Solar Panel Technician Interview Questions And Answers

1). What is Solar Energy?

Solar energy is the sun’s radiant light and heat transformed into electricity or thermal energy through photovoltaic (PV) systems (or) solar thermal technology. 

It is a renewable, sustainable, & environmentally friendly energy source that is extensively employed in home, commercial, & industrial applications.

2). What are the Different Types of Solar Energy Systems?

Solar energy systems are categorized into:

• Photovoltaic (PV) systems convert sunshine into electricity.
• Solar Thermal Systems utilize sunlight to heat water or create electricity.
• Concentrated Solar Power (CSP) harnesses solar energy to generate steam and power turbines.

3). What is a Photovoltaic (PV) System?

A photovoltaic system is made up of 

• Solar panels, 
• Inverters, 
• Charge controllers, and 
• Battery storage (for off-grid applications) 

that convert solar energy into electricity.

4). How does a Solar Panel work?

Solar panels use photovoltaic cells to absorb sunlight & generate direct current (DC) electricity. The solar inverter subsequently transforms the DC power to alternating current (AC) for usage in electrical appliances.

5). What are On-Grid (Grid-Tied) Solar Systems?

An on-grid solar system is directly connected to utility grid, allowing excess electricity to be supplied back into the grid and used as needed. 

It enables net metering, which allows users to receive credit for surplus energy production.

6). What are Off-Grid Solar Systems?

An off-grid solar system operates independently of the utility grid. It needs battery storage for storing excess electricity for usage during periods of low sunlight.

7). What is the Difference Between On-Grid and Off-Grid Solar Systems?

Feature	On-Grid System	Off-Grid System
Grid Connection	Connected to Utility Grid	Works Independently
Battery Need	Not Required	Storage Required
Net Metering	Available	Not Applicable
Power Backup	No Backup (Depending on power grid)	Provides Power Backup

8). What is the Difference Between a Solar Cell and a Solar Panel?

Solar Cell	Solar Panel
A solar cell is a single photovoltaic (PV) cell that converts sunlight to energy.	A solar panel is a module made up of multiple solar cells connected together to increase power output.

9). What is a Solar Inverter?

A solar inverter is a fundamental component in solar PV systems that converts DC power generated by solar panels into AC power for household or industrial usage.

10). What are the Different Types of Solar Inverters?

• String Inverters: Connected to multiple solar panels in a series.
• Microinverters: Installed on each panel for individual optimization.
• Central Inverters: Used in large-scale solar farms for high-capacity conversion.
• Hybrid Inverters: Combine solar & battery storage systems.

11). What are the Main Components of a Solar Inverter?

• DC Input Terminals: Connects to solar panels.
• MPPT (Maximum Power Point Tracking) Controller: Optimizes power conversion.
• Power Electronics (IGBTs, MOSFETs): Converts DC to AC.
• Cooling System (Fans/Heatsinks): Prevents overheating.
• AC Output Terminals: Delivers electricity to the load/grid.

12). What types of PV Modules have you worked with, and what challenges have you faced in maintenance?

Common PV modules include 

• Monocrystalline, 
• Polycrystalline, and 
• Thin-film solar panels. 

Maintenance challenges include 

• Dust accumulation, 
• Shading issues, 
• Pid effect, and 
• Degradation of module efficiency over time.

13). How do you check if PV modules are performing well?

• Visual Inspection – Checking for cracks, discoloration, or dirt.
• IR Thermography – Detects overheating and faulty cells.
• I-V Curve Testing – Measures current-voltage characteristics.
• Insulation Resistance Test – Ensures no electrical leaks.

14). What type of connections are used in solar modules? How many modules form an array or string?

• Series Connection: Increases voltage.
• Parallel Connection: Increases current.

A string is made up of many panels in series, while an array is a mixture of strings.

15). What is SCB (String Combiner Box) (or) AJB (Array Junction Box)? What equipment is inside?

SCB/AJB combines several solar panel strings & includes:

• Fuses and circuit breakers protect against overcurrent.
• Surge Protection Devices (SPD) can prevent voltage spikes.
• DC Isolators can Ppovide safety during maintenance.

16). How Many Strings are connected in One SCB or AJB?

In utility-scale solar farms, the number of strings varies depending on the system design, but typically ranges from 4 to 24 strings per SCB or AJB.

17). How to Troubleshoot & Diagnose issues in Solar PV Systems?

• Check voltage & current readings using a multimeter.
• Check for physical damage in panels & wiring.
• Use thermal imaging to identify hotspots.
• Monitor inverter error codes for defect diagnostics.

18). What is Solar Irradiance, and how does it affect solar energy systems?

Solar irradiance refers to the strength of sunshine per unit area (W/m²). 

It improves the efficiency of PV modules & assists in the design of optimal solar power systems.

19). What is the purpose of an inverter in a solar energy system?

A solar inverter converts DC power from the solar panels into usable AC power while improving energy efficiency with MPPT technology.

20). What are the Different Types of Solar Collectors used in Thermal Systems?

• Flat-Plate Collectors: Used for household water heating.
• Evacuated Tube Collectors: High-efficiency collectors for industrial applications.
• Parabolic Trough Collectors: Used in concentrated solar power (CSP) systems.

21). What is Net Metering and How does it work in Grid-Tied Solar Systems?

Net metering allows solar users to feed excess electricity into the grid, earning credits that can be used to offset future electricity bills.

22). What is a Solar Tracker and How does it improve Solar Panel Efficiency?

A solar tracker adjusts the angle of solar panels to follow the sun’s movement, increasing energy generation by up to 40% compared to fixed installations.

23). What are the common challenges in Solar Energy Systems?

• Weather Dependence create efficiency drops on cloudy days.
• Degradation of PV Modules causes reduced output over time
• Periodic cleaning is necessary to prevent dust and soiling losses.
• On-grid systems may experience voltage swings, causing grid instability.

24). What are the most important safety precautions for working with solar energy systems?

• Wear insulated gloves and safety gear to prevent electric shocks.
• Turn off DC/AC disconnects before maintenance to avoid live circuits.
• Proper grounding and earthing reduces the danger of electrical problems.
• Follow Lockout/Tagout (LOTO) procedures to ensure safe handling.

25). What are the most latest developments in Solar Technology?

• Bifacial Solar Panels used for capturing sunlight from both sides.
• Perovskite solar cells offer higher efficiency and flexibility in design.
• Floating solar farms minimize land use and evaporation losses.
• AI-Based Solar Monitoring improves defect identification and efficiency.