is the peak output, so an inverter of 210 kWp is sufficient for this array.

Economic FactorsIt may make economic sense to use an even smaller inverter than the technical factors alone suggest. Invert-ers are not harmed by being connected to an array which produces more watts than the inverter rating. The inverter simply de-tunes the array, an effect known as clipping.

In the above example, a 200 kW inverter will sacrifice only 0.2% of total energy; a 180 kW inverter will sacrifice only 3.6%. The Levelized Cost of Energy (LCOE) metric is an useful indicator of the optimum inverter size, as it accounts for both the cost benefit and the lost energy penalty. Figure 21 shows the LCOE for different inverter sizes for the nominal-250 kW example system. At the ratio of 1.45, the inverter size is 172.4 kW, for a loss of only 8.4%.


Opt

imum

Inve

rter

Sel

ectio

n Solyndra offers an Excel spreadsheet tool that will automatically import the hourly data from the energy yield model and evaluate the performance of various inverter sizes.

Figure 21. LCOE vs DC:AC Ratio & NPV vs DC:AC Ratio

1.00 1.20 1.40 1.60 1.80 2.00DC:AC Ratio

$0.256

$0.254

$0.252

$0.250

$0.248

$0.246

$0.244

$0.242

LCO

E

1.45

1.00 1.20 1.40 1.60 1.80 2.00

DC:AC Ratio

$700$600$500$400$300$200$100

$0

1.75

NPV

6.1.1. Maximizing Value for AC-Limited Incentive ApplicationsSome feed-in tariffs are tied to the AC rating of the inverter, rather than the DC output of the array. There are breakpoints in the FIT at various AC sizes. This incentive system means that the economic goal is to de-termine the most cost-effective DC array size for a given AC inverter rating. This DC-to-AC ratio is called the oversize ratio. There is an optimum oversize ratio which will maximize the net present value (NPV) of the project to the investor.

Figure 22 shows the economically-optimum oversize ratio for an array installed where there is a change in FIT rates for a 250 kW-rated inverter. At a 1.75 ratio, the array is 437.5 kWp.

A 250 kWp array at this location will yield 302 MWh of energy. By increasing the array size to 437.5 kWp, the total energy yield increases to 392 MWh. This is illustrated in Figure 22. The area in red is the energy lost; the area in green is the energy gained due to the oversize array.

Figure 22. Energy-Cost Trade-off for Oversized Array

Histogram of Hourly Energy Output

121

843

565

286

910

8613

0315

2017

3719

5421

7123

8826

0528

2230

3932

5634

7336

9039

0741

2443

41

400350300250200150100

500

kW O

utpu

t 1.2 DC:AC Ratio

Histogram of Hourly Energy Output

121

843

565

286

910

8613

0315

2017

3719

5421

7123

8826

0528

2230

3932

5634

7336

9039

0741

2443

41

400350300250200150100

500

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6.2. Summary

In all cases, it makes sense to determine the actual power output of the array, and size the inverter accord-ingly. In most cases, it will make economic sense to select an inverter somewhat smaller than the actual peak power output of the array, especially at more-northern latitudes. The precise oversize ratio will depend on the tariff regimen, actual insolation, and inverter cost. Regardless of the tariff, Solyndra’s Excel tool can be used to evaluate inverter size options. Solyndra’s Design Team can also assist in determining the optimum inverter size.


Solyndra CAD Toolkit

Chapter 7 Solyndra CAD Toolkit

The Solyndra CAD Toolkit is an AutoCAD .DWG file with blocks representing Solyndra panels and mounting system components. The blocks have been assigned attributes that make it possible to extract parts counts from a drawing. Additional files in the CAD tools folder are provided to assist with this extrac-tion process. The toolkit includes two AutoCAD .DWG files. One is based on U.S. standard units and the other is based on SI (metric) units.

LayersLayers have been assigned to drawing elements to allow the designer to control the desired level of visible detail in a drawing. The defined layers are:

SOL-PANELCONNECTIONS SOL-COMPONENTHANDLES

SOL-BLOCKDESCRIPTIONS SOL-CABLECHANNELS

SOL-SHEETOBJECTS SOL-STRINGBRANCHES

SOL-PANELMOUNTS SOL-PANELS

SOL-PROOFING SOL-ATTRIBUTES

The SOL-PROOFING layer displays colored indicators of the different panel assembly blocks. There are four color coded panels in the CAD Toolkit. This color coding provides visual cues that allow the designer to quickly verify that the correct panel and array blocks were used in creating an array design. The yellow (TL) panel is always in the upper left corner of the sub-array. The light blue (T) panel is the top row of the sub-array, excluding the upper left corner panel. The pink panel (L) is the left edge of the sub-array, exclud-ing the upper left corner panel. And the dark blue (F) panel is the remaining fill of the sub-array.

BlocksThe parts required for a Solyndra installation are drawn as blocks in the Model space. The panel block contains “handles” for attaching the other mounting system parts. The Model space also contains blocks containing pre-built sub-arrays for typical stringing configurations. These sub-array blocks have been built up from the individual parts blocks and can be used as building blocks for assembling larger arrays. Where an array section calls for a configuration not provided in the pre-built sub-arrays, the designer can build up that array section from detailed panel and parts blocks. Each block may be copied from the example already inserted in the Model space or accessed from the Insert Block menu.

Panel DetailsThe Panel Details sheet contains blocks for individual parts and single panel assemblies. Panels are drawn to scale; panel dimensions have been increased slightly to allow for typical spacing between panels when installed. Panel Mounts (feet only) are drawn to scale and positioned accurately on the panel. All other parts are symbolic representations and are not drawn to scale.

Vertical String Blocks & Horizontal String BlocksThe Vertical String Blocks sheet contains blocks of pre-built strings and sub-arrays with panels arranged in typical vertical (or horizontal) stringing configuration.


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lkit Attributes

Each individual part block has text attributes attached to it, which allow parts counts to be extracted from a drawing. The attributes assigned to each part block are as follows:

Block Name Attributes Description Default qty

PANEL_W_ANCHOR PANELS Panel 1

PANEL_MNT PANEL_MOUNT PanelMounts 1

CABLE_CHANNEL_LONG CABLE_CHANNEL_LONG Longcablechannel 1

CABLE_CHANNEL_SHORT CABLE_CHANNEL_SHORT Shortcablechannel 1

Important Note: To avoid clutter in the drawing, the attributes are set as “Invisible” and “Constant”. If the blocks are exploded, the attributes will appear in the model space, and they will no longer be attached to a block and will prevent counting of parts.

Mounting BOS Extraction (ATTEXT)The attribute extraction command, ATTEXT,* can be used to ex-tract Solyndra mounting system parts counts for a completed array layout design. After entering the ATTEXT command a dialogue box will appear. Follow these instructions to extract attributes to a comma-delimited file which can be used to get a total parts count for the Solyndra mounting system.

1. Choose Comma Delimited File. 2. Click on Select Objects, and select the portion of the drawing

for which it is desired to determine the parts count.3. If the template file field is blank, click the button and locate

SOL_BOM_NOTEPAD_TEMPLATE.TXT on the computer. (This file is in the Solyndra CAD Toolkit folder.)

4. Click the Output File button to select the location for the output text file. The default file name is the name of the drawing file. Note that in order to ensure the template file is not overwritten, name the output file differently from the template file, and click OK.

5. There is now a text file with a line for each block instance, and values for the associated attributes sepa-rated by commas.

6. Locate and change its file extension to “.csv”; open the file with Excel, select all and copy. 7. Open the Solyndra BOS summary template Excel file (“[Solyndra] bos summary template.xls”).8. Paste the copied data from the extract file into the location in the BOS summary template spreadsheet.

The spreadsheet will total the number of panels and the parts counts extracted from the drawing. The spreadsheet will also compute an average parts per panel value for each mounting system component.

9. Save and close the BOS summary template file. Note that if it is desired to keep the original for later use, the working copy must be saved to a different directory and/or file name from the master copy.

*The spelling of the attribute extraction command differs depending on the language in which AutoCAD is used.• English – ATTEXT•Czech – ATREXT•German – ATTEXT• French – ATTEXTR• Spanish – ATREXT• Italian – ESTRATT• Portuguese – EXTRATRIB•Russian – АТЭКСП


Revision History

Revision Part Number Date Notes

1.0 0920-30102-001 2010-08-10 InitialVersion

1.1 0920-30102-002 2011-04-01 UpdatedforLLC

Design Guide 200 Series SolyndraLLC•47488KatoRoad•FremontCA94538•

Solyndra Quality Policy

Solyndra provides state-of-the-art solar photovoltaic systems and expert support that meet customers’ expectations for quality, delivery, technology, and responsiveness. We are committed to continually improving the quality of our products and processes.

DesignGuide 200Series. solyndra

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