12 - Alternative Energy and Generators: Solar PV, Wind Turbines, Generators

Send us Fan MailAlternative energy systems are increasingly common but typically out of scope for standard home inspections. This episode introduces these systems and helps inspectors recognize components and limitations.Common Residential Systems:Solar photovoltaic (PV)Wind turbinesSolar water heatingPassive solar designGround-source heat pumpsWater-source heat pumpsHome Inspector Actions:Report presence of systemDisclaim inspectionRecommend specialist evaluation for condition and functionNote permit requirements (few systems may be installed without permits)Solar Photovoltaic (PV) SystemsGrid-Connected (Most Common):Connected to utility gridProvides some/all occupant electricity during daylightUtility provides electricity when system insufficientExcess electricity fed back to grid (net metering—utility may pay)Most systems home inspectors see are grid-connectedStand-Alone:Not connected to utility gridMay serve one/few loads or entire houseBatteries/generators provide power at nightMay include wind turbine supplementSystem Components:Solar arrays (panels on roof/ground)DC disconnect switch (service/safety device)Inverter (converts DC to AC)AC disconnect switch (service/safety device)Backfed circuit breaker (connects to house panel—should be labeled and secured)Conduit/conductors (EMT, MC common)Mounting hardwareWaterproofing (roof/wall penetrations)Key Requirements:PV conductors identified where accessiblePV conductors NOT in same conduit as other system conductorsConduit/boxes labeled as containing PV conductorsNon-current-carrying metal parts groundedEmergency access pathways on roof (new requirement—36" wide, separate planes)Arrays set back from roof ridge 18-36" (new requirement)Typical Defects (If Reported):PV system disconnected/not functioning (check inverter display)Backfed breaker not secured in panelboardComponents not labeledAbsent disconnect switchesExposed conductorsMetal components not bondedPanels cover vents/exhausts (okay if adequate spacing)Damaged panels (scratched glass)Significant shading of arraysWind TurbinesKey Components:Rotor and generator moduleInverter, disconnects (similar to solar PV)Tower (self-supporting or guy cables)Surge protective device (lightning arrestor)Grounding electrode connectionGeneratorsTransfer Switch (REQUIRED):Disconnects house from grid while generator provides powerPrevents dangerous backfeeding into utility grid (fatal shock hazard to utility workers)May be automatic or manualKey TakeawaysAlternative energy systems typically out of scopeReport presence, disclaim, recommend specialist evaluationSolar PV most common alternative energy systemGenerators require transfer switches (prevent backfeeding)Few systems may be installed without permitsIRC/NEC ReferencesIRC 2018: R324, R327, Chapter 23 NEC 2017: Article 690 (PV), Article 694 (wind)Intro This episode is brought to you by GetSync.pro This episode is hosted by Charlie Bellefontaine of Chicagoland Home InspectorsFor complete training with visual materials, practice exams, and certification support, visit nhiexamprep.com© 2025 National Home Inspector Exam Prep Podcast. All rights reserved.