New to Solar? 65 PV Plant FAQs to Solve Your Doubts – PART 2

In the first part of this series, we covered some of the most common basic questions about PV plants, giving newcomers a clearer starting point. In this second part, we’ll go further by addressing additional frequently asked questions that often arise during project planning and installation. Our goal is to provide clear, practical answers that will help you move forward with more confidence on your solar journey. New to solar? 65 PV plant FAQs to solve your doubts! Read on the second part.

A: We must not stack the flammable and explosive materials near distributed power generation systems. A fire could cause immeasurable loss of life and property. In addition to basic fire safety measures, we require PV systems to specifically have self-detection and arc and fire identification capabilities to reduce the likelihood of fire. Furthermore, we must reserve the fire and maintenance access routes every 40 meters, and readily accessible emergency DC system circuit breakers must be available.

A: We primarily categorize the lightning strikes into two types: direct and indirect. To protect against direct lightning strikes, we install the metal lightning conductors on tall buildings to dissipate the massive electrical charge from thunderstorm clouds. To protect against induced lightning, we incorporate lightning arresters into the PV system. This involves adding lightning protection modules to electrical equipment such as combiner boxes and inverters to protect against indirect lightning strikes.

A: If the power generated by a distributed PV power generation project cannot meet the electricity needs of the project’s corresponding power users, the power grid company must assume the same power supply responsibility as ordinary power users.

For this operating model, we locate the photovoltaic grid connection point on the load side of the user’s meter. We require a meter for solar power feedback, or configure the grid meter for bidirectional metering. The solar power directly consumed by the user will be directly charged the grid’s sales price, saving on electricity bills. We will seperately meter the feedback power and settle it at the prescribed on-grid tariff.

A: The power generation of a photovoltaic system is indeed affected by temperature, but the impact is very small. The factors that directly affect power generation are irradiation intensity and sunshine, as well as the operating temperature of the solar cell modules. In winter, temperatures are lower and daylight hours are shorter, so power generation is generally lower than in summer, which is normal.

A: We can store the power generated by a distributed PV system during the day for use as lighting at night. This requires adding electrical components such as a controller and batteries. The controller stores the solar power in the battery during the day and releases it at night for lighting. Without energy storage, the system will cease functioning if the grid goes out. However, if we replace the grid-connected inverter with a smart microgrid inverter (a hybrid inverter combining grid-connected and off-grid operation), the system will continue to operate normally.

A: PV panels can generate power even in low light conditions. Haze does affect photovoltaic power generation, but the reduction in efficiency is no more than 5% (except in severe haze). Generally, power generation on rainy days is only about 10%-20% of normal levels. Due to continuous rain or haze, the solar radiation intensity is low. If the operating voltage of the photovoltaic system does not reach the inverter’s starting voltage, the system will not operate. The grid-connected power generation system operates in parallel with the distribution network. When the photovoltaic system cannot meet the load demand and stops operating, the grid will automatically replenish the power, eliminating power shortages and outages.

A: Absolutely not, as the system monitoring is fully automatic. It will start and shut down automatically, eliminating the need for manual control.

A: The maximum operating temperature range of photovoltaic panels is -40°C to 85°C. We recommend to install them in an environment with a temperature range of -20°C to 50°C, which represents the monthly average minimum and maximum temperatures at the installation site. There is no altitude requirement for panel installation, but we must consider the altitude restrictions of other supporting electrical equipment.

A: PV panels generate electricity whenever there is sunlight, and the series voltage can be high relative to ground. Therefore, installation must strictly follow the supplier’s instructions and be carried out by professionals. All wiring should use IP65-rated connectors, and electrical equipment must be protected by circuit breakers. Extra care should also be taken in rain or snow. Key requirements:

a. Use insulated tools when installing panels; avoid metal jewelry.
b. Do not disconnect connections under load.
c. Keep connectors dry/clean; never insert metal objects.
d. Do not touch damaged panels unless disconnected and wearing protective gear.
e. Do not touch wet panels except when cleaning per manual; always wear protective gear or rubber gloves.

A: Conventional crystalline silicon modules come with a 10-year limited product warranty, meaning we can repair or replace them within ten years. In addition, they offer a 25-year limited peak power warranty, guaranteeing that the module’s peak power degradation remains within a certain range.

A: Common aging symptoms of crystalline silicon modules include cell breakage, hot spots, EVA yellowing, backsheet cracking, and snail patterns, which are visible to the naked eye. Hot spots, poor solder joints in the junction box, diode failure, and electrothermal induced degradation, while not visible to the naked eye, can cause significant uneven heating of the cells within the module and a significant drop in power generation. These can be detected through technical means. Regular module inspections and power generation tracking can indicate a potential module failure if any obvious visual abnormalities or a sudden drop in power generation are detected. We recommend that PV power plants, where possible, you should equip it with infrared thermal imagers to quickly identify and locate problematic modules by measuring temperature differences on the surface of the PV module film. If you discover a module failure, please contact the manufacturer promptly for analysis and resolution. Do not attempt to repair the failed module yourself.

Answer: Owners can make a preliminary assessment based on several factors. First, inspect the system’s appearance, including the modules, array, and combiner box. If you find any issues, such as module damage, obstruction, or dust, take appropriate measures to resolve them promptly. Also, verify that the system components used by the power plant construction contractor have quality certifications. Additionally, conduct on-site safety tests for system safety, such as grounding continuity, insulation, and lightning protection. We should also test the system’s electrical efficiency. If you find any issues, you should contact the power plant construction contractor to resolve them promptly.

A: If the user notices a decrease in system power generation during the same season, or compare a decrease to neighboring systems of the same capacity, the system may be experiencing an anomaly. Users can detect abnormal fluctuations in the combiner box’s monitoring data to promptly identify faults in a particular string of modules in the PV array. They can then contact professionals to diagnose the system using specialized equipment such as clamp meters and thermal imagers, ultimately identifying the problematic module.

A: According to relevant national laws,we do not consider rooftop distributed PV power systems as illegal construction. As long as we submit the application through legal channels and design and constructe the PV power station properly, the State Grid will connect the system to the grid and provide subsidies on time. Currently, there is extensive market experience in the construction and installation of home PV power generation systems. There is no modifications requirement to the building; determine the installation solely based on the roof’s conditions. Whether pre- or post-renovation, installation is unaffected. The modules offer a beautiful finish, uniform color, and excellent integration with the building, making them ideal for rooftop power generation projects.

A: First, according to the hail test results in the product description, the photovoltaic modules can withstand hail impacts of up to 44m/s and a diameter of 35mm. The modules’ compressive strength and ability to operate in harsh environments have been certified by international professional organizations. Secondly, we generally recommend that owners seek insurance from a reputable insurance company for their solar power plants. With insurance, they will receive compensation in the event of a natural disaster.

A: Wind power converts mechanical potential energy into electrical energy. The rotation of wind turbines creates noise pollution and has a certain impact on the ecological environment. Therefore, they are not suitable for urban construction and are generally built in deserts or shallow coastal areas. Solar power generation uses solar panels to absorb solar radiation and convert it into electricity. This involves no mechanical work, noise pollution, or radiation. Currently, there are two main types of photovoltaic power plants: large-scale ground-mounted power plants, we mainly locate them in sparsely populated areas in the northwest; and distributed photovoltaic power plants, such as those on household rooftops, commercial and industrial rooftops, and fish-to-solar hybrid systems. Both models do not cause climate or ecological damage, but rather reduce carbon dioxide emissions and improve ecological quality.

A: 1. We recommend not to use different module models in the same solar system. When connecting modules in series, the voltage of each string cannot exceed the maximum system voltage. We determine the maximum number of modules in series by the formula: module system voltage (1.25 * open-circuit voltage).

2. When connecting modules in parallel, we recommend that the output current of the entire string equal the sum of the currents of each branch or string. We must equip each string of modules with a fuse. We should consult national, regional, or local regulations. We need to calculate the connection of the maximum number of modules in parallel using the formula: maximum protection current / short-circuit current + 1.

A: 1. For recommendation, that ground all non-current-carrying metal components and equipment casings in a PV power generation system, such as the PV modules, PV module brackets, inverter casing, and grid-connector box. PV modules have prefabricated grounding holes for direct series connection for protective grounding. We can ground directly or connect the inverter ground terminal in parallel with the grid-connector cabinet’s base line for combined grounding.

2. After system installation and before commissioning, an insulation test using a megohmmeter should be performed by two electrical technicians.

A: Generally, we select an inverter with the appropriate power range based on system requirements. The power of the selected inverter should match the maximum power of the PV array. Generally, a PV inverter with a rated output power close to the total input power is selected to save costs. Generally, a 1:1 ratio is sufficient, but the inverters are capable of over-rating by more than 1.2 times.

A: MPPT stands for Maximum Power Point Tracking. It refers to the inverter’s ability to consistently maintain the maximum output power of solar panels. This function originates from the inverter and affects the panels. MPPT efficiency is a key indicator of an inverter’s efficient power generation.

A: IP65 represents the inverter’s protection rating. String inverters generally require an IP65 rating to ensure that we can install them outdoors and provide protection from sunlight.

A: Inverters have multiple monitoring methods, including wired and wireless. Wired monitoring allows data collection via the RS485 port, which we can convert them to an Ethernet port for access to an internet monitoring cloud platform.

Wireless monitoring allows access to an internet monitoring cloud platform by optionally connecting a Wi-Fi or GPRS/3G module to the RS232 port. After the inverter is connected to the Internet cloud monitoring platform, we can view the inverter-related data information through the web page and mobile APP at the same time.

So for new to solar, here is the second part of 65 PV plant FAQs to solve your doubts, in next few days we will publish the last part. If you are interested in knowing more or sharing insights with us, please feel free to contact.