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Green Collar Careers - Solar PV Bill of Materials

The Solar Site Survey workbook includes two worksheets for Solar PV materials:

• Solar PV BOM - identifies the primary electronic materials
• Solar PV Interconnect Table - identifies cables and lengths
• Solar PV Mounting Rack - identifies the mounting and racking materials

Solar PV BOM
After you've finished the Site Survey and selected the kit you'll be using, input the specific materials included in the kit in the Solar PV BOM.  Make sure that all utility specified and/or approved material requirements are met.

Solar PV Interconnect Table
Cable Route Lengths should have been identified during the Solar Site Survey.  After you've selected the Kit and have identified the number of panels and the voltage of the panels you'll need to determine how many sets of panels will need to be wired in series (panel to panel) and how many parallel runs will need to be made to the Combiner Box.  What you'll be doing is matching the DC Voltage input requirements for the Inverter while maintaining the most effective (and safe) use of wire between the PV Panels and the Combiner Box.

First we'll make this point; the longer the run, the lower the allowable current that a wire can carry.  Due to the cost of the connectorized PV panel cables it is strongly recommended to mount the Combiner Box as close to the PV Panels as possible.  If this is on a roof top, mount the Combiner Box in the attic at the closest safe point to mount it.  If using a ground mounted rack system, mount the Combiner Box under one of the panels and protected from the weather.  Not all Combiner Boxes are Outdoor rated.  If the Combiner Box is not outdoor rated mount it inside an Outdoor rated power box panel with door available from your local building supply store.

Solar PV Mounting Rack
After you've completed the sketch for the rack & mounting system insert the materials in the Solar PV Mounting Rack BOM.
 

Solar Mounting Rack is usually erected from modular extruded aluminum channels.
End of a typical rail channel.  Note the grooves where the square channel nut fits in to adjust to the span length required to mount the solar PV panel.
Square channel nut used to slide in the channel groove.
Rail channels can be mounted with threaded rod to set positions as required.