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    Advantages of Off Grid Solar Home System


  • Clean, Safe and reliable, No noise, No pollution

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  • Stable output to protect your appliance

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    Solar Home System

    600W Off Grid Solar Home System

    SUNVIS 600W solar home system is the smallest off-grid solar system, it contains solar panel, solar controller, solar inverter and battery. It's cheap and powerful. It can power your TV, fan, lighting and more.

    Main tech data:

    Solar Panel:1pc 100W Solar Panel

    Solar Controller: 1pc 10A/12V PWM Solar Controller

    Solar Inverter: 1pc 600W modified sine wave inverter

    Solar Battery: 1pc 12V 55AH Lead Acid Battery

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    1000W Off Grid Solar Home System

    SUNVIS 1000W Solar Home System uses MPPT solar controller to increase solar power generation by 20%. Save your money on solar panels. It is a sustainable, reliable and cost-effective solution that will meet your household needs.

    Main tech data:

    Solar Panel:2pc 200W Solar Panel

    Solar Inverter: 1pc 1000W Solar Hybrid Inverter

    Solar Battery: 2pc 12V 100AH Lead Acid Battery

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    3000W Off Grid Solar Home System

    SUNVIS manufactures and supplies solar systems of all wattages, and the 3KW off grid solar home system is the best seller. It meets the electrical needs of most homes. It will power your TV, Light bulbs, Fan, Fridge and water pumps.

    Main tech data:

    Solar Panel:4pc 200W Solar Panel

    Solar Inverter: 1pc 3000W Solar Hybrid Inverter

    Solar Battery: 4pc 12V 100AH Lead Acid Battery

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    5000W Off Grid Solar Home System

    SUNVIS 5000W solar home system adopts low frequency solar inverter with built in MPPT Solar Controller, This 5KW Solar system is built-in stabilizer with AVR function, it gives stable AC220V output to protect your appliances from shocks.

    Main tech data:

    Solar Panel:8pcs 200W Solar Panel

    Solar Inverter: 1pc 5000W Solar Hybrid Inverter

    Solar Battery: 4pc 12V 200AH Lead Acid Battery

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    Why Choose SUNVIS Off Grid Solar Home System?

    How to Build an Off-grid Solar System:
    Off-grid Solar System Design Guide

    Chapter 1: Off-grid Solar Home Systems Introduction


    Independent solar power systems are the large scale application of Stand-alone photovoltaic systems. Its main feature is the centralized power supply.

    For example, you can install an independent solar power system in a village which is a few dozen households and located in a remote area without grid power supply. It can offer electricity for the whole village. The power supply in this way is convenient to manage and operate.

    A household Off-grid Solar Home System, on the other hand, uses a decentralized power supply to provide electricity. If a village needs to install a household off-grid Solar Home System, each house needs to install a separated solar home system.

    Compared with the independent solar power system, the standalone off-grid solar home system is smaller in components size, but the basic structure of the photovoltaic system is identical.

    There are two types of off-grid solar home system: DC Portable Solar Home System and AC Off-grid Solar Home System.

    Independent Solar Home System

    Chapter 2: Off-grid Solar Home System Components and Working Principles

    2.1 Off Grid Solar System Packages

    The main components are as follows

    (1) Photovoltaic Modules and Stands

    (2) Solar controller

    (3) Batteries

    (4) Off-grid inverters

    (5) System lightning protection and grounding devices

    (6) Connection cables and protective materials for the system

    solar power system for homes

    2.2 Function and Role of Each Solar System Components

    The off-grid solar home system consists of solar panel, controller, battery, inverter, load and other components. The solar modules and batteries are for the power supply part; controller and inverter are for the control and protection part; the loads are for the system terminal.

    (1). Solar panels.

    Solar panels are a core part of a solar home power system that converts solar energy into the DC electricity. The output DC power is stored in the battery. The solar panel is one of the most important components of the solar home power system; its conversion rate and service life will directly determine the whole system quality and cost. Solar Panel production should be according to IEC:1215:1993 standard, using 36 or 72 pieces solar cell are connected in series or parallel to get 18V and 36V modules. The modules can be used in a variety of household photovoltaic systems, portable solar home system, solar street light, independent photovoltaic power plants and grid-connected photovoltaic power plants.

    MONO AND POLY Solar Panel

    (2). Solar controller.

    The function of the solar controller is to control the operation of the entire system and to protect the battery from over-charging and over-discharging. In places with big temperature differences, qualified controllers should also have the function of temperature compensation.

    MPPT Solar Controller

    (3). Battery

    There are different batteries for the solar system, Lead Acid Battery, Lithium Battery and LiFePO4 Battery; generally, lead-acid batteries are for big solar home systems, lithium batteries and LiFePO4 Batteries are for small portable solar systems. The function of the off-grid battery is to store the electrical energy generated by the solar panels when there is sunlight, and release it when needed. The quality and cost of the batteries can also have a direct impact on the quality and cost of the entire system.

    off grid solar battery

    (4). Off-grid inverters

    In many cases, there will require AC220V or AC110V AC power supply. But the direct output of the solar system is generally DC 12V, 24V, D48V, 110V DC, 220V. If you need to provide power for AC220V/AC110V appliances, it is necessary to convert DC power to AC power; hence It will need a DC-AC inverter.

    There are three types inverter: Square Solar Inverter, Modified Sine Wave Inverter and Pure Sine Wave Inverter.

    Commonly Modified Sine Waver Inverter is for off-grid solar system from small home less than 1000W, and Pure Sine Wave Inverter for big off-grid Solar Home System, such as 3KW and 5KW off grid solar system.

    solar inverter

    2.3 Schematic Diagram of Off-grid System Working Principles

    solar home system works principle

    Chapter 3: Off-grid Solar System Design Process-DIY Your Own Solar Home System

    3.1. Solar Home System Project Background

    Taking into account the average electricity consumption throughout the year, this off-grid Solar Home System is designed as a year-round balanced power generation system, so that we can figure out the PV module array installation tiles and other parameters.

    This solar home system will use an off-grid design, and the solar power is stored in the off-grid solar battery through the solar controller, and then connected to an off-grid inverter, which converts DC power to AC power for use by AC loads.

    average power consumption

    3.2. Basic Information and Specifications for each Single Component

    (1). Number of Autonomy Days in Rainy Days: 4 days

    (2). Load Type: AC220V Appliance

    (3). System Voltage: DC48V

    (4). Solar Panel: 320W/24V Mono

    (5). DOD of Solar Battery: 50%

    (6). Solar Battery Capacity: 12V 220AH/pc

    3.3. Off-grid Solar Batteries Design and Selection

    Battery capacity calculations depend on daily system power consumption, Autonomy days, Solar Inverter Efficiency and Solar Battery DOD. The choice of battery capacity is one of the critical issues in a home solar PV system. It is the most costly part in the off-grid solar home system, so It is very important to size the reasonable battery capacity.

    Daily Power Consumption

    According to the power consumption in the above chart, the average daily electricity consumption is 3526wh, and when calculating the average daily load consumption, we should consider the Solar Inverter efficiency. Usually, the solar inverter efficiency is 90%(you can check this from the inverter data).

    Average daily load (AH) = Daily Power Consumption / Inverter Efficiency / System Voltage = 3526WH/0.9/48V =81.6AH

    Number of Batteries in Parallel = (Average Daily Load * Days of Autonomy / Battery DOD) / Battery Capacity = 81.6AH*4/0.5/220AH = 2.97 ≈3

    Number of Batteries in Series = System Voltage / Battery Voltage = 48V/12V = 4

    Total Number of Batteries = Number of Batteries in Parallel * Number of Batteries in Series = 3*4 = 12

    off grid solar battery data

    3.4. Solar Panel Design and Selection

    (1) Design and Calculate the Solar Array Tiles

    The solar panel installation tile in horizontal depends mainly on the Latitude of the PV system and the requirements for the year-round energy distribution. You can work out the solar panel installation tilt angle in the following way.

    Latitude 0-25°: Tilt angle equal to Latitude

    Latitude 26-40°: Tilt angle equal to Latitude plus 5-10°.

    (2)Solar Panel Specification

    We will use 320W monocrystalline solar panel as monomer modules for the off-grid PV, with the following parameters

    320W Solar Panel Specification

    (3) Solar Panel Selection and Parameters

    Peak Current of PV Arrays=Average Daily Load/Battery Efficiency/Peak Solar Hours =81.6/0.8/4 = 25.5

    Number of PV Modules Connected in Parallel=PV grid peak current / PV module peak current = 25.5/8.56 = 2.97 ≈ 3

    Number of PV Modules in Series=DC system voltage / rated voltage of PV module = 48/24 = 2

    Total Number of PV Modules = Number of PV Modules Connected in Parallel * Number of PV Modules in Series = 3*2=6

    3.5. Off-grid Inverter Design and Selection

    For home solar power systems, it is necessary to have an AC output, so we need to install an inverter to convert DC to AC. The Off-grid inverter output waveform and frequency should meet the corresponding technical requirements; besides, the solar inverter must be equipped with short-circuit, overvoltage, Low voltage Protection Features.

    Solutions:

    (1). AC output power: according to data in the above chart, the total power of the appliance is 3712W. Based on a 60% simultaneous usage rate, the total appliance's power is 3712*60%=2227W, so the minimum inverter output power is no less than 2227W.

    (2). Battery DC Input Voltage: battery system voltage is DC48V

    (3). Output Voltage and Frequency: all electrical appliances are AC220V, 50HZ, so the inverter voltage should be AC220V/50HZ

    (4). Surge Capacity: taking into account the surge requirements of the load, multiply the peak power by three to obtain an estimated surge power of 6,681W. Note: this value is just according to experience.

    (5). Output Waveform: consider the appliance types; it needs a Pure Sine Wave Inverter.

    So, according to the inverter datasheet, you should use 4000W/AC220V, DC48V sine wave inverter. The parameters are as follows. Surge power can meet the requirements of electrical appliances.

    3.6. Solar Controller Design and Selection

    Solar Controller as an important part of the photovoltaic power generation system, the charging and discharging protection of the battery will directly affect the battery's lifetime, which will also affect the stability of the whole system. The controller is also required to have the following functions: high voltage disconnect and resume, low voltage warning and resume, low voltage disconnect and resume, short circuit protection. Anti-reverse charging protection and temperature compensation.

    Controller Input Current>Solar Panel Short-circuit Current*number of Parallel Modules*1.25*1.25=9.05*3*1.25* 1.25 = 42.37A Therefore, you should use a 50A/48V solar controller.

    3.7. AC/DC Circuit Breakers Selection

    If this system does not use a PV Combiner box, then you should install a unique DC Circuit Breaker between the solar array and controller. It is often misunderstood that circuit breakers and fuses are used to protect equipment from damage.

    In reality, however, their primary task is to prevent the wires from overheating and causing a fire.

    To achieve this, when the system is operating at a safe current, the DC Circuit Breaker or Fuse size must be less than or equal to cable current-carrying capacity.

    Circuit breakers or fuses have the following standard ratings: 1 to 15A in 1A increments. 15,20,25,30,35,40,45,50,60,70,80,90,100,110,125,150, etc.

    If the selected cable rated current is within this range, then select the closest value of the DC Current Breaker (higher than the cable rated current).

    Because the current from the solar panel to the controller and the current from the controller to the battery is the same, It is 42.37A, so you should choose a 50A circuit breaker.

    PV Circuit Breaker

    3.8. PV Cable Design and Selection

    For the wires used to connect the solar PV panels to the solar controller or solar battery, use the short-circuit current of the PV module multiplied by the numbers of PV modules connected in parallel.

    For the wires used to connect the battery to the inverter or DC load, use the total load current. After calculating the total current, multiply it by 125%, so that the current flowing through the wires will not exceed 80% of the cable rated current. This safety estimate should be made for all connected wires in the PV system.

    However, according to experience, we need to multiply it by an additional safety factor(125%) after figuring out the current between the PV Array and the battery, this will be used to cope with the extra current generated on the solar panels after strong sunshine.

    (1) DC side.

    Between photovoltaic array and controller: using 10MM copper wire, withstand current range: 50A-65A.

    Between the controller and the battery: using 10MM copper wire, withstand the current range: 50A-65A

    Between the battery and inverter: 10MM copper wire, withstand current range: 50A-65A

    (2) AC terminal

    Between the inverter and AC circuit breaker: using 10MM copper wire, withstand current range: 50A-65A

    Between the inverter and the AC loader: the use of 10MM copper wire, withstand the current range: 50A-65A

    3.9. Solar Panel Mounting Rails Design

    As the off-grid solar home system is installed on the flat roof, the solar module array bracket adopts the flat roof rail bracket with a tilt angle of 30 degrees.

    Solar panel mounting bracket

    It seems it is a complicated process to design your own off grid solar home system, but If you are interested in the solar home system design, we have an off grid solar system sizing calculator available, you only need to fill in the blank, the result will come out immediately.

    Download Off Grid Solar System Sizing Calculator

    Chapter 4: Regular Maintenance of Solar Home Systems

    Preventative maintenance is the best repair, so you should maintain your standalone PV system regularly. In this way, you can detect and deal with small problems before they become big problems.

    Even if the system was recently installed and is working correctly, it is time to start overhauling the system.

    Most inspections can be done with a voltmeter, ammeter and some common sense. Regular inspections should do the following checks.

    Maintenance of Solar Panels and Rails.

    Regular cleaning

    Wipe the surface of the solar module with a dry or damp soft clean cloth and not allowed to use caustic solvents or hard objects.

    Inspect regularly

    Adjust or replace immediately if any of the following problems are found

    1. Glass shattering in solar panels, scorched back sheets, or visible colour changes

    2. Solar Panel junction boxes are deformed, distorted, cracked or burnt, and terminals do not connect well.

    3. All bolts, welds and bracket connections should be stable and reliable.

    Maintenance of the battery

    First, You can check the voltages of each battery with a load on, and then compare those voltages with the average voltage of all the battery. If one battery is 0.05V off from the others, it may have a problem. Monitor the performance of that battery to see if it needs to be replaced

    Maintenance of inverters

    (1). The structure of the inverter and electrical connections remain intact, does not allow the presence of rust and dust. The heat dissipation should be good; there should not be any large vibration and unusual noise when the inverter is on operating.

    (2). The warning signs on the inverter should be complete

    (3). Inverter transformer cooling fan to start and stop function according to the temperature should be normal. Cooling fan operation, there should not be any large vibration or abnormal noise when the inverter is operating. If abnormal, You should switch off the inverter and do the inspection accordingly.

    Cable maintenance

    (1). The cable should not be run under overload; the cable insulation should not appear bulging, cracking and other phenomena.

    (2). Cable and the equipment connections should be firm, cannot be loose

    Chapter 5: Conclusion

    SUNVIS SOLAR has been a manufacturer and supplier of solar home systems for over 17 years and exports its off-grid Solar Home Systems all over the world.

    If you are looking for a qualified best off-grid solar home system supplier or manufacturer for your next project, please contact us.

    You just tell us your needs, and we'll offer you complete solar power kit for homes. And also we can offer one-stop solar solution service for your off-grid solar home system project.

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