Index

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Numerics

• 2-percent design temperature, 210
• 4-to-1 rule, 281
• 10-in-1 screwdriver, 343

A

• A (amperes), 38, 49, 114
• absorption charging, 150
• AC (alternating current). See also inverters
  • circuits, 286, 288
  • overview, 39
  • power
    • disconnecting means, 346
    • output value, 169–170
  • voltage
    • inverters, 200
    • overview, 256–257
• Acme Solar Site Evaluation Tool (ASSET), 96
• active material, 128
• adjusted open circuit voltage, 206–207
• aesthetics
  • inspection issues, 350
  • of tilt angles, 77, 93–94
• Ah (amp-hours), 53–54, 137
• AHJ (authority having jurisdiction), 20, 361
• air mass, 61, 119
• albedo radiation, 60, 62
• alternating current. See AC; inverters
• altitude, 72–73, 75
• aluminum conductors, 175
• aluminum L feet, 310–311
• American Red Cross, 279
• American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE), 210, 248
• American Wire Gauge (AWG), 248
• ammeters, 40
• amorphous silicon (aSi), 112
• ampacity, 245, 248–250, 370
• amperage specifications
  • MPPT charge controllers, 235–236
  • overview, 234–235
  • PWM charge controllers, 235
• amperes (A; amps), 38, 49, 114
• amp-hours (Ah), 53–54, 137
• amps (amperes), 38, 49, 114
• analyzing reports, 98
• angle finder, 84, 93
• annual energy consumption, 193–194
• annual energy production, 191–192
• anti-islanding, 31, 160
• arc-flash safety glasses, 343
• arrays
  • available areas for, 190–191
  • azimuth, calculating, 94–95
  • battery capacity, 236
  • building-integrated mounting, 303–304
  • cleaning, 371–372
  • configuring for maximizing energy, 368–369
  • efficiency of, 230–231
  • evaluating mounting options, 190
  • ground mounting, 300–301, 366
  • inspecting, 350–351, 372
  • matching to inverters, 196–197
  • operating temperature of, 210
  • orientation of, 79–80, 368
  • power outputs, 239
  • power values, 197–199
  • roof mounting
    • ballasted racking, 299
    • flush-to-roof racking, 296–297
    • tilt-up rack mounting, 297–299
  • sizing
    • calculating, 231–232
    • consumption and contract options, 195–196
    • contract options with utility, 194–195
    • determining annual energy consumption, 193–194
    • efficiency values, 230–231
    • overview, 193, 230
    • peak sun hours, 231
    • total available solar resource, 231
    • in utility-interactive systems, 229
  • tilt of, 93–94, 299
  • top-of-pole mounting, 302–303, 366
• Article 110.12, NEC^®, 350
• Article 110.3(B), NEC^®, 316
• Article 310.15, NEC^®, 248
• Article 690, NEC^®, 18
• ASHRAE (American Society of Heating, Refrigerating, and Air-Conditioning Engineers), 210, 248
• aSi (amorphous silicon), 112
• ASSET (Acme Solar Site Evaluation Tool), 96
• attic vents, 87
• authority having jurisdiction (AHJ), 20, 361
• AutoCAD, 273
• autoranging, 42
• auxiliary load control, 152
• average high summertime temperature, 209
• AWG (American Wire Gauge), 248
• azimuth
  • of arrays, calculating, 94–95
  • orienting arrays to, 79–80
  • overview, 73–74

B

• backed currents, 260
• backfeeding, 333
• backup loads, 216
• backup subpanel, 216
• ballasted racking system, 297–299, 309
• bare wire, 319–320
• batteries
  • capacity of
    • battery banks, 226–227
    • C rate, 137–138
    • comparing to arrays, 236
    • effects of age, 139–140
    • effects of discharge rate, 140
    • effects of temperature, 139
    • overview, 137
  • charging and discharging, 44, 130–133, 144–145, 238
  • constructing, 128–130
  • corrosion of, 132
  • cycles of, 131
  • deep-cycle, 129
  • deep-discharge, 129
  • effect of cold on, 139
  • efficiency of, 230–231
  • electrical commissioning, 338
  • monitors of, 23
  • nominal, 130
  • operating temperature of, 222
  • overview, 14, 127
  • safety, 290–291
  • specifying bank size of, 142–146
  • specifying type of, 141–142
  • terminals, 132
  • types of, 133–137
  • voltage of, 149
  • wiring of, 178
• battery banks
  • calculating required energy, 142–143
  • capacity of, 226–227
  • constructing, 130
  • days of autonomy, 144
  • equalizing flooded batteries, 357–358
  • exercising in utility-interactive systems, 356
  • number of strings, 145–146
  • overview, 12, 23
  • rate and depth of discharge, 144–145
  • secondary charging sources, 144
  • serving loads, 216–219
  • sizing, 142–146, 222–228
  • torque, 356
  • watering flooded batteries, 356–357
• battery-based inverters
  • overview, 164
  • safety, 167
  • specifying, 170–171
  • user interface, 168
  • utility-interactive, 165–166
• battery-based systems
  • commissioning, 346–347
  • configuration of, 32–33
  • labeling guidelines for, 352–353
  • overview, 16, 31–33
  • pros and cons of, 33
  • sizing, 222, 236–239
  • stand-alone, 31
  • utility-interactive, 31
• battery cells, constructing, 128–130
• Becquerel, A.E., 10
• Bing Maps, 94
• BIPV (building integrated photovoltaics), 303
• black meter lead, 45, 48
• black wire, 320
• block-type mounts, 311, 312
• bonding, 324–325
• boron, 107
• bottom-up rails, 300
• breakers
  • backfed, 333
  • with correct rating, 332
  • main, 89
  • overview, 183
  • placing inverters on, 332
• brownout situation, 31
• budgeting, 190–191
• building codes, 305
• building integrated photovoltaics (BIPV), 303
• building permits, 17
• building wiring, 177
• building-integrated mounting, 22, 303–304
• bulk charging, 149–150
• bulk voltage set-point, 150
• busbars, 89

C

• C rate, 137–138
• cable assembly, 180
• cable clips, 321–322, 364
• cable ties, 321–322
• CAD (computer-aided drafting) programs, 270
• cadmium telluride (CdTe), 112–113
• calculator, 84
• cantilever, 363
• CdTe (cadmium telluride), 112–113
• central inverters, 162
• certifications, 264–265
• CFLs (compact fluorescent light bulbs), 217
• charge controllers
  • auxiliary load control, 152
  • electrical commissioning, 338–339
  • load-control feature, 151–152
  • maximum power point tracking (MPPT)
    • overview, 153–154
    • pros and cons of, 154–155
  • overview, 15, 24, 147–148
  • pulse-width modulation
    • overview (PWM), 155–156
    • pros and cons of, 156
  • sizing in battery-based systems
    • comparing array size to battery capacity, 236
    • MPPT charge controllers, 235–236
    • overview, 232–233
    • power or amperage, 234–236
    • PWM charge controllers, 235
    • voltage, 233–234
  • specifying, 156
  • stages
    • absorption charging, 150
    • bulk charging, 149–150
    • float charging, 151
  • status meters, 152
• charge rates, 143, 236
• charge set-points, 149
• charging batteries, 44, 130–133, 238
• charging cycle, 132
• chassis, 24
• chimneys, 87
• CIGS (copper indium gallium diselinide), 113
• circuit breakers
  • backfed, 333
  • with correct rating, 332
  • main, 89
  • overview, 183
  • placing inverters on, 332
• circuit length, 254
• circuits
  • configurations of, 55–58
  • current of, 245–246
  • identification of, 244
  • inverter input, 175, 244
  • inverter output, 175, 244
  • maximum and continuous current of, 245–246
  • overview, 174–175, 259–260
  • protecting, 260
  • PV output, 174, 244
  • PV source, 244
  • safety
    • AC circuits, 288
    • disconnecting, 288–290
    • order of connection, 286–288
• city covenants, 86
• clamp meters, 40, 41
• climate conditions, 90
• clipboard, 84
• clips, 321–322
• code
  • avoiding mistakes
    • conductor ratings, 363–364
    • conductors on modules, 364
    • conduit, 364–365
    • disconnects, 365
    • flashing, 363
    • grounding equipment, 365
    • grounding systems, 366
    • labeling, 366
    • structural support, 362–363
    • working clearance, 362
  • of buildings, 305
  • overview, 20
• coefficients, 202–203
• cold batteries, 139
• color-coding wire, 319–321, 340
• combiner boxes, 316, 318–319, 325
• commercial busbars, 89
• commercial permitting
  • electrical, 271–272
  • mechanical, 270–271
  • overview, 269
• commissioning
  • electrical
    • batteries, 339
    • charge controllers, 338–339
    • conductors, 339–340
    • conduit, 340
    • disconnects, 340–341
    • inverters, 339
    • overcurrent protection devices, 341
    • PV modules, 338
  • gear for, 342–343
  • mechanical
    • footings, 337
    • racking, 337
  • overview, 19
  • process for battery-based system, 346–347
  • process for grid-direct system, 345–346
  • safety, 342
  • verifying system is working, 347–349
• Common meter label, 45, 48
• compact fluorescent light bulbs (CFLs), 217
• compass, 84, 91–92
• computer-aided drafting (CAD) programs, 270–271
• conditions of use
  • ampacity values, 248–250
  • overview, 247
  • temperature considerations, 248
• conductivity, 175
• conductors
  • ampacity of, 252
  • battery wiring, 178
  • building wiring, 177
  • copper, 175
  • current-carrying, 252
  • electrical commissioning, 339–340
  • equipment-grounding, 325–326
  • ground wiring, 178
  • grounded current-carrying, 320
  • hot current-carrying, 320
  • inspections of, 350–351
  • maximizing energy, 370
  • on modules, 364
  • neutral current-carrying, 320
  • overview, 175–176
  • PV wire, 176–177
  • ratings, 363–364
  • resistance of, 254
  • sizing calculations in drawing sets, 273–274
  • underground service entrance, 176
  • ungrounded current-carrying, 320
• conduit
  • avoiding mistakes with code, 364–365
  • electrical commissioning, 340
  • metallic, 179–180
  • nonmetallic, 180–181
  • overview, 179
  • protecting wiring with, 322
  • sizing, 257–258
• connections
  • constructing, 130
  • order of, 286–288
• construction contractors board, 90
• construction site safety
  • exposure to elements, 278
  • first-aid kits, 279
  • obstacles and protective gear, 276–277
  • tools, 278
  • working, 277
• continuity test, 47
• continuous current, 245–246
• contracts, 194–195
• copper indium gallium diselinide (CIGS), 113
• corrosion, 132
• coulombs, 38
• critical loads, 218
• cross-linked polyethylene, 176–177
• crystalline modules
  • monocrystalline, 109–111
  • multicrystalline, 111
  • voltage correction factors for, 206
• current. See also AC; DC; inverters
  • ammeters, 40
  • amps, 38
  • irradiance, 64, 348
  • measuring, 40–43
  • overview, 39
  • relating in IV curves
    • overview, 122–123
    • with varying irradiance, 124–125
    • with varying temperature, 123–124
  • specifications for PV modules, 114–115
• current-versus-voltage curve. See IV curve

D

• daisy chaining, 56
• Database of State Incentives for Renewables and Energy Efficiency (DSIRE), 28, 274
• days of autonomy, 144, 223, 226
• DC (direct current). See also inverters
  • appliances, 221
  • disconnect, 346
  • disconnecting means, 174
  • loads, 226
  • maximum voltage contribution
    • adjusted open circuit voltage, 206–207
    • NEC^® info, 205–206
    • overview, 201–202
    • temperature coefficients, 202–203
  • minimum voltage contribution
    • calculating, 211–212
    • long-term performance, 208–209
    • mounting, 210
    • number of modules needed in strings, 212–213
    • overview, 208
    • temperature, 209–210
  • overview, 24, 39
  • voltage, 254–256
  • voltage window
    • inverters, 200–201
    • overview, 169
• dead loads, 305–307
• declinations, 91–92
• deep-cycle batteries, 129, 131
• deep-discharge batteries, 129
• depth of discharge (DOD)
  • of battery banks, 224–225
  • overview, 144–145
• derate factor, 248
• diffuse radiation, 60–61
• digital camera, 84
• digital multimeter (DMM), 40, 44, 84, 343
• digital photos
  • for basic information, 86
  • for electrical information, 89–90
  • for site information, 86–87
  • for structural and mechanical information, 87–89
• diode, 107
• direct current. See DC; inverters
• direct radiation, 60–61
• discharge rates, 140
• discharging batteries
  • overview, 130–133
  • rate and depth of, 144–145
• disclaimers, 196
• disconnecting
  • circuits, 288–290
  • means, 317–318
• disconnects
  • avoiding mistakes with code, 365
  • electrical commissioning, 340–341
  • grouped, 331
  • overview, 27, 181–182
  • placing inverters on, 332
  • sizing
    • on inverter circuits, 260
    • overview, 258–259
    • on PV circuits, 259–260
  • utility-required, 330, 331
• distributed generation, 10
• distribution panels, 83
• DMM (digital multimeter), 40, 44, 84, 343
• documenting sites
  • basic information, 86
  • electrical information, 89–90
  • site information, 86–87
  • structural and mechanical information, 87–89
• DOD. See depth of discharge (DOD)
• dopants, 110–111
• doping cells, 106–107
• drawing sets
  • clarity of, 273
  • conductor-sizing calculations, 273–274
  • equipment locations, 273
  • job notes, 274
  • overview, 272–273
• DSIRE (Database of State Incentives for Renewables and Energy Efficiency), 28, 274
• dynamic values, 92

E

• earthquakes, 308–309
• eastern declination, 91–92
• edge-of-cloud effect, 62
• efficiency values, 230–231
• EGC (equipment-grounding conductor), 325–326
• electrical. See also safety
  • commissioning
    • batteries, 339
    • charge controllers, 338–339
    • conductors, 339–340
    • conduit, 340
    • disconnects, 340–341
    • inverters, 339
    • overcurrent protection devices, 341
    • PV modules, 338
  • connecting to utility
    • backfed circuit breakers, 333
    • circuit breakers with correct rating, 332
    • fastening kits, 333
    • ground fault protection integrated into overcurrent protection device, 332
    • locating protection, 333
    • panels with multiple power sources, 333
    • placing inverters on circuit breakers or disconnects, 332
    • requirements, 329–330
  • grounding
    • equipment connection, 323–326
    • overview, 323
    • sizing equipment-grounding conductors, 325–326
    • sizing system grounding, 328–329
    • system ground connection, 327–328
  • information, 89–90
  • integrating
    • combiner boxes, junction boxes, and wiring, 318–319
    • equipment locations, 316–317
    • locations for disconnecting means, 317–318
  • maintenance
    • module wiring, 354–355
    • PV cleanliness, 355
    • wiring connections, 354
  • permits, 17, 267–269, 271–272
  • wiring
    • color-coding, 319–321
    • protecting with conduit, 322
    • on PV modules, 321–322
• electrical metallic tubing (EMT), 180
• electrician, 90
• electricity
  • basics of, 54–55
  • circuit configurations
    • overview, 55
    • parallel, 57–58
    • series, 56–57
    • series-parallel, 58
  • current
    • ammeters, 40
    • amps, 38
    • direct and alternating, 39
    • measuring, 40–43
  • energy
    • amp-hours, 53–54
    • overview, 51
    • power versus, 50–51
    • watt-hours, 53
  • Ohm’s law, 49–50
  • power
    • amp-hours, 53–54
    • energy versus, 50–51
    • overview, 50
    • power equation of, 51–53
    • watt-hours, 53–54
  • resistance
    • measuring, 47–49
    • ohms, 47
  • specifications for PV modules
    • current specifications, 114–115
    • maximum power point, 116–117
    • overview, 113–114
    • power tolerance, 118
    • series fuse rating, 118
    • voltage specifications, 115–116
    • voltage temperature coefficient, 117–118
  • voltage
    • measuring, 44–46
    • nominal and operating, 43–44
    • overview, 43
• electrolyte, 129
• electromotive force, 43
• electrons, 38, 107
• EMT (electrical metallic tubing), 180
• enclosures, 316–317
• energy
  • amp-hours, 53–54
  • calculating, 142–143
  • calculating in watt-hours, 53
  • calculating output, 66–67
  • consumption of, 219–220
  • determining annual consumption, 193–194
  • maximizing, 367–372
  • overview, 51
  • power versus, 50–51
  • required during outages for utility-interactive systems, 219
• engine generators, 144
• equalization charge, 134, 357
• equinoxes, 70–72
• equipment
  • grounding, 323–326
  • location of, 316–317
  • location of in drawing sets, 273
• equipment-grounding conductor (EGC), 325–326
• error codes, 346
• expansion fittings, 340
• extension cords, 285
• extension ladder, 280
• extra heavy duty (Type IA) ladder, 280
• eye protection, 276

F

• factory-installed conductors, 176
• fall equinox, 70–72
• fall protection, 283
• fastening kits, 333
• fault situation, 290–291
• faults, 260
• feed-in tariff system (FIT), 28, 194
• fiberglass ladder, 281
• firefighter access, 87
• firmware, 163
• first-aid kit, 279
• fish tape, 322
• FIT (feed-in tariff system), 28, 194
• FLA (flooded lead-acid batteries), 133–134
• flashing
  • avoiding mistakes with code, 363
  • block-type mounts with integrated flashing, 312
  • overview, 310–311
  • post-type footings, 311–312
• flashlights, 84
• flat roofs, 297
• flexible metallic tubing (FMT), 180
• float charging, 151
• floating, 185
• flooded batteries, 23, 356–357
• flooded lead-acid batteries (FLA), 133–134
• flush-to-roof racking system, 296–297, 306
• FMT (flexible metallic tubing), 180
• footings
  • mechanical commissioning, 336–337
  • overview, 300
  • post-type, 311–312
• footwear, 277

• 4-to-1 rule, 281

• framing, 88
• fuel sources, 240
• full sun, 119
• fuses
  • ground fault protection, 345
  • overview, 183–184
• future shading, 86

G

• gauge, 339
• GE (grounding electrode), 326–327, 366
• GEC (grounding-electrode conductor), 326–327
• generators
  • engine, 144
  • incorporating in off-grid homes, 240
  • incorporating in utility-interactive systems, 239–240
  • sizing in battery-based systems, 241–242
• geotechnical engineer, 313
• GFCI (ground fault circuit interrupter), 160
• GFP. See ground fault protection (GFP)
• glasses, 42, 343
• gloves, 42, 277, 343
• goggles, 276
• Google Earth, 94
• Google SketchUp, 94
• graphs, 99
• gray wire, 320
• green wire, 319–321
• grid-direct inverters
  • large transformers and low-frequency technology, 163
  • maximum power point tracking (MPPT), 160
  • operation of, 158–159
  • overview, 25
  • power output sizes, 162
  • safety features, 159–160
  • small transformers and high-frequency technology, 163
  • specifying, 169–170
  • transformer-less technology, 163–164
  • user interface, 161
• grid-direct systems
  • commissioning, 342, 345–346
  • configuration of, 29–30
  • overview, 12, 16, 29–31
  • pros and cons of, 30–31
  • sizing
    • array, 193–196
    • budget and available array areas, 190–191
    • combining power and voltage information, 213–214
    • estimating annual energy production, 191–192
    • inverters, 196–197, 214
    • power values for arrays and inverters, 197–199
• ground busbar, 327
• ground connections, 327–328
• ground fault circuit interrupter (GFCI), 160
• ground fault protection (GFP)
  • device, 321
  • fuse, 345
  • integrated into overcurrent protection device, 332
  • overview, 184–185
• ground lugs, 324
• ground mounting, 300–301, 313–314, 337, 366
• ground plan, 271
• ground rod, 326–327, 366
• ground wiring, 178
• grounded conductors, 175
• grounding
  • avoiding mistakes with code, 366
  • equipment connection, 323–326
  • overview, 323
  • sizing equipment-grounding conductors, 325–326
  • sizing system grounding, 328–329
  • system ground connection, 327–328
• grounding clips, 324–325
• grounding electrode (GE), 326–327, 366
• grounding-electrode conductor (GEC), 326–327
• grouped disconnects, 331
• guerrilla solar, 329

H

• hard hats, 276
• heat-resistant thermoplastic (THHN), 177
• heavy duty (Type I) ladder, 280
• height, of ladder, 280
• helical piers, 314
• hetero-junction modules, 113
• high-frequency technology, 163
• high-resistance connection, 354
• high-voltage safety gloves, 343
• hiking boots, 277
• historic districts, 86
• hold-down kits, 333
• Home Power magazine, 313
• homeowners’ associations, 86
• home-run cables, 287, 345
• hydrogen, 23

I

• I symbol, 38
• IBC (International Building Code), 310, 361
• I_mp (maximum power current rating), 115, 153, 256
• impedance, 46
• inclinometer, 93
• infrared thermometer, 343
• ingot, 109–110
• inline meter, 40
• insolation (peak sun hours), 66, 231
• inspections
  • aesthetics, 350
  • conductors on arrays, 350–351
  • labeling, 351–353
  • “neat and workmanlike manner,” 350
  • overview, 349
• inspectors, 283
• insulating gloves, 42
• insulators, 107
• integrated disconnects, 90
• interconnection rules, 90
• International Building Code (IBC), 310, 361
• International System of Units (SI), 38
• Interstate Renewable Energy Council (IREC), 274
• inverters. See also battery-based inverters; grid-direct inverters; stand-alone inverters
  • AC voltage, 200
  • central, 162
  • circuits, 260
  • DC disconnect, 346
  • DC voltage window, 200–201
  • electrical commissioning, 339
  • error codes, 346
  • matching to arrays, 196–197
  • maximizing energy, 369–370
  • maximum current input, 214
  • overview, 15, 24–25, 157
  • placing on circuit breakers or disconnects, 332
  • power values for, 197–199
  • specifying, 168–171
  • stacked, 168, 237
  • string, 162
  • ungrounded, 164
• IREC (Interstate Renewable Energy Council), 274
• irradiance
  • charts, 62–63
  • current and voltage, 64
  • effects on surveying test conditions, 122
  • factors of, 62
  • IV curves, 124–125
  • measuring with a pyronometer, 64–65
  • overview, 61–62
  • sensors, 122, 343, 347
• irradiation, 13, 65–66
• I_sc (short circuit current), 114
• islanding, 159
• IV curve
  • overview, 122–123
  • with varying irradiance, 124–125
  • with varying temperature, 123–124

J

• joules, 51
• junction boxes, 318–319

K

• kilowatt (kW), 50
• kilowatt-hours (kWh), 51, 53, 192
• kilowatts per square meter (kW/m²), 61–62

L

• L (total circuit length), 256
• labeling
  • avoiding mistakes with code, 366
  • for inspections, 351–353
  • overview, 185–186
• ladders
  • overview, 84
  • selecting, 279–281
  • setting up, 281–282
• lag screws, 309–310
• latitude, 73, 74
• lead-acid batteries, 132
• lead-calcium batteries, 136
• leveling tool, 313
• LFNC (liquid-tight flexible nonmetallic conduit), 180–181
• licenses, 90, 264–265
• licensing department Web sites, 90
• light duty (Type III) ladder, 280
• lighting, 217
• lightning protection, 327–328
• line side connection, 331
• liquid-tight flexible nonmetallic conduit (LFNC), 180–181
• live loads
  • seismic loading, 308–309
  • snow loading, 308
  • wind loading, 307–308
• load centers, 26–27
• load profiles, 140
• load rating of, ladder, 280
• load side connection, 331
• load-analysis spreadsheets, 221
• load-control feature, 151–152
• loads
  • dead, 305–307
  • live, 307–309
  • overview, 25–26
  • sizing in battery-based systems
    • average daily energy consumption for stand-alone systems, 219–221
    • energy required during outages for utility-interactive systems, 219
    • overview, 216–221
    • served by battery banks, 216–219
• local building department, 86, 87
• local climate conditions, 90
• local jurisdiction, 173
• local requirements, 101
• low-frequency transformer technology, 163, 168
• low-pitch roofs, 297
• low-resistance connections, 48
• low-slope roofs, 77
• lubricant, 322
• lugs, 324

M

• magnetic declination, 79, 91–92
• magnetic variation, 91
• main distribution panel (MDP), 26, 89
• main load center, 26
• maintenance
  • batteries, 141–142
  • battery banks
    • equalizing flooded batteries, 357–358
    • exercising in utility-interactive systems, 356
    • torque, 356
    • watering flooded batteries, 356–357
  • electrical
    • module wiring, 354–355
    • PV cleanliness, 355
    • wiring connections, 354
  • mechanical, 354
  • overview, 353–354
• maintenance-free batteries, 23
• maps of peak sun hours, 67–69
• maximum current
  • circuit, 250
  • non-PV circuits, 246–247
  • PV circuits, 245–246
• maximum DC voltage contribution
  • adjusted open circuit voltage, 206–207
  • NEC^® info, 205–206
  • overview, 201–202
  • temperature coefficients, 202–203
• maximum power current rating (I_mp), 114, 153, 256
• maximum power point (MPP), 116–117, 153–154, 161
• maximum power point tracking (MPPT)
  • charge controllers, 235–236
  • overview, 153–154, 160
  • pros and cons of, 154–155
• MDP (main distribution panel), 26, 89
• mechanical commissioning
  • footings, 337
  • racking, 337
• mechanical information, 87–89
• mechanical parts. See also roof mounting
  • arrays
    • building-integrated mounting, 303–304
    • ground mounting, 300–301
    • overview, 294
    • top-of-pole mounting, 302–303
  • building codes, 305
  • dead loads, 305–307
  • live loads
    • seismic loading, 308–309
    • snow loading, 308
    • wind loading, 307–308
  • overview, 293
  • supports, 313–314
• mechanical permits, 266, 270–271
• metal roofs, 298
• metallic conduit, 179–180
• microhydroelectric systems, 144
• microinverters, 162
• micrometers, 113
• minimum DC voltage contribution
  • calculating, 211–212
  • long-term performance, 208–209
  • mounting, 210
  • number of modules needed in strings, 212–213
  • overview, 208
  • temperature, 209–210
• Minimum Design Loads for Buildings and Other Structures (ASCE 7-05), 305
• mirrors, 62
• modules (PV)
  • cells
    • construction and manufacturing, 106–107
    • creating one-way electron paths with PN junctions, 107
    • doping to create semiconductors, 106–107
    • photovoltaic effect, 108
  • connected to charge controllers, 233
  • crystalline kinds
    • monocrystalline, 109–111
    • multicrystalline, 111
  • electrical commissioning, 338
  • electrical specifications for
    • current, 114–115
    • maximum power point, 116–117
    • overview, 113–114
    • power tolerance, 118
    • series fuse rating, 118
    • voltage specifications, 115–116
    • voltage temperature coefficient, 117–118
  • equipment grounding options for, 325–326
  • interconnections, 321
  • needed in strings, 212–213
  • overview, 14, 22, 105–106
  • positioning
    • orienting arrays to azimuth, 79–80
    • tilt angles, 77–79
  • relating current and voltage in IV curves
    • overview, 122–123
    • with varying irradiance, 124–125
    • with varying temperature, 123–124
  • surveying test conditions for
    • irradiance effects on, 122
    • standard test conditions, 119–120
    • temperature effects on, 120–121

• thin film kinds
  • amorphous silicon, 112
  • cadmium telluride, 112–113
  • copper indium gallium diselinide, 113
  • overview, 111–112
  • wiring, 321–322, 354–355

• moisture and heat resistant thermoplastic (THWN-2), 177, 364
• moisture-resistant thermoset (RHW), 178
• monitoring systems, 370, 371
• monocrystalline modules, 109–111
• mounting. See also roof mounting
  • building-integrated, 22, 303–304
  • ground, 300–301, 313–314, 337, 366
  • top-down, 297
  • top-of-pole, 302–303, 313–314
• MPP (maximum power point), 116–117, 153–154, 161
• MPPT. See maximum power point tracking (MPPT)
• multicrystalline modules, 111, 206
• multimeter, 40, 44, 84, 343
• multiplicity, 161

N

• N type, 107, 108
• NABCEP (North American Board of Certified Energy Practitioners), 265, 310
• National Electrical Code® (NEC®), 20, 205–206
• National Electrical Manufacturers Association (NEMA) enclosure ratings, 317
• National Fire Protection Association Web site, 20
• National Oceanic and Atmospheric Administration (NOAA), 92
• National Renewable Energy Laboratory (NREL), 65, 67, 100

• “neat and workmanlike manner,” 350

• NEC® (National Electrical Code®), 20, 205–206
• NEMA (National Electrical Manufacturers Association) enclosure ratings, 317
• net metering, 28, 90
• neutral current-carrying conductors, 320
• nickel-cadmium batteries, 136–137
• NOAA (National Oceanic and Atmospheric Administration), 92
• nominal voltages
  • AC, 257
  • of batteries, 130
  • of battery banks, 225–226
  • overview, 43–44
• nonmetallic conduit, 180–181
• North American Board of Certified Energy Practitioners (NABCEP), 265, 310
• North Pole, 72
• Northern Hemisphere, 70–72, 91
• NREL (National Renewable Energy Laboratory), 65, 67, 100

O

• O meter label, 48
• obstructions, 87
• Occupational Safety and Health Administration (OSHA), 17, 275–276, 279
• OCPDs. See overcurrent protection devices (OCPDs)
• off-grid homes, 240
• ohms, 47
• Ohm’s law, 49–50
• one-line drawings, 267, 268, 271–272
• operating voltage, 43–44, 116
• orientation, 98
• OSHA (Occupational Safety and Health Administration), 17, 275–276, 279
• outages, 219
• outdoor installation, 317
• output circuits, 174, 244
• output voltage, 240
• output wires, 89
• overcurrent protection devices (OCPDs)
  • circuit breakers, 183
  • electrical commissioning, 341
  • fuses, 183–184
  • integrated into by ground fault protection, 332
  • overview, 27
  • sizing
    • on inverter circuits, 260
    • overview, 258–259
    • on PV circuits, 259–260
• overspanned rafters, 88

P

• P type, 107, 108
• panels, 22, 333
• panoramic views, 96
• parallel connections, 57–58, 129
• peak sun hours (insolation), 66, 231
• penetrations, sealing with flashing
  • block-type mounts with integrated flashing, 312
  • overview, 310–311
  • post-type footings, 311–312
• permitting
  • for commercial systems, 269–272
  • cost of, 264
  • drawing sets, 272–274
  • licenses and certifications, 264–265
  • overview, 17, 263–264
  • for residential systems, 265–269
• personal protective equipment (PPE), 276
• phantom loads, 217
• phosphorous, 107, 110, 111
• photons, 106, 108
• photos
  • for basic information, 86
  • for electrical information, 89–90
  • for site information, 86–87
  • for structural and mechanical information, 87–89
• photovoltaic effect, 108
• Pictometry, 94
• pipes, 174
• plan checkers, 269
• plan view, 266
• plastic ties, 322, 364
• plates, 129
• plumbing vents, 87
• PN (positive-negative) junctions, 107
• point loading, 306
• point of common connection (POCC), 27–28
• polarity, 320
• pole racks, 22
• pole-mounted arrays, 366
• positive attachment method, 308–309
• positive declination, 91–92
• positive-negative (PN) junctions, 107
• post-type footings, 311–312
• power
  • amp-hours, 53–54
  • combining with voltage information, 213–214
  • density, 109, 190
  • differences between energy and, 50–51
  • draw, calculating, 237–238
  • MPPT charge controllers, 235–236
  • outputs, 162, 239
  • overview, 50, 234–235
  • panels with multiple sources, 333
  • point trackers of, 201
  • power equation, 51–53
  • PWM charge controllers, 235
  • tolerance of, 118
  • watt-hours, calculating, 53
• power tools, 285
• power values, 195–196
• PPE (personal protective equipment), 276
• protective gear, 276–277
• pulling permits, 265
• pulse-width modulation (PWM), 155–156
• pulsing charges, 155
• PV Watts tool, 82, 192
• PV wire, 176–177
• PVC (rigid polyvinyl chloride), 180
• PWM (pulse-width modulation), 155–156
• pyronometer, 64–65

Q

• quick-connect plugs, 364

R

• racking
  • ballasted, 299
  • details, 270
  • flush-to-roof, 296–297
  • mechanical commissioning, 337
  • overview, 22
  • plans, 270
  • structures, 101
• rafters, 88, 363
• rate of discharge, 144–145
• rated maximum power point current, 351
• rated maximum power point voltage, 351
• rated power output, 116, 117
• rated values, 224
• R_c (resistance of conductors), 254
• red meter lead, 45, 48
• red wires, 319–321
• Redbook, 67
• reflectance, 60, 62
• reflective surfaces, 62
• refrigeration, 217
• remote start, 240
• reroofing, 87–88
• residential permitting
  • electrical, 267–269
  • mechanical, 266
  • overview, 265
• resistance
  • of conductors, 254
  • measuring, 47–49
  • ohms, 47
• resistance of conductors (R_c), 254
• resistance-measurement feature, 48
• restrictions, 86–87
• reverse polarity, 46
• RHW (moisture-resistant thermoset), 178
• rigid polyvinyl chloride (PVC), 180
• roof mounting
  • arrays, 337
  • ballasted racking, 299
  • building codes, 305
  • combiner boxes, 260
  • dead loads, 305–307
  • flashing, 363
  • flush-to-roof racking, 296–297
  • framing, 88
  • lag screws, 309–310
  • live loads, 307–309
  • sealing penetrations with flashing, 310–312
  • tilt-up rack mounting, 297–299
• rooftops
  • material of, 83
  • safety
    • fall protection, 283
    • maintaining walkways, 285
    • overview, 282
    • storing tools, 283–284
  • slope of, 93–94
  • tilt of, 83
  • truss, 363
• rotations per minute (RPM), 240

S

• safety
  • batteries, 290–291
  • circuits
    • AC circuits, 288
    • disconnecting, 288–290
    • order of connection, 286–288
  • commissioning, 342
  • construction site
    • exposure to elements, 278
    • first-aid kit, 279
    • obstacles and protective gear, 276–277
    • tools, 278
    • working, 277
  • devices, 15–16, 17
  • electrical
    • overview, 285
    • shock hazards, 285–286
  • features
    • of grid-direct inverters, 159–160
    • of stand-alone inverter operation, 167–168
  • glasses, 42, 343
  • gloves, 343
  • goggles, 276
  • ladders
    • selecting, 279–281
    • setting up, 281–282
  • overview, 17–18, 275–276
  • rooftops
    • fall protection, 283
    • maintaining walkways, 285
    • overview, 282
    • storing tools, 283–284
• satellite images, 85, 87, 94
• screwdrivers, 84
• sealed batteries, 23, 142, 355
• sealed lead-acid batteries, 134
• sealing with flashing
  • block-type mounts with integrated flashing, 312
  • overview, 310–311
  • post-type footings, 311–312
• seasons, 70–72
• seismic loading, 308–309
• semiconductors, 106–107
• series connections, 56–57
• series fuse rating, 118
• series string, 56–57, 118
• series-parallel connections, 58
• shading, 86, 98
• shading factor (SF), 98
• shading-analysis tools, 84, 95–97
• shock hazards, 285–286
• shoes, 277
• short circuit current (I_sc), 114
• shorting, 114
• SI (International System of Units), 38
• site selection
  • documenting with digital photos
    • basic information, 86
    • electrical information, 89–90
    • site information, 86–87
    • structural and mechanical information, 87–89
  • interpreting data
    • analyzing reports, 98
    • total solar resource factor (TSRF), 98–100
    • using other collected information, 100–101
  • for maximizing energy, 367–368
  • measuring information in degrees
    • calculating array’s azimuth, 94–95
    • calculating array’s tilt angle, 93–94
    • magnetic declination, 91–92
  • shading-analysis tools, 95–97
  • site surveys
    • site-survey bag, 83–84
    • site-survey form, 83
    • time requirements, 82
• sizing
  • battery-based systems
    • battery banks, 222–228
    • charge controllers, 232–236
    • generators, 241–242
    • inverters, 236–239
    • loads, 216–219
    • overview, 215–216
    • PV arrays, 229–232
  • conductors
    • conditions of use, 247–250
    • determining sizing, 250–252
    • maximum and continuous current of circuits, 245–246
    • non-PV circuit maximum current, 246–247
    • overview, 244
    • voltage drops after sizing, 253–257
  • conduit, 257–258
  • equipment-grounding conductors, 325–326
  • grid-direct systems
    • budget and available array area, 190–191
    • combining power and voltage information, 213–214
    • estimating annual energy production, 191–192
    • inverters, 196–197, 214
    • power values for arrays and inverters, 197–199
    • sizing arrays, 193–196
  • grounding, 328–329
  • overcurrent protection devices and disconnects
    • on inverter circuits, 260
    • overview, 258–259
    • on PV circuits, 259–260
  • overview, 16
  • process of, 16
  • utility-interactive systems, 229
• slime, 322
• small transformers, 163
• smartphones, 95
• snow loading, 303, 308
• SOC (state of charge), 131
• soiling, 371
• Solar ABCs, 210
• Solar America Board for Codes and Standards, 274
• solar cells
  • construction and manufacturing, 106–107
  • creating one-way electron paths with PN junctions, 107
  • doping to create semiconductors, 106–107
  • photovoltaic effect, 108
  • temperature of, 119
• solar noon, 62, 75
• Solar Pathfinder, 96–97
• solar radiation
  • direct and diffuse, 60–61
  • irradiance
    • charts, 62–63
    • current and voltage, 64
    • factors of, 62
    • measuring with a pyronometer, 64–65
    • overview, 61–62
  • irradiation, 65–66
  • peak sun hours
    • calculating energy outputs, 66–67
    • charts and maps, 67–69
    • overview, 66
  • positioning PV modules
    • orienting arrays to azimuth, 79–80
    • tilt angles, 77–79
  • sun’s path on earth
    • altitude, 72–73
    • azimuth, 73–74
    • overview, 69–70
    • seasonal effects, 70–72
    • solar time, 74
    • solar window, 76–77
    • sun charts, 74–76
• Solar Radiation Data Manual for Flat-Plate and Concentrating Collectors (NREL), 67
• solar resource, 59
• solar time, 74
• solar window, 13, 76–77
• solar-access laws, 86
• SolarPro magazine, 185, 308, 310
• Solmetric SunEye tool, 97
• Solmetric Web site, 100
• solstices, 70
• source circuits, 174, 244
• Southern Hemisphere, 70
• spec (specification) sheets, 263
• special duty (Type IAA) ladder, 280
• specifying
  • charge controllers, 156
  • inverters
    • battery-based, 170–171
    • grid-direct, 169–170
    • overview, 168–169
• spring equinox, 70, 71, 73
• stacked inverters, 168, 237
• stand-alone inverters
  • low-frequency transformer technology, 168
  • overview, 15, 24, 157, 166
  • safety features, 167–168
  • sizes of, 168
  • user interface, 168
• stand-alone systems
  • average daily energy consumption for, 219–221
  • labeling guidelines for, 352–353
  • sizing
    • arrays, 229
    • calculating, 231–232
    • efficiency values, 230–231
    • overview, 230
    • peak sun hours, 231
    • total available solar resource, 231
• state of charge (SOC), 131
• stationary mounts, 80
• stationary racking systems, 80
• status meters, 152
• stepladder, 279
• stock labels, 366
• straight ladder, 279
• string inverters, 162
• strings, 145–146, 212–213
• structural engineers, 88, 270
• structural information, 87–89
• structural support, 362–363
• subpanels, 89
• substrates, 111
• sulfation, 134
• summer solstice, 70–73, 75
• summertime, 36, 209
• sun
  • charts, 74–76
  • direct and diffuse radiation, 60–61
  • irradiance
    • charts, 62–63
    • current and voltage, 64
    • factors of, 62
    • measuring with a pyronometer, 64–65
    • overview, 61–62
  • irradiation, 65–66
  • path on earth
    • altitude, 72–73
    • azimuth, 73–74
    • overview, 69–70
    • seasonal effects, 70–72
    • solar time, 74
    • solar window, 76–77
    • sun charts, 74–76
  • peak hours
    • calculating energy output, 66–67
    • charts and maps, 67–69
    • overview, 66
  • positioning PV modules, 77–80
• SunEye tool, 97
• sunlight, 108
• sunscreen, 278
• surge ratings, 171, 238–239
• surveying test conditions
  • irradiance effects on, 122
  • standard test conditions, 119–120
  • temperature effects on, 120–121
• system commissioning form, 344
• system ground connections, 327–328

T

• tag out, 288
• tape measure, 94
• tellurium, 112
• temperature
  • of battery banks, 223–224
  • coefficients of, 121, 202–203
  • compensation value, 227
  • considerations, 248
  • derate factor, 224
  • effect on capacity, 139
  • effects on surveying test conditions, 120–121
  • IV curves, 123–124
  • minimum DC voltage contribution, 209–210
  • voltage adjusted to, 348

• 10-in-1 screwdriver, 343

• terminals, 132, 250
• terminations, 175
• thermometer, 343
• THHN (heat-resistant thermoplastic), 177
• thin film modules
  • amorphous silicon, 112
  • cadmium telluride, 112–113
  • copper indium gallium diselinide, 113
  • overview, 111–112
• three-dimensional drawing programs, 87
• three-stage charging, 149
• THWN-2 (moisture and heat resistant thermoplastic), 177, 364
• tilt and orientation factor (TOF), 98–99
• tilt angles
  • calculating, 93–94
  • overview, 13, 77–79
• tilt-up racking, 297–299, 308
• time-of-use metering option (TOU), 194
• tinted safety glasses, 84
• title page, 271
• TOF (tilt and orientation factor), 98–99
• tool bags, 283
• tool belts, 283
• tools
  • safety, 278
  • shading-analysis, 95–97
  • storing safely, 283–284
• top-down mounting, 297
• top-of-pole mounting, 302–303, 313–314
• torque of battery banks, 356
• total circuit length (L), 256
• total global radiation, 61
• total solar resource factor (TSRF), 98–100, 192
• TOU (time-of-use metering option), 194
• tracking systems, 80, 302–303
• transformer-less technology, 163–164, 176–177
• transformers
  • and high-frequency technology, 163
  • and low-frequency technology, 163
• Tropic of Cancer, 72
• Tropic of Capricorn, 72
• true south, 91
• true-up period, 194, 329
• TSRF (total solar resource factor), 98–100, 192
• tubing, 180

• 2-percent design temperature, 210

• Type I (heavy duty) ladder, 280
• Type IA (extra heavy duty) ladder, 280
• Type IAA (special duty) ladder, 280
• Type III (light duty) ladder, 280

U

• Ufer ground, 327
• UL (Underwriters Laboratory), 118–119
• UL1741 test, 160
• under load, 290
• underground service entrance (USE-2)
  • battery wiring, 178
  • cables, 176
  • overview, 176
  • wire, 363
• Underwriters Laboratory (UL), 118–119
• ungrounded current-carrying conductors, 320
• ungrounded inverters, 164
• USE-2. See underground service entrance (USE-2)
• user interface
  • of battery-based inverters, 168
  • of grid-direct inverters, 161
  • of stand-alone inverters, 168
• utilitiy
  • battery-based inverters, 165–166
  • connecting to
    • backfed circuit breakers, 333
    • circuit breakers with correct rating, 332
    • fastening kits, 333
    • ground fault protection integrated into overcurrent protection device, 332
    • locating protection, 333
    • panels with multiple power sources, 333
    • placing inverters on circuit breakers or disconnects, 332
    • requirements, 329–330
  • contract with, 194–195
  • grid, 369
  • interconnection of, 27–29
  • requirements of, 101, 329–330
  • voltage of, 369
• utility-interactive systems
  • energy required during outages for, 219
  • exercising battery banks in, 356
  • incorporating generators into, 239–240
  • inverters, 15, 24
  • labeling guidelines for, 352–353
  • sizing PV arrays, 229

V

• valve-regulated lead-acid batteries (VRLA), 134–136
• vantage point, 85
• V_drop, 256
• vents, 130
• vertical walls, 77
• viewing glass, 94
• voltage
  • coefficient values, 120
  • combining with power information, 213–214
  • drops after sizing
    • AC voltage, 256–257
    • DC voltage, 254–256
    • overview, 253–254
  • equation for, 52
  • inverters
    • AC voltage, 200
    • DC voltage window, 200–201
  • irradiance, 64
  • maximum DC voltage contribution
    • adjusted open circuit voltage, 206–207
    • NEC^® info, 205–206
    • overview, 201–202
    • temperature coefficients, 202–203
  • measuring, 44–46
  • minimum DC voltage contribution
    • calculating, 211–212
    • long-term performance, 208–209
    • mounting, 210
    • number of modules needed in strings, 212–213
    • overview, 208
    • temperature, 209–210
  • nominal and operating, 43–44
  • overview, 43, 199–200
  • ratings, 341
  • relating in IV curves
    • overview, 122–123
    • with varying irradiance, 124–125
    • with varying temperature, 123–124
  • sizing charge controllers, 233–234
  • specifications for PV modules, 115–116
  • temperature coefficient of, 117–118
  • viewing outputs, 237
  • window of, 199
• volts, 49
• VRLA (valve-regulated lead-acid batteries), 134–136

W

• W (watts), 50
• walkways, 285
• water damming, 299
• watering flooded batteries, 356–357
• wattage, 51
• watt-hours (Wh), 53, 138
• watts (W), 50
• watts per square meter (W/m²), 61–62
• well pumps, 217
• western declination, 91–92
• wet stamp, 269
• Wh (watt-hours), 53, 138
• wheel tape, 84
• white wires, 319–321
• wind loading, 307–308
• wind systems, 144
• winter solstice, 70, 72, 73
• wintertime, 36
• wire cable clips, 364
• wire ties, 364
• wiring
  • battery banks, 227–228
  • circuits, 174–175
  • color-coding, 319–321
  • conductors
    • battery wiring, 178
    • building wiring, 177
    • ground wiring, 178
    • overview, 175–176
    • PV wire, 176–177
    • underground service entrance, 176
  • conduit
    • metallic, 179–180
    • nonmetallic, 180–181
    • overview, 179
  • connections, 354
  • disconnects, 181–182
  • ground fault protection, 184–185
  • integrating, 318–319
  • labels, 185–186
  • overcurrent protection devices
    • circuit breakers, 183
    • fuses, 183–184
  • overview, 15–16
  • protecting with conduit, 322
  • on PV modules, 321–322

Z

• zenith, 73, 75
• zero point, 73, 74
• zeroing meters, 42
• zip ties, 322