A homeowner wanted a 5 kW system to offset their electricity bill.

Determine the appropriate number of panels, inverter size, and layout.

I first performed an energy audit using past utility bills, calculated the daily kWh usage, and applied the local solar insolation factor. I selected 15 × 330 W panels and a 5 kW inverter, ensuring the roof could accommodate the array with proper orientation and shading analysis. I also accounted for code‑required conduit sizing and voltage drop.

The design met the homeowner’s energy goals, passed the local permitting review on the first submission, and stayed within the client’s budget.

During a commercial rooftop installation, the array required multiple strings to be combined.

Explain the role of the combiner box and outline safe installation practices.

I described that a combiner box consolidates multiple string conductors into a single feeder, providing over‑current protection via fuses or breakers. For safety, I ensured the box was mounted on a fire‑rated surface, used proper grounding, kept clearances per NEC 690.31, and performed lock‑out/tag‑out before wiring. I also verified that conduit fill and wire gauge matched the calculated current.

The combiner box passed inspection without issues, and the system operated reliably with no hot‑spot incidents.

A new 10 kW residential system was completed and needed commissioning before hand‑over.

Perform a systematic start‑up, verify electrical parameters, and ensure the system meets performance guarantees.

I began with a visual inspection, then used a multimeter to confirm open‑circuit voltage (Voc) and short‑circuit current (Isc) for each string. I checked inverter settings, performed a grid‑synchronization test, and used the monitoring software to compare real‑time output against the expected production model. Any discrepancies triggered a troubleshooting loop—checking connections, string mismatches, or inverter logs.

The system achieved 98% of the projected output in the first week, and the homeowner received a detailed performance report.

I was assigned to install panels on a 30°‑pitch roof with limited anchorage points.

Ensure personal safety while completing the installation efficiently.

I performed a site risk assessment, secured a full‑body harness to a certified roof anchor, used a fall‑arrest system, and wore non‑slip shoes. I also set up a safety line, used a ladder with a stabilizer, and kept tools tethered. Weather conditions were monitored, and work was halted if wind exceeded 15 mph.

The installation was completed without any incidents, and the safety audit recorded zero violations.

During a new residential installation, the local inspector required full NEC compliance.

Apply NEC requirements throughout the installation process.

I reviewed NEC 2020 Chapter 9, especially Articles 690.31 (combiner boxes), 690.41 (inverter connections), and 690.70 (grounding). I selected conduit sizes to meet fill tables, used listed PV wire, installed grounding electrodes per 250.50, and labeled all circuits. I also prepared a compliance checklist and submitted detailed as‑built drawings before the final inspection.

The inspector approved the installation on the first review, and the homeowner received a certificate of compliance.

A homeowner noticed a sudden drop in system output after a storm.

Explain the cause and proposed solution in layman's terms.

I visited the site, inspected the array, and discovered a few panels were shaded by fallen branches. I used a tablet to show before‑and‑after photos, explained how shading reduces power, and outlined the trimming process. I also provided a simple cost estimate and timeline.

The homeowner approved the work immediately, and after clearing the debris, system output returned to expected levels, earning a positive review.

Two residential projects were scheduled to start the same week, but crew availability was limited.

Create a realistic schedule that meets both clients’ expectations.

I mapped out each project's critical path, identified tasks that could be overlapped (e.g., permitting, site surveys), and allocated crew members based on skill sets. I communicated the adjusted timeline to both homeowners, offered a slight discount for the later start, and set up daily check‑ins to monitor progress.

Both installations were completed on time, the clients were satisfied with the transparency, and the company received repeat referrals.

During a rooftop install, the lead electrician and I disagreed on the placement of a conduit that could affect roof penetrations.

Find a safe, code‑compliant solution while maintaining team cohesion.

I initiated a brief sit‑down, listened to his concerns about structural integrity, and presented my layout plan referencing NEC 690.31 and the roof manufacturer’s guidelines. We consulted the project manager and used a laser level to test both options. Together we selected the route that minimized penetrations and met safety standards, documenting the decision for future reference.

The installation proceeded without additional roof damage, the team felt heard, and the project manager praised our collaborative problem‑solving.