1. Types of Grid-Tied Solar Power Systems
Grid-tied solar power systems are classified into two main types based on their energy storage features:
For Grid-Tied Systems Without Storage:
System components include:
- Solar panels (photovoltaic panels)
- Solar power electrical cabinet
- Grid-tied inverter
- Accessories and electric cables
Operating principle:
- Energy from sunlight is converted into direct current (DC) by the solar panels.
- DC is converted into alternating current (AC) by the inverter to connect to the grid.
- The system prioritizes solar energy usage, only drawing power from the grid when necessary.
This system operates alongside the power grid, with solar energy always taking priority. If there is a power outage, the system will cease operation to prevent feeding electricity into the grid, ensuring the safety of grid technicians.
For Grid-Tied Systems With Storage:
System components nclude:
- Solar panels (photovoltaic panels)
- Charge controller
- Storage batteries (usually lithium)
- Hybrid inverter
- Other accessories
Operating rinciple:
- Solar panels absorb sunlight and convert it into direct current (DC).
- The charge controller manages the current before storing it in the batteries.
- Excess electricity, after meeting usage needs, is stored for later use.
Learn more about grid-tied solar power systems at:
2. Installing Grid-Tied Solar Power Systems Process
Despite differences in system structures, the basic installation process for grid-tied systems includes the following main steps:
1. Preparation and Installation of Solar Panels on the Roof
- Identify the optimal location, usually on the roof or an area with strong sunlight.
- Set up sturdy mounting structures to withstand impacts from wind or storms.
- Install solar panels in series, ensuring proper spacing to enhance operational efficiency.
Initial step in installing a grid-tied solar power ystem
2. Installing the Inverter and Battery Backup (If Applicable)
Identify the location for installing the inverter and battery backup. Ensure both devices are installed indoors or under a covered area to maintain electrical safety.
3. Wiring the Electrical System
- Connect the wires between the solar panels, ensuring the voltage of one string is checked before parallel connections.
- Wire the solar panels to the inverter and battery backup (if applicable).
How to Install Solar Panels (Photovoltaic Panels)
Series Connection Method for Solar Panels
Connect the negative terminal of one panel to the positive terminal of another panel to increase the voltage.
Example:
Using this method, even if the solar panels differ in type and capacity but have the same current rating, they can be connected in series. When connected, the system generates 63 W of power with a voltage of 21 V and a current of 3 A. The output current remains constant at 3 A, while the voltage increases to 21 V (5 + 7 + 9).
Series connection method for solar anels
Parallel connection method for solar panels
This method involves connecting the same terminals (positive to positive, negative to negative) of the solar panels to increase power output.
In the situation that all solar panels are of the same type and capacity, using three panels rated at 6 V and 3 A each in parallel connection:
- The output voltage remains constant at 6 V.
- The current increases to 9.0 A (3 + 3 + 3).
- The total power output reaches 54 W.
Parallel connection method for solar panels
Mixed Solar Panel Connection Method
This method combines both series and parallel connections to increase both voltage and power output. It is particularly suitable for medium and large-scale solar power systems.
How to Connect a Solar Inverter
After the solar panels are connected, follow these steps to link the inverter with the solar power system and storage battery.
Bước 1: Connect the inverter to the solar panel rray, ensure proper polarity by connecting the positive terminal (+) and negative terminal (-) correctly.
Bước 2: Connect the inverter to the electrical cabinet, adapt the connection based on whether it is a single-phase or three-phase system.
Bước 3: Connect the inverter to the storage battery (if applicable), esure correct polarity when linking the inverter to the storage battery.
Bước 4: Perform a thorough check of all connections to ensure safety and stable operation.
4. System Inspection and Trial Operation
- Conduct a comprehensive system check to identify and resolve any technical issues.
- Perform trial operation to assess efficiency and address any potential problems.
Key Considerations When Installing Grid-Tied Solar Power Systems
- Roof Orientation and Tilt Angle: Position solar panels facing South or Southeast to maximize sunlight absorption.
- Avoid Shading: Ensure the installation area is free from obstructions such as trees or buildings.
- Regular Maintenance: Clean the surface of solar panels periodically to maintain high performance.
Key considerations when installing grid-tied solar power systems
Quy Tắc An Toàn Khi Lắp Đặt Hệ Thống Điện Mặt Trời
When installing a solar power system yourself, following safety rules is crucial to protect your health and property. Below are fundamental principles to keep in mind:
1. Stop Work During Adverse Weather Conditions
First, always halt installation during bad weather, especially heavy rain or strong winds. Working on rooftops during strong winds can compromise balance and risk damage to the system. Besides, rain and high humidity increase the chance of slips and accidents involving electrical tools.
2. Avoid Putting Pressure on Solar Panels
Do not sit or stand on solar panels to prevent breakage or damage to the equipment. You should avoid placing any objects on the solar panels, as it can scratch the surface, reduce sunlight absorption, and lower efficiency. You ought to refrain from actions that could lead to injury or the risk of electric shock.
3. Inspect the Roof and Installation Area
Before starting the installation, make sure that the roof or installation area is sturdy enough to support the weight of the solar panels. If your roof is old or damaged, it should be thoroughly inspected to prevent water leakage or damage. Additionally, ensure that the installation area is clean, well-ventilated, and free of obstructions.
4. Adhere to Safety Measures During Installation
Make sure to wear full protective gear such as slip-resistant shoes, insulating gloves, helmets, and other safety equipment like safety harnesses. Ensure that you are not working alone, and always have at least one companion to handle emergency situations. Before starting, thoroughly check the tools to ensure they are functioning properly.
Additionally, avoid wearing metal jewelry when working near the solar power system to prevent the risk of electric shock. Areas with flammable gases or corrosive environments should also be avoided to ensure maximum safety during installation.