Interview Questions for NABCEP Certification

Think of a solar panel system like a LEGO castle. A PV module is a single LEGO brick – a complete, self-contained unit that converts sunlight into electricity. A PV array is the entire castle, built from many individual LEGO bricks (modules) connected together to generate a larger amount of power. Each module produces a relatively small amount of electricity, but connecting many modules in series and parallel creates an array capable of supplying significant power to a home or business.

In simpler terms: A PV module is a single solar panel, while a PV array is a collection of multiple solar panels wired together to increase the system’s overall power output.

Grounding a PV system is crucial for safety, protecting against electrical shocks and preventing damage from lightning strikes. The process involves creating a low-resistance path to the earth for any stray electrical current. This is typically achieved by connecting the PV system’s grounding electrode to a grounding rod driven into the earth and connecting that rod to the system’s metal components (like the racking system and array). It’s important to ensure all metal parts of the system are adequately bonded together to create a continuous, low-impedance path to ground. This process needs to be completed according to local electrical codes and standards.

Imagine it as creating a safety valve for electricity. If a fault occurs, the grounding system provides a safe path for current to flow into the earth, preventing dangerous voltage buildup on the system components.

Working on a live PV system is extremely dangerous. The most critical safety precaution is to always assume the system is energized until you’ve verified it’s completely de-energized and locked out/tagged out. This involves disconnecting the system from the inverter and verifying that there’s no voltage present using a properly rated voltage detector. Never rely solely on visual inspection. Other vital precautions include:

• Wearing appropriate personal protective equipment (PPE), including safety glasses, gloves, and insulated tools.
• Using insulated tools to avoid accidental contact with live conductors.
• Having a qualified spotter present to assist and ensure safety.
• Understanding the system’s design and knowing the location of all components.
• Following all applicable safety regulations and codes, including those set by OSHA and relevant local authorities.

Ignoring these precautions can lead to serious injury or death.

Sizing a PV system involves determining the appropriate amount of solar panels to meet the energy demands of a specific load. This requires careful consideration of several factors:

• Annual energy consumption: Calculate the total kilowatt-hours (kWh) consumed by the load annually.
• Solar irradiance: Determine the average amount of sunlight received at the installation location.
• System efficiency: Consider the efficiency of the PV modules, inverter, and other components.
• Derating factors: Account for factors that reduce system output, such as shading, temperature, and system losses.

Using this data and specialized software or online calculators, you can estimate the required PV system size. For example, if a home uses 10,000 kWh annually, and the derating factor is 80%, you would need a system capable of generating 12,500 kWh annually (10,000 kWh / 0.80).

PV inverters convert the DC electricity produced by solar panels into AC electricity usable by homes and businesses. Several types exist:

• String inverters: Simple, cost-effective, and connect to a single string of PV modules. They are suitable for smaller systems but less efficient in shaded conditions.
• Microinverters: Connect to individual PV modules, optimizing energy production even with partial shading. More expensive but highly efficient and offer better monitoring capabilities.
• Power optimizers: Similar to microinverters, but they require a central inverter for conversion to AC power, offering a balance between cost and performance. They are less expensive than microinverters but still provide some of the advantages of improved energy production in partially shaded conditions.
• Central inverters: Used for larger systems, converting power from multiple strings of modules. They offer higher efficiency than string inverters for larger systems but are more susceptible to losses from shading.

The choice depends on system size, budget, shading conditions, and monitoring requirements.

Numerous factors can lead to PV system faults. Some common causes include:

• Faulty PV modules: Damaged cells, cracks, or manufacturing defects can reduce output or cause complete failure.
• Wiring issues: Loose connections, corrosion, or damaged wiring can interrupt current flow.
• Inverter malfunctions: Component failures, overheating, or software glitches can cause the inverter to shut down or operate inefficiently.
• Shading: Even partial shading of PV modules can significantly reduce the array’s overall output.
• Environmental factors: Extreme temperatures, snow accumulation, or bird droppings can affect performance.
• Ground faults: Damaged grounding systems can create safety hazards and reduce system performance.

Regular system inspections and preventative maintenance are essential to minimize these issues.

Troubleshooting a PV system with low output requires a systematic approach:

1. Visual inspection: Check for obvious problems like damaged modules, loose connections, shading, or debris on the panels.
2. Check the inverter: Verify that it is functioning correctly. Check for error codes and consult the manufacturer’s documentation.
3. Measure voltage and current: Use a multimeter to measure the voltage and current at different points in the system, comparing readings to expected values.
4. Check the wiring: Examine all wiring connections for loose or corroded contacts.
5. Test individual modules: If possible, test individual PV modules to identify any faulty units.
6. Analyze weather data: Low sunlight or high temperatures can reduce output.
7. Consult system documentation: Refer to the system’s design and installation documentation.

Remember to always disconnect the system and lockout/tagout before performing any measurements or repairs.

PV racking systems are crucial for securely mounting solar panels on roofs or ground mounts. The choice depends heavily on factors like roof type, panel orientation, and the overall system design. There are several main types:

• Roof-Mount Racking: These are designed for various roof types (tile, shingle, flat). They can be either integrated into the roof structure or attached to it. Examples include rail systems, which use rails to hold the panels, and ballast systems, which use weight to secure the panels to a flat roof. Proper penetration sealing is paramount to prevent leaks.
• Ground-Mount Racking: These are used for large-scale solar farms or ground-mounted residential systems. They usually involve sturdy posts driven into the ground, with a framework supporting the panels. They often require concrete footings for stability and can be either fixed-tilt or tracking systems to optimize sun exposure.
• Pole-Mount Racking: This type typically uses a single pole or several poles to support the array. It’s common in areas with limited space or when ground conditions are challenging.
• Tracking Systems: These are more advanced systems designed to follow the sun’s path throughout the day, maximizing energy production. They can be single-axis (tracking east-west) or dual-axis (tracking both east-west and north-south).

Selecting the right racking system requires careful consideration of safety, structural integrity, and cost-effectiveness. A qualified installer will conduct a thorough site assessment to determine the optimal system.

System grounding and bonding in PV installations are critical for safety and to protect against electrical hazards. Grounding provides a low-impedance path to the earth for fault currents, preventing dangerous voltage buildup. Bonding connects metallic parts of the system to ensure they are at the same electrical potential, eliminating voltage differences that could lead to arcing and fires.

Imagine a scenario where a faulty wire shorts to the frame of a solar panel. If the system is properly grounded, the fault current will safely flow to the earth through the grounding wire. Without grounding, the panel frame could become energized, posing a severe shock hazard. Similarly, bonding ensures that all metallic components are at the same potential, preventing dangerous voltage differences.

NEC (National Electrical Code) guidelines strictly mandate both grounding and bonding procedures to ensure safety. Improper grounding and bonding can lead to electrical shocks, fires, and equipment damage.

The NEC outlines detailed requirements for PV system installations to ensure safety and compliance. These are extensive and cover various aspects, including:

• Overcurrent Protection: Proper sizing and placement of circuit breakers, fuses, and other overcurrent protection devices are essential to prevent overloading and potential fires.
• Grounding and Bonding: As discussed earlier, adherence to grounding and bonding requirements is paramount for safety.
• Wiring Methods and Materials: Specific requirements exist for wire types, sizing, and installation techniques to ensure safe and reliable operation.
• Disconnecting Means: Easily accessible disconnects are needed to isolate the system for maintenance or emergency situations.
• Rapid Shutdown: Systems must incorporate rapid shutdown mechanisms to quickly de-energize the array during emergency situations, such as fire fighting.
• Arc Flash Hazard Mitigation: Measures to reduce arc flash hazards, a serious risk in PV systems, are mandatory.
• System Grounding Electrode System (GEC): Establishing a proper grounding electrode system is crucial.

It’s crucial for installers to be familiar with the latest NEC updates and to follow all applicable codes and standards. Ignoring NEC requirements can lead to system failure, legal issues, and most importantly, safety hazards.

Calculating the energy production of a PV system involves several factors. A simplified approach uses the following formula:

Annual Energy Production (kWh) = Panel Wattage (kWp) * Daily Sun Hours * Number of Panels * Derating Factor

Where:

• Panel Wattage (kWp): The peak power output of a single solar panel (usually specified by the manufacturer).
• Daily Sun Hours: The average number of peak sun hours per day at the system’s location. This data can be obtained from solar irradiance maps or weather data.
• Number of Panels: The total number of panels in the array.
• Derating Factor: A factor that accounts for losses due to factors like temperature, shading, soiling, and inverter efficiency. This typically ranges from 0.7 to 0.8.

Example: A system with 10 panels, each rated at 300 Wp (0.3 kWp), located in an area with 5 peak sun hours per day, and a derating factor of 0.75 would produce:

Annual Energy Production = 0.3 kWp/panel * 5 hours/day * 10 panels * 365 days/year * 0.75 = 4106.25 kWh/year

More sophisticated calculations use PVSyst or similar software to account for various other variables, like module orientation and shading profiles.

Maximum Power Point Tracking (MPPT) is a crucial function in solar inverters and charge controllers. Solar panels don’t always operate at their maximum power output. Their voltage and current vary with environmental conditions like sunlight intensity and temperature. The MPPT algorithm continuously monitors the voltage and current produced by the panels and adjusts the inverter’s input impedance to extract the maximum available power. Think of it like finding the ‘sweet spot’ on a curve.

Imagine a hill with varying slopes. The maximum power point is the highest point on this hill. The MPPT algorithm acts like a skilled climber, constantly adjusting its position to reach and stay at the peak, even if the hill’s shape (voltage and current relationship) changes due to weather conditions.

Without MPPT, the system would lose significant energy, resulting in lower efficiency. MPPT improves energy harvesting, and its implementation is widespread in modern PV systems.

PV systems can be broadly categorized into three main types:

• Grid-Tied Systems: These systems are connected to the utility grid. They feed excess power back to the grid and draw power from it when needed. This is the most common type of residential and commercial PV systems, offering simplicity and cost-effectiveness. They require a grid interconnection agreement with the local utility.
• Off-Grid Systems: These systems operate independently of the utility grid. They are commonly used in remote locations where grid access is unavailable or unreliable. They typically include battery storage to provide power during periods of low or no sunlight. They are more complex and expensive than grid-tied systems.
• Hybrid Systems: These systems combine features of both grid-tied and off-grid systems. They are connected to the utility grid but also have battery storage for backup power during outages. They offer a balance of reliability and independence, with greater cost than grid-tied systems.

The choice of system type depends on factors like location, energy needs, budget, and grid availability. A qualified professional should assess individual circumstances to determine the optimal solution.

While PV systems are environmentally beneficial by reducing reliance on fossil fuels, they do have some environmental impacts:

• Manufacturing Impacts: The production of solar panels involves the use of energy and materials, some of which can be environmentally damaging if not properly managed. This includes the extraction of silicon, and the use of certain chemicals.
• Land Use: Large-scale solar farms can require significant land areas. However, it is important to note that the land under solar panels may still support other uses such as grazing.
• End-of-Life Disposal: Proper disposal of used solar panels is crucial to avoid environmental contamination. Recycling programs are gaining traction to recover valuable materials and minimize waste.
• Water Usage: Some manufacturing processes and cleaning of panels might involve water usage.

Despite these impacts, the overall environmental benefit of PV systems, which helps reduce greenhouse gas emissions and air pollution far outweighs the disadvantages, especially when compared to fossil fuel-based energy production. Sustainable manufacturing practices and proper waste management are crucial to minimizing the environmental footprint of PV systems.

A PV system inspection is a crucial step in ensuring the safety and efficiency of a solar energy system. It involves a thorough visual examination and functional testing of all components, from the solar panels themselves to the inverters and wiring. Think of it like a comprehensive health check for your solar power plant.

Here’s a step-by-step process:

• Visual Inspection: Begin with a careful visual inspection of all panels, looking for cracks, discoloration, debris buildup (leaves, bird droppings), or any signs of physical damage. Examine the racking system for rust, looseness, or structural issues. Check the wiring for damage, proper connections, and signs of overheating.
• Performance Testing: This involves measuring the voltage and current output of individual panels and strings using a multimeter. This allows you to identify any underperforming panels or strings that may need attention or replacement. A thermal imaging camera can also be beneficial here to spot hotspots which indicate potential problems.
• Grounding and Bonding: Verify that the system’s grounding and bonding are properly installed and functioning to prevent electrical shocks and ensure safety.
• Inverter Inspection: Examine the inverter for any error codes, unusual noises, or signs of overheating. Check its connection to the grid and confirm its proper operation.
• Documentation: Thoroughly document all findings, including photos and detailed notes. This is essential for insurance purposes, future maintenance, and troubleshooting.

Example: During an inspection, you might discover a loose connection on a panel causing a significant voltage drop. This could be easily rectified but would otherwise lead to reduced system performance. Proper documentation ensures the issue is addressed and prevents future complications.

Photovoltaic (PV) cells are the heart of any solar panel, converting sunlight into electricity. Several technologies exist, each with its strengths and weaknesses:

• Crystalline Silicon: This is the most common type, further divided into monocrystalline (single crystal) and polycrystalline (multi-crystal) silicon. Monocrystalline cells are more efficient but more expensive, while polycrystalline cells are less efficient but cheaper. Imagine monocrystalline silicon as a perfect, single large crystal, while polycrystalline silicon is like a mosaic of smaller crystals.
• Thin-Film: This technology uses a thin layer of photovoltaic material deposited on a substrate. Common thin-film materials include amorphous silicon, cadmium telluride (CdTe), and copper indium gallium selenide (CIGS). Thin-film cells are generally less efficient than crystalline silicon cells but are lighter, more flexible, and can be manufactured at lower temperatures.
• Perovskite: This emerging technology shows significant promise due to its high potential efficiency and low manufacturing cost. Perovskite cells are still under development but are rapidly gaining traction.

Practical Application: The choice of PV cell technology depends on factors such as budget, available space, aesthetic considerations, and desired efficiency levels. For example, a large-scale utility project might prioritize cost-effectiveness and choose polycrystalline silicon, while a residential installation might opt for the higher efficiency of monocrystalline cells despite the higher cost.

Voltage drop refers to the reduction in voltage as electricity flows through a conductor, such as the wiring in a PV system. It’s like water flowing through a pipe – the longer and narrower the pipe, the more pressure (voltage) is lost.

Causes of Voltage Drop:

• Conductor Resistance: The primary cause is the inherent resistance of the wires themselves. Thicker wires have lower resistance and thus less voltage drop.
• Wire Length: Longer wire runs result in greater voltage drop.
• Current Flow: Higher current flow increases voltage drop.
• Connections: Poorly made or corroded connections add resistance and increase voltage drop.

Consequences: Excessive voltage drop reduces the power output of the system, decreases its efficiency, and can even damage components. It can lead to underperforming panels and wasted energy.

Mitigation: Proper wire sizing, using appropriate conductors for the current, keeping wire runs as short as possible, and ensuring clean, tight connections are crucial in minimizing voltage drop. Employing voltage drop calculations during the design phase is essential to avoid these problems.

Example: A long run of undersized wire to a distant array of panels will lead to significant voltage drop, reducing the power available at the inverter and impacting the overall system performance. Proper wire sizing during the design process will alleviate this problem.

Designing a PV system for optimal performance requires careful consideration of several factors. Think of it like building a well-oiled machine where every part works together harmoniously.

Key Design Considerations:

• Site Assessment: This includes analyzing the available sunlight (solar irradiance), shading, roof orientation, and other site-specific constraints. This determines the optimal panel placement and system size.
• Energy Needs: Accurately determining the energy consumption of the building or facility is crucial in sizing the PV system appropriately. Oversizing or undersizing can both lead to inefficiencies.
• Panel Selection: Choosing panels with the right power rating, efficiency, and temperature coefficient is important for maximizing energy production. You want to choose panels that will perform optimally under the specific site conditions.
• Inverter Selection: The inverter’s capacity should match the system’s power output. This ensures that all the power generated by the panels can be effectively converted to usable electricity.
• Wiring Design: Proper wire sizing is crucial to minimize voltage drop and ensure safety. This requires careful calculations based on wire length, current flow, and voltage.
• System Monitoring: Incorporating a monitoring system allows for real-time tracking of system performance and helps identify any potential issues early on.

Software Tools: Specialized software is used to simulate system performance under different conditions and optimize system design.

Example: A south-facing roof with minimal shading will allow for a more efficient system design compared to a north-facing roof with significant shading. The design process will account for these differences to ensure optimal energy generation.

Solar trackers adjust the angle of solar panels throughout the day to maximize their exposure to sunlight. Think of them as giving your panels a daily sunbath to improve energy output.

Types of Solar Trackers:

• Single-Axis Trackers: These trackers rotate on a single axis, typically either east-west or north-south. East-west trackers follow the sun’s path from east to west, while north-south trackers adjust to the sun’s altitude throughout the day.
• Dual-Axis Trackers: These trackers rotate on two axes, allowing for optimal sun tracking throughout the entire day. They offer the highest energy yield but are more complex and expensive.
• Fixed-Tilt Systems: These systems don’t track the sun, but are fixed at an optimal angle for the geographic location. They are simpler and cheaper but less efficient than trackers.

Practical Considerations: The choice of tracker type depends on factors such as budget, site conditions, energy requirements, and the balance between increased energy production and increased system complexity and cost. Dual-axis trackers might be justifiable in high-irradiance areas where the extra energy generation outweighs the increased cost, while a fixed-tilt system might be more suitable for simpler, less demanding projects.

Commissioning a PV system is the process of verifying that the system is installed correctly, operates safely, and performs as intended. It’s like a final quality control check before handing over the keys to a new car.

Commissioning Process:

• Pre-Commissioning: This involves checking the installation against the design specifications, ensuring all components are present and correctly installed.
• System Testing: This phase involves testing individual components and the entire system to verify that they are functioning as designed. This includes testing the DC and AC sides of the system, measuring voltage, current, and power output, and verifying compliance with safety standards.
• Performance Verification: This involves monitoring the system’s performance over a period of time to ensure that it meets the design expectations and the guaranteed performance parameters provided by the manufacturer.
• Documentation: All commissioning activities, test results, and any deviations from the design should be meticulously documented.
• Handover: Once all tests are successfully completed and the documentation is finalized, the system is handed over to the owner or operator.

Importance: Thorough commissioning ensures the safety and reliability of the PV system, minimizes potential problems, and provides assurance that the system meets its intended performance goals.

Example: During commissioning, a performance test might reveal that an inverter is not functioning at its rated capacity. This would require investigation and potential replacement before final handover to prevent future power loss.

PV system monitoring systems provide real-time data on the system’s performance, allowing for early detection of problems and optimization of energy production. Think of them as a dashboard for your solar power plant.

Types of PV System Monitoring Systems:

• Local Monitoring: This involves using a display unit connected to the inverter that provides basic information such as voltage, current, and power output. It is essentially a small screen providing immediate data.
• Remote Monitoring: This uses communication technologies such as cellular, Wi-Fi, or Ethernet to transmit data to a central location (a computer, smartphone, tablet) for remote monitoring and analysis. This offers significant benefits for early fault detection and performance optimization.
• Web-Based Monitoring: Many inverters and monitoring systems offer web-based access to performance data through a secure web portal. This allows for easy viewing of performance graphs, reports, and data analysis from anywhere with an internet connection.

Features: Most monitoring systems provide data on energy production, voltage, current, power, temperature, and inverter status. Advanced systems may also provide performance alerts, fault detection, and predictive maintenance capabilities.

Example: A remote monitoring system might alert you to a sudden drop in energy production, indicating a potential problem such as shading, a faulty panel, or a malfunctioning inverter. This early warning allows for timely intervention and prevents potential system failure.

Worker safety during PV system installation is paramount. It’s not just about following regulations; it’s about fostering a culture of safety on every job site. This starts with thorough risk assessments before any work begins. We identify potential hazards, like working at heights, electrical shock, and exposure to UV radiation, and develop a site-specific safety plan. This plan outlines the necessary Personal Protective Equipment (PPE), such as hard hats, safety glasses, gloves, and fall protection harnesses, as well as the procedures to follow.

For example, before working on a rooftop, we’d ensure proper fall protection systems are in place, including anchor points and safety lines. We also conduct regular toolbox talks to reinforce safe work practices and address any immediate concerns. Regular training on lockout/tagout procedures is crucial to prevent electrical shocks during system installation and maintenance. Finally, we maintain comprehensive incident reporting and investigation processes to learn from any mistakes and prevent their recurrence. This holistic approach ensures the well-being of our crew and the success of the project.

PV system maintenance is critical for optimal performance and longevity. It involves both preventative and corrective measures. Preventative maintenance involves regular inspections to detect potential issues before they escalate. This includes visually inspecting panels for cracks, hotspots, or debris buildup; checking connections for corrosion or loose wiring; and verifying the proper functioning of the inverter and monitoring system. We might use thermal imaging cameras to detect hotspots early, preventing potential fires or performance degradation. Corrective maintenance addresses problems identified during inspections or through system alerts. This could involve repairing or replacing damaged panels, cleaning heavily soiled panels, or repairing faulty wiring.

For example, a routine inspection might reveal a significant amount of bird droppings obstructing the sunlight reaching the panels. This would trigger a cleaning process, restoring the system’s efficiency. Another example would be replacing a failed inverter – a task requiring specialized skills and adherence to safety protocols. A well-structured maintenance plan, tailored to the specific PV system and environmental conditions, ensures long-term system reliability and maximizes return on investment.

The economic benefits of PV systems are significant and multifaceted. The most obvious is the reduction in electricity bills. By generating your own clean energy, you lessen your reliance on the grid and avoid fluctuating electricity prices. This translates to substantial long-term cost savings. Furthermore, government incentives, such as tax credits and rebates, can significantly reduce the initial investment cost. These incentives vary by location and are designed to promote the adoption of renewable energy technologies. Beyond direct cost savings, PV systems can increase the value of a property. Homeowners with solar panels often command higher selling prices, making it a smart investment from a real estate perspective. Finally, there are environmental benefits, such as reduced carbon footprint, which contribute to overall long-term sustainability and potentially increased property value due to higher demand for eco-friendly housing.

Choosing the right inverter size is crucial for optimal PV system performance. An undersized inverter will limit the system’s power output, while an oversized inverter may be less efficient and more costly. The process begins with calculating the total DC power generated by the PV array. This is done by considering the panel’s wattage, the number of panels, and their arrangement. Next, we must consider the inverter’s maximum AC output power. The inverter’s capacity must be sufficient to handle the peak power produced by the array, allowing for a safety margin. We also consider the inverter’s efficiency rating, aiming for high-efficiency models to minimize energy losses. Finally, factors like future expansion potential and compatibility with the grid requirements are taken into account. The inverter’s output should ideally match the home’s power consumption profile to maximize self-consumption and minimize reliance on grid power.

Shading significantly impacts PV system performance. Even a small amount of shading on a single panel can drastically reduce the overall output of the entire string of panels. This is due to the way PV panels are wired in series: the current flowing through the string is limited by the most shaded panel. This phenomenon is often referred to as the ‘bypass diode effect’ – where the diodes in each panel attempt to bypass the shaded cells, but still cause a reduction in overall string current. The impact is more pronounced during peak sunlight hours, resulting in significant energy loss over the course of a day. Proper system design and installation should minimize shading by careful panel placement, orientation, and consideration of nearby trees or buildings. Advanced techniques, such as microinverters or power optimizers, can help mitigate the impact of shading by allowing each panel to operate independently, regardless of shading on other panels in the array.

Several battery types are used in PV systems, each with its own advantages and disadvantages. Lead-acid batteries are a common, relatively inexpensive option, but they have shorter lifespans and lower energy density compared to other technologies. Lithium-ion batteries are becoming increasingly popular due to their higher energy density, longer lifespan, and faster charging capabilities. However, they are generally more expensive. Flow batteries offer the advantage of independent scaling of power and energy capacity, making them suitable for large-scale applications. Nickel-cadmium batteries have been used historically, but their toxicity and memory effect limit their use today. The choice of battery depends on factors such as budget, energy storage requirements, lifespan expectations, environmental impact, and the specific application. For example, a residential system might use lithium-ion for its high energy density and long lifespan, while a utility-scale system may opt for flow batteries for scalability and long-term cost-effectiveness.

Calculating the ROI of a PV system requires a thorough analysis of costs and benefits over its lifespan. First, we determine the initial investment cost, including equipment, installation, permits, and any associated fees. Next, we estimate the annual energy production of the system, taking into account factors like solar irradiance, panel efficiency, and system losses. This allows us to calculate the annual savings on electricity bills. We then account for any government incentives or tax credits that reduce the net investment cost. The annual savings are then compared to the net investment cost over the system’s projected lifespan (typically 25 years). A simple ROI calculation would be:

However, a more sophisticated approach would involve discounted cash flow analysis, which accounts for the time value of money, allowing for a more accurate representation of the investment’s profitability. This includes factoring in inflation, maintenance costs, and potential revenue from selling excess energy back to the grid. This comprehensive analysis enables a data-driven decision regarding the financial viability of a solar energy project.