When choosing a solar power system, we are often faced with the question of whether a string inverter or a parallel arrangement of microinverters is better.
First we need to understand what the function of an inverter is to be able to analyze the advantages and disadvantages of these two types:
An inverter is an electronic device that converts direct current (DC) to alternating current (AC) and plays an indispensable role in harnessing solar energy to enable sustainable energy generation.
The most common types are the string inverter and the microinverter, a comparison will help to understand the differences more clearly:
Working principle:
The string inverter connects multiple solar modules in series, and the entire system can be made up of multiple groups of series solar modules connected in parallel. For example, the 12-panel solar system most commonly found in the Netherlands consists of 6 panels in a group, making two groups in total, which are again connected in parallel and do not affect each other. When there are different roof orientations, the series with different orientations are usually merged, and the groups of solar modules on different roofs are connected in parallel.
Microinverters, on the other hand, are each individual solar module as a separate group, all connected in parallel.
Differences:
String inverters are technically sophisticated, which gives them the advantage of cost savings and higher efficiency. They are cheaper than microinverters and have a long service life.
Compared to microinverters, string inverters are more compatible with different brands of solar panels, and due to the simpler system structure, the probability of failure is low. Even in the event of a failure, replacement is easy and repair costs are low.
However, if the performance of a single solar panel in a string inverter is poor, it will directly affect the performance of the entire array, while microinverters are less prone to shadows or failures and can continue to operate.
Microinverters are also more reassuring because they operate entirely under alternating current and there is no high voltage direct current. They offer greater flexibility when designing solar systems. For example, the power generation efficiency is higher when using microinverters when each solar panel is different in terms of orientation, angle and light area.
Songsolar has created a table of string inverters and micro inverters directly so you can compare them accurately. Check them out and make your decision!
feature |
String inverters |
Micro inverters |
Operating Principle |
Mainly converts DC to AC in series, eg, 12 panels in 6 groups, parallel |
Each solar panel's backside inverter converts current independently, in parallel |
Advantages |
- Mature technology, long lifespan - Low cost, affordable - Simple system, low probability of failure - Easier and faster installation - Easy troubleshooting - Simple wiring, less energy loss |
- High efficiency generation - Good performance under shade - Great flexibility in panel orientation and tilt - Easy monitoring, easy to expand |
Disadvantages |
- Susceptible to shading, dirt - Not suitable for system expansion - Entire system affected in case of failure - High voltage, risk of arc |
- Higher purchasing & installation costs - Complex installation, higher failure rate - Difficult to maintain and replace |