The typical PV systems drawn as clear wiring diagrams and explained step by step: string inverter, microinverters, DC optimizers, combiners and disconnects, the connection to the main panel, a supply-side connection, battery backup with a critical loads panel, off-grid systems, grounding and the line diagram for the permit set. Always follow the NEC edition your AHJ enforces.

Home battery storage for solar installers explained with drawings: how batteries work, kWh and kW, lithium iron phosphate and other chemistries, AC and DC coupling, backup and critical loads, self-use and time of use, sizing step by step, installation basics, safety and the rules of NEC Article 706 as concepts.

PV system design explained with drawings and worked examples calculated step by step: the load from the utility bill, sun hours, losses, array size, module count and roof fit, string sizing for cold and heat, inverter matching, conductor and overcurrent sizing, the 120% rule, voltage drop and the permit set. Generic practice examples: always follow the NEC edition your AHJ enforces.