Earthing refers to a safety system designed to protect electrical wires and components from damage caused by sudden electrical power surges. 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. Earthing system is important because it provides: – Safety for humans from electric shocks; – Protects the installation and equipment itself from any damage; – Safety from atmospheric electricity (lightning) etc.
Safety should always be a priority during any installation. Although, most of the safety aspects and technical standards are followed by the manufactures and installers of the rooftop solar power plants, there are a few general safety rules that one should know to minimize risk in a solar power plant before, during and post-installation. Pre-installation PV module installation area/roof must be thoroughly inspected by the installer for possible electrical, chemical, fire etc. hazards before installation The roof where the solar power plant is being installed should be strong enough to support the weight of the plant to avoid future damage Never install a PV power plant near chimneys or flame outlets that could damage the PV modules PV module should be designed with safe lines (wherever needed) so that the maintenance and cleaning of the PV modules can be done safely During installation PV modules or other PV components should not be installed during bad weather. PV modules can be blown around by the wind or a storm which can result in you falling or damage to the PV system and nearby objects and even injury to humans Always ensure that extreme safety precautions (including body harnesses, lifelines and safety nets) are used by the installer to prevent slipping, falling and causing injury when working, especially at height Make sure the area underneath the installed PV modules is clean, clear and free of foreign objects which prevents from water logging Make sure your entire solar power plant is properly and […]
A module mounting structure (MMS) is the supporting structure that holds the PV modules to the roof or ground and provides the desired tilt angle for a maximum generation it is designed for. The type of MMS design is based on the surface of installation i.e. Iron, RCC or Asbestos roof. Generally, module mounting structures are of three types: Hot Dip Galvanized Iron (GI) Aluminium Mild Steel (MS) Various rigorous structural analysis and tests for protection against wind and also for the mechanical strength of the MMS to guarantee the safety and stability of the mounting structures are required to be conducted before installation.
Solar PV modules can be installed on almost all kinds of rooftops. The complexities involved in installing a PV module may differ with different rooftops, type of roof construction and roof strength. Therefore there are different PV module mounting structures for metal roofs and flat concrete roofs. Some of the examples of commonly used mounting structures based on the roof type are mentioned below. Flat concrete roofs (example RCC) Concrete roofs are in general the easiest way to install a solar power plant as the access for installation and later operations and maintenance if very easy. Depending on the roof design and shadow-free area the common type of module mounting structures for concrete roofs are highlighted below: 1. Low elevation ballast structures This type of structures are designed for flat roofs with limited load capacity and where there are no shadow issues. The design of the system includes a windshield (sloped wind deflector) that seals the system and reduces the suction force of the wind on the PV modules making the installation stable under high wind load and prevents the frame from overturning/lifting. Typically such mounting structures have a tilt angle of not more than 15 degrees. 2. Elevated ballast structure This type of structures are advised for flat RCC roofs which have shading issues. These structures can be designed for high ground clearance and can easily combat heavy wind loads. These structures are also designed for installation with penetration to the roof; however, it is not recommended. Instead ballast-based […]
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. There are three major types of PV modules. Mono-crystalline Poly-crystalline Thin-film Each solar PV module type has its own unique features. These PV modules also vary based on how they are manufactured, their appearance, performance, costs, etc.
Solar photovoltaics are made with a number of parts, the most important of which are the solar cells which are connected and sandwiched between glass and metal. Major components of a PV module are: Module Frame Glass Encapsulant Back Sheet Backsheet is a film of that protects the solar cells from severe environmental conditions. A solar back sheet is the last layer at the bottom of the solar PV module and is typically made of a polymer or a combination of polymers. Junction Box
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 have better efficiency and power capacity.
Solar panels generate electricity using the radiation emitted by the sun. When a group of such solar panels along with associated components are installed on the top (roof) of a building, it is known as a rooftop solar photovoltaic power plant. Solar panels convert sunlight into electricity. They are mounted using customised mounting structures fixed to the roof. The electricity (Direct Current) generated by the solar panels is converted into Alternating Current (AC) using an inverter. If electricity is required when there isn’t enough sunlight for the panels to generate electricity (such as at night) or in case of power outages, a battery backup is required and can be added to the system.
Reduction of energy bills – Installing solar power plant can help to save substantial amount of money on electricity bills. Per unit cost of energy generated from the solar plant is comparatively cheaper to energy purchased from the utility. Use of underutilized roof area – Installing solar plant on the roof is most effective way to utilize roof. This not only increases the value of the home but also offers multiple financial benefits. Participation in building modern Indian power system – Installing solar power plants supports creation of distributed power generation network and reduces need for extensive use of fossil fuels. Reduce power losses – The energy can be produced though solar power plant on your own roof and can be consumed within your building, which limits transmission losses. Renewable energy source – Unlike fossil fuels and natural gas, the sun is a source of energy that is renewable. Going solar reduces our dependence on the fossil fuels. Shrink your carbon footprint – Going solar reduces the CO2 emissions, the leading cause of climate change and global warming.
A grid-tied solar PV system is a power plant that is connected to the utility grid and uses electricity from both the solar system and the utility grid. These systems do not have to meet all of the electricity demands of the consumer electrical load. If needed, the load can draw energy from the grid at times (such as on cloudy days or at night) when the system is not generating electricity as per demand. Likewise, if energy generated is more than required, the surplus power generated can be exported to the utility grid. These systems are connected to the main utility grid supply panel of the consumer facility and are designed to generate power when the utility grid is available (figure). In case of grid failure (blackout) or fluctuation outside permissible limits, the system stops working immediately and isolates itself from the grid. These systems are cheaper than battery-based solar power systems as there is no battery backup included, hence reducing the overall cost of the system. The working of a grid-tied solar PV system is explained in the video, below. Video by: MaXolar Energy (YouTube Channel)