Lesson 1Sizing and specifying cables and protection: voltage drop, Ampacity, derating, and standards to referenceThis section teaches sizing and specifying PV cables and protective devices using ampacity, voltage drop, and derating factors in Namibia, referencing key standards and coordinating with fuses, breakers, and environments.
Conductor materials and insulation typesAmpacity, grouping, and temperature deratingVoltage drop limits and cable lengthFuse and breaker selection for stringsRelevant IEC and NEC cable standardsLesson 2PV module types and characteristics: monocrystalline, polycrystalline, bifacial, temperature coefficients and power toleranceThis section reviews crystalline and bifacial PV module technologies, focusing on efficiency, temperature behaviour, power tolerance, and reliability, comparing datasheets and selecting types for Namibian climates and sites.
Monocrystalline vs polycrystalline modulesBifacial modules and albedo conditionsTemperature coefficients and hot climatesPower tolerance and binning strategiesDegradation rates and warranty termsLesson 3Module electrical parameters: Vmp, Imp, Voc, Isc, STC vs NOCT, IV curves and implication for string designThis section explains key module electrical parameters and IV curves, contrasting STC and NOCT ratings, using Vmp, Imp, Voc, and Isc to predict array behaviour and inform string design and inverter matching in Namibia.
STC vs NOCT ratings and test conditionsVoc, Vmp, Isc, and Imp definitionsReading and interpreting IV curvesEffect of irradiance and temperatureImplications for string and inverter designLesson 4Earthing and lightning protection basics and local regulatory checklist for rooftop PVThis section introduces earthing, bonding, and lightning protection for Namibian rooftop PV, reviewing equipotential bonding, surge paths, air-termination systems, and a checklist aligned with local regulations and standards.
Functional vs protective earthingBonding of modules and mounting railsLightning risk assessment basicsAir terminals, down conductors, and SPDsRegulatory and inspection checklistsLesson 5String sizing: maximum input voltage, MPPT voltage window, number of modules per string, and cold-temperature correctionThis section details string sizing using module and inverter limits, including maximum DC voltage, MPPT window, and cold-temperature effects, calculating safe module counts per string for Namibian climates and grid codes.
Reading inverter DC input specificationsUsing module Voc and temperature dataCold-temperature voltage correctionMPPT window and operating marginsTools and spreadsheets for string sizingLesson 6Inverter options and tradeoffs: central/string inverters, string inverters with DC optimizers, and microinvertersThis section compares central, string, and module-level inverter options, highlighting efficiency, reliability, O&M, and layout flexibility, evaluating tradeoffs for residential, commercial, and utility-scale PV in Namibia.
Central inverters for large ground-mountsString inverters for rooftop systemsString inverters with DC optimizersMicroinverters for module-level ACRedundancy, availability, and serviceabilityLesson 7Balance-of-System (BOS): DC wiring, fuses, combiners, DC disconnect, AC breaker, AC combiner, earthing/grounding and protective devicesThis section covers DC and AC balance-of-system components in Namibia, including wiring, combiners, disconnects, breakers, grounding, and surge protection, relating functions to safety, code compliance, and reliability.
DC cable routing and segregation rulesString combiners and overcurrent protectionDC disconnects and isolation requirementsAC breakers, panels, and labelingEarthing, bonding, and fault pathsSurge protective devices for PV arraysLesson 8Choosing inverter topology considering partial shading, mismatch, monitoring, and costThis section explains how inverter topology affects shading tolerance, mismatch losses, monitoring detail, and lifecycle cost in Namibia, comparing central, string, and module-level approaches using performance and cost metrics.
Mismatch and partial shading loss mechanismsCentral vs string vs module-level layoutsMonitoring granularity and data needsCAPEX, OPEX, and LCOE comparisonsDesigning for future expansion and retrofitsLesson 9Module-level power electronics: optimizers and microinverters—installation, performance, wiring complexity and failure modesThis section examines module-level power electronics, including optimizers and microinverters in Namibia, studying installation, wiring complexity, monitoring benefits, efficiency, reliability, and failure modes in residential and C&I systems.
Optimizer vs microinverter architecturesLayout and mounting best practicesAC and DC wiring topologiesMonitoring, diagnostics, and shutdownCommon failure modes and mitigation
