MultEE Physics

  Why do we need sizing? To determine the size and capacity of the PV modules, battery, and other Balance of System components. To determine the configuration of batteries and PV modules. Types of PV System PV systems can be broadly classified into three categories: I. II. III. List of Equipment & materials used in the sizing of a PV system PV Modules (Solar Panels) DC Cables DCDB/SJB/AJB ACDB Cable Tray/Conduit Inverter Isolators AC Cables Isolation Transformer (Where Required) Earthing Cable/Earthing Strip Earthing Rods Lightening Arrestor Generation and Net Meter(Bidirectional Meter) System Sizing Step 1: PV System Capacity While sizing the PV system, we mean to manipulate the capacities of generation to the AC load where we specify: DC Capacity of the PV plant AC Capacity of the Inverter output Battery Capacity and the total size as per backup power Capacity is based on: Energy requirement Space limitation Budget limitation Step 2: Specific Equipment  Specifications Wh...

  Design Methodology PV systems are designed to meet the demand load as per the requirement. Configuration selections are the most considerable procedure in designing a solar PV plant.  Selection of the quality of a component to maintain project cost within the budget. PV system sizing involves the determination of the sizing and capacity of various components like PV panels, batteries, etc. Mainly two approaches are used in a PV system design depending upon the level of details used in component sizing Approximate sizing Precise Sizing Design Steps PV system design proceeds in the reverse direction of energy flow Step 1: Load estimation Step 2: Inverter sizing Step 3: Battery sizing Step 4: Solar radiation estimation Step 5: PV panel sizing Load Estimation Following parameters are considered while estimating load requirement Type of load (AC or DC) Number of Loads The power rating of each load Hours of operation Energy requirement per day(kWh/day) Selection of Components To s...

  During daylight, an array has more voltage potential than the battery, so current flows from the array into the battery. But at night, the module potential drops to zero, and the battery will be discharged all night, backward through the module. This would not be harmful to the module but would result in a loss of precious energy from the battery bank. Diodes placed in the circuit between the module and the battery can block any nighttime leakage. Blocking diodes (series or isolation diodes) conduct current during normal system operation and are placed in series with a module/string/array. Its main purpose is to prevent current from flowing backward through the modules at night and prevent current from flowing into a faulty parallel string.

  When a cell in the photovoltaic module is damaged or a part of the module is shaded, the shaded cells will not be able to produce as much current as the un-shaded cells. Since all the cells are connected in series, the same amount of current will flow through the damaged or shaded cell that will now act as resistance and become hot and energy generated in the module will be lost. This is known as a ‘hotspot’ phenomenon. This can be avoided by using a bypass diode in the module parallel to the output terminal as shown in the diagram below. If one cell is damaged then the rest of the array can force current through it, producing a significant temperature rise in the cell and leading to further damage. This phenomenon is called a “hot spot” formation. As per IEC 62548, a PV system with voltages above 50V DC should include a bypass diode.

 Hybrid PV Systems A Hybrid PV system is considered a better solution to meet the increasing energy demands. Hybrid PV systems mean a combination of both PV plant and grid utility with a battery pack taken under consideration for energy demand.  Renewable energy sources depend on the weather conditions i.e., when the sun’s radiation is good then the plant generation would also be high. During bad weather i.e., cloudy days with very less solar radiation, the plant generation will be low. In this case, we need to switch to utility power to meet the energy demands. Therefore, the integration of renewable energy sources provides better performance and reliable output than standalone systems during any cycle of the power generation system. The hybrid energy system aims to combine solar PV energy connected to the grid, with controlling techniques for maximum power generation. Both battery bank and grid availability are the main considerations for a Hybrid PV system so that to m...

  In aOff Grid Solar PV System, the grid is absent. The system-generated electricity is used for home consumption and to charge the battery bank. Power generated from the rooftop system is stored in a battery bank. The stored power is then fed to load as and when required. Both types of appliances AC and DC can be connected to this system. The inverters are smart and can optionally use PV plant power. These systems offer complete autonomy and independence from the grid and power companies- meaning never has an electricity bill. Energy storing arrangements like battery banks are the main considerations for this system. How a Stand Alone PV system works Bright sunshine on Solar PV panels. These panels generate electricity which is used at home and to charge batteries. The batteries allow for the storage of electricity for use at night or during times of low generation on cloudy days.  Solar PV panels mounted on the roof capture energy from the sun and convert this energy into DC...

 The solar  power sector in India has emerged as an upcoming section in the last few years. It supports the government’s agenda of sustainable growth, while, emerging as an integral part of the solution to meet the nation’s energy needs and an essential player in energy security. A   grid-connected photovoltaic power   system is an electricity-generating solar PV system that is connected to the utility grid. This system requires No energy storing system like battery bank arrangements. The grid-connected PV system is also called an On-grid PV system OR Grid-Tied PV System. How a Grid-connected Solar PV system works The sun shines on the solar panels generating DC electricity. The DC electricity is fed into a solar inverter that converts it to AC electricity. The AC electricity is used for appliances at home. Surplus electricity is fed back into the main grid with a track record of Net-Metering ...