Solar String Inverters (String Inverter) and Micro Inverters (Micro Inverter) are two common inverter types used in solar PV systems, which are significantly different in design, application scenarios, and advantages and disadvantages. Below is a detailed comparison of these two types of inverters:
What is Solar String Inverter
String connection: Multiple solar panels are connected in series to form a “string”, similar to connecting multiple cells together to form a battery bank.
Centralized conversion: The power from these panels connected in series is centralized and sent to an inverter. This inverter converts the DC power generated by all these panels into AC power.
Core Function: The main function of the inverter is to convert the DC power generated by the solar panels into the AC power that we use in our daily lives, so that it can be supplied directly to our homes or fed to the grid.
Advantages of Solar String Inverters
- Lower cost: Since one string inverter can be connected to multiple solar panels, the total system cost is lower.
- Easy maintenance: Centralized management and maintenance reduces system complexity.
- High efficiency: under ideal conditions (all panels receive the same sunlight and temperature), string inverters are more efficient.
Disadvantages of Solar String Inverters
- Single point of failure risk: If one of the solar panels fails, it can affect the performance of the entire string.
- Highly affected by shading: If one panel is shaded, the output power of the entire string can drop significantly.
- Less flexible: System design and installation need to take into account the consistency of orientation and angle of all panels.
What is micro inverter
A microinverter is a small device mounted behind each solar panel whose main function is to independently convert the direct current (DC) generated by each panel into alternating current (AC). Here is a brief explanation of a microinverter:
Independent conversion function: Each solar panel has its own inverter, and this inverter independently converts the DC power from that panel to AC power. This means that each panel works independently and is not affected by other panels.
Advantages of micro inverter
- INDEPENDENT OPERATION: Each panel operates independently from shadows or malfunctions in other panels, improving the overall reliability and performance of the system.
- Optimized Output: Maximum Power Point Tracking (MPPT) is performed independently for each panel, ensuring that each panel operates at its optimum.
- High flexibility: Flexible installation allows panels to be freely arranged according to the shape and angle of the roof.
- Easy to monitor: often equipped with a more detailed monitoring system that allows real-time viewing of each panel’s performance.
Disadvantages of micro inverter
- Higher cost: Higher initial investment due to the need to equip each panel with an inverter.
- Complicated maintenance: decentralized installation of inverters makes troubleshooting and repairs potentially more complicated.
Applications of solar String Inverter and micro inverter
String inverters: suitable for large roof areas and consistent sunlight conditions, especially for commercial and large-scale solar power plants. Microinverter: for small residential solar systems with complex roof shapes, partial shading or where output needs to be maximized.
Summarize
The choice of inverter should be based on the needs, budget and installation conditions of the specific project. String inverters are low cost and easy to maintain, but are more affected by shadows; microinverters are more costly but stable and flexible. Understanding the advantages and disadvantages of both and the application scenarios will help make the optimal decision.
