What are the components of a Solar PV System?

Listed below are some of the basic components that are assembled to build a solar PV power plant that is safe to operate and generates energy to its maximum efficiency if designed and installed correctly. Scroll down to read about each component seen above: PV Modules: PV stands for Photo Voltaic. As these panels convert light (i.e. photo) into electrical power (voltage), so they are known as Photovoltaic modules. Most commonly available PV modules are of two types- Crystalline and thin-film. PV modules are given output ratings in watts (Wp). PV Module Mounting Structures: Module mounting structures (also called MMS) is used to fix PV modules on surfaces like roofs, building facades, or the ground. MMS is commonly made of three types of materials i.e. Hot Dip Galvanized Iron, Aluminium or Mild Steel (MS). Structure Foundation: Foundation or support of any structure is of utmost importance for fixation of any structure. Similarly, the PV module mounting structure foundation plays a vital role and is designed with reference to the existing soil/roof condition in order to withstand wind speed of the location depending on the type of PV installation i.e. rooftop or ground mount. Inverter: Inverter is the brain of a solar power system and serves primarily two purposes: To convert the DC power generated from Solar Panels into AC power; To ensure that generated solar energy is used at priority over grid supply. Solar inverters are essentially Grid-tied or Off-Grid/Hybrid. Junction Box: Often called as JB,  junction box i.e. AC […]

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Photovoltaic modules, its types, assembly and performance characteristics

What is a PV Module? A Photovoltaic (PV) module which is generally termed as a solar panel is an assembly of photovoltaic cells electrically connected to each other and mounted on a laminated frame. The solar cells are primarily made up of silicon material which absorbs the photons emitted by the sun. PV modules are given output ratings in watts (Wp). Types of PV Modules There are three major types of solar PV modules. Mono-crystalline Poly-crystalline (also known as multi-crystalline) Thin-film Each solar PV module type has its own unique features. These PV modules also vary based on how they’re manufactured, their appearance, performance, costs each are best suited for. Mono-crystalline and Poly-crystalline solar PV modules Both mono-crystalline and poly-crystalline solar PV modules have cells made of silicon wafers. To build a mono-crystalline or poly-crystalline module, wafers are assembled into rows and columns covered with a glass sheet, and framed together. Poly-crystalline cells are square-shaped whereas mono-crystalline cells are square with missing corners. While both of these types of solar PV modules have cells made from silicon, mono-crystalline and poly-crystalline modules vary in the composition of the silicon itself. Mono-crystalline solar cells are cut from a single, pure crystal of silicon. Alternatively, poly-crystalline solar cells are composed of fragments of silicon crystals that are melted together in a mold before being cut into wafers. Mono-crystalline modules typically have the highest efficiencies and power capacity. Thin-film solar PV modules Unlike mono-crystalline and poly-crystalline solar PV modules, thin-film modules are made from […]

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Module Mounting Structure (MMS) Design and Material

Several design elements are involved in the setting up of an efficient solar PV power plant and among them is the Module mounting structure (MMS) that withholds the heart i.e. PV modules over its lifetime.MMS allows the PV modules to be held firmly to the surface of installation (can be a roof of groud), capable of battling strong winds that could, without the careful design can damage the entire installation. MMS also becomes highly important as the generation of PV modules depend on the right tilt angle on which it is to be installed in order to raise the overall efficiency and generation capabilities of the PV power plant and this positioning based on geographical location is not possible without having a right MMS design. MMS Design Considerations Generally, module mounting structures are of three types: Hot Dip Galvanized Iron (GI) Aluminium Mild Steel (MS) Some of the design considerations to be taken care off for the construction/Installation of MMS are as follows: Comply with the applicable structural, building code and safety requirements. Meet standards and module manufacturer’s mounting requirements. Enhance array performance – allowing airflow to minimize operating temperature Provide reasonable accessibility for installation and maintenance Make the system aesthetically appropriate for the site and application. Thermal aspects – to allow expansion/contraction of modules/ structure Wind – shall be rated for the maximum expected wind speeds Material accumulation on PV array – Snow, ice, or dust Corrosion – corrosion resistant materials suitable for the lifetime and duty of the […]

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Grid Tie Solar Inverters, types and functions

Inverters are an important part of any solar PV installation that acts as the brain of the system. Although the inverter’s main job is to convert DC power produced by the solar PV modules into AC power, its role is only expanding and they provide a number of other capabilities and services to ensure that the inverter can operate at an optimal performance level. Inverters enable monitoring so installers and PV power plant owners are increasingly taking on decision-making and control functions. With the growth of solar added with storage (hybrid), inverters are also taking on responsibility for battery management. They provide: data on how the PV power plant is performing; diagnostic information to help O&M team to identify and fix issues. improved grid stability and efficiency. Types of Grid-tied solar inverters Inverters are categorised based on their features, capacity and the size of PV power plant installation. There are three common types of grid-tied solar inverters: String Inverters, Central Inverters, and Micro Inverters The functioning of a solar inverter and various types are well explained in the video by EnergyX: Sustainable Energy: Design A Renewable Future. Video copyright and property of EnergyX: Sustainable Energy: Design A Renewable Future (Youtube) 1. String Inverters A string inverter is a type most commonly used in home and commercial solar PV power plants. PV modules are installed in rows, each on a “string.” For example, if you have 25 PV modules you may have 5 rows of 5 modules. Multiple strings are connected […]

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Cables of Solar PV Power Plant Installation

The performance, quality, safety and profitability of a PV power plant doesn’t only depend on the workmanship, efficiency of PV modules and the reliability of the inverter installed, but also on the components that connect them within an electrical system. Cables are often not considered to be a highly critical factor, however, neglecting correct cables and using material that is not suitable for solar PV applications can compromise the overall performance and expected downtime of the PV power plant. Cables and wires can be considered as veins of any electrical power system including a PV power plant. The energy generated at PV  modules passing though Junction Boxes, to the Inverter and later the interconnection point with the grid is facilitated by deploying a proper and effective network of cables. As these cables are used both indoor & outdoor for flexible and fixed installations to perform in highly extreme weather conditions.These cables can be categories into two based on their functions: 1. DC Cables Installed on the DC side of the PV system, before the inverter input, the AC cables specification must include: General UV-resistant, Rated for > 1100 VDC, outdoor use If overground then UV-hardened PVC conduit If underground then Armoured From PV module to junction box 4 mm2 or 6 mm2, 1C multi-stranded Cu MC4 or equivalent PV connector From junction box to inverter Multi-core Cu Cross-section as per design (capacity & length) to limit DC cable losses <2% 2. AC Cables Installed on the AC side of the PV […]

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PV Connectors and their role in Solar PV Installation

PV Connectors are among the main components of the PV module. They are used in order to make sure that the connections are upright, doesn’t loosen and prevent misconnection. There are several types of connectors used in the solar PV industry based on the system design requirements and respective functioning. Some of the commonly used connectors in Solar PV installations are showcased in the video by LDSreliance Video copyright and property of LDSreliance (Youtube) MC4 Connectors MC4 connectors are one of the most common components used in PV power plant installation. It is a single-contact electrical connector used for connecting PV Modules, where MC in MC4 stands for the manufacturer Multi-Contact and the 4 for the 4 mm diameter contact pin for DC cable. MC4 Connectors play a crucial role in the wiring of PV arrays. As designed and if correctly installed, they provide a high-voltage, high-current, low-resistance DC connection in a housing that is waterproof, temperature resilient, UV protective and wire pull resistive. In addition, their snap-together connection technology speeds the installation of PV arrays and module connections. These connectors can also be a big reason for the PV array failure and increase system downtime. Connector failures can be found due to incompatibility issues and connector wiring problems. Following are a few insights of common PV connector failures: Poor contact crimps or crimps that have grabbed some of the wire insulation Contacts that were not installed correctly into the connector, causing high-resistance connections Water intrusion due to improperly assembled […]

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Conduits for Solar PV Installation

Conduit is a highly important and usually neglected component for protecting the electrical cables and wiring in s solar PV installation which acts as a closed channel that guards cables (both AC and DC) against hazards i.e. atmospheric or physical, over a PV installations lifetime. There are many factors to take into account to correctly size and select a conduit material, from code-, job- and customer-specific requirements, and making the right selection can make a big impact on PV power plant performance. Types of conduits Conduit used in PV power plant installations can be classified into two categories and each category can be further divided into metallic and non-metallic types. Rigid conduit Flexible conduit Rigid conduits also called as pipe or tubes, are used on higher distance runs and where extra strength or mechanical protection is required. Rigid conduits can still be turned, but flexible conduit is normally used in installations that require bending, curves or in areas where vibrations may occur. Non-metallic conduit is made from plastics that have to meet the performance requirements of steel while being much lighter, using materials like Nylon, polypropylene or PVC. The metallic conduit can be made from galvanized steel, stainless steel, brass, aluminium or nickel-plated brass. Some contain both metallic and non-metallic materials to offer low fire hazard and anti-static capabilities, external braiding and other features.   The post ID for this chapter is 3378. For any suggestion or comment regarding the content, you may write to us at faqs[dot]solar[at]gmail[dot]com. Please quote […]

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Electrical earthing and its specifications

What is Electrical earthing? The process of transferring the immediate discharge of the electrical energy directly to the earth by the help of the low resistance wire is known as the electrical earthing. The aim of earthing in electrical installations and circuits is to enhance the safety of the installation by reducing the level of danger inherent to fault currents. Fault currents may be caused by different factors. Therefore, it is very important to design an earthing system according to the installation’s characteristics. Generally in any earth system (or earth pit) measures are taken to ensure the good conductivity with low earth resistance. For this purpose water/humidity, retaining compounds like salt, charcoal, etc are used in the earth pit along with various metallic parts. Types of Electrical Earthing The electrical equipment mainly consists of two non-current carrying parts. These parts are neutral of the system or frame of the electrical equipment. From the earthing of these two non-current carrying parts of the electrical system earthing can be classified into two types. Neutral Earthing Equipment Earthing. Neutral Earthing In neutral earthing, the neutral of the system is directly connected to earth by the help of the GI wire. The neutral earthing is also called the system earthing. Such type of earthing is mostly provided to the system which has star winding. For example, the neutral earthing is provided in the generator, transformer, motor etc. Equipment  Earthing Such type of earthing is provided to the electrical equipment. The non-current carrying part of […]

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Lightning arrestors, its features and specifications

A lightning arrester is a device used to protect the insulation and conductors of a system from the damaging effects of lightning. A lightning protection system’s purpose is to ensure safety to a building and its occupants if lightning happens to hit it directly, a task accomplished by providing a good, safe path to ground for the lightning to follow. The lightning arrester is located close to the equipment that is to be protected (on the roof near the PV power plant for example). They are usually connected between phase and ground in an AC system and pole and ground in case of the DC system. Components of a lightning protection system A lightning protection system is composed of three main components as mentioned in the below image: Rods or Lightning Rods or Air Terminal– The small, vertical protrusions designed to act as the ‘terminal’ for a lightning discharge. Rods can be found in different shapes, sizes and designs. Most are topped with a tall, pointed needle or a smooth, polished sphere. Conductor Cables – Heavy cables that carry lightning current from the rods to the ground. Cables are run along the tops and around the edges of roofs, then down one or more corners of a building to the ground rod(s). Ground Rods – Long, thick, heavy rods buried deep into the earth around a protected structure. The conductor cables are connected to these rods to complete a safe path for a lightning discharge around a structure. Lighting protection, standards […]

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