Home »Blog» Choosing the right inverter for high-power M10 (182mm) and G12 (210mm) photovoltaic modules

For decades, mainly due to technological progress and cost reduction, the size of silicon wafers used for solar modules has evolved from the early 125mm to the current standard M6 (166mm), M10 (182mm) and G12 (210mm)). What impact do these larger modules have on related equipment? What should be considered when designing a system with these modules? What are the effects of high-current components and inverters?

We study these so-called "high power" modules in more detail and compare them using actual operating conditions.

Features of M10 and G12 photovoltaic modules

Since the output current of a solar module is related to its area, the larger the area, the greater the output current. Look at the figure 1, the data sheet of the 530-550W M10 (182mm) solar module range, the output current of the module is less than 15A under normal working conditions; for high irradiance areas, under the condition of high ground reflectivity, 182mm silicon battery module It may reach 15A, but for G12 (210mm) modules, the current will exceed 15A, as shown in Figure 2.

Figure 1: M10 (182mm) photovoltaic panel data sheet

Figure 2: G12 (210mm) photovoltaic panel data sheet

The DC side of the inverter has certain restrictions on the current connected in series. For traditional string inverters, the maximum current of each string is 12.5A. In most application scenarios, standard M6 (166mm) solar modules operate under normal working conditions. The output current is less than 12.5A, and it is compatible with traditional inverters and M6 components.

The current of M10 and G12 modules is greater than 12.5A, so the risk of current limiting caused by incompatible inverters increases, especially when the irradiance exceeds 800W/m2. The output current of the string will exceed the allowable input current of the inverter, and the inverter cannot adapt to the input power, resulting in a loss of efficiency.

When designing a system with these types of modules, an inverter developed for use with high-power modules must be selected.

Solis inverter-compatible with high-power modules

Solis inverters have been upgraded from small houses to utility scales. The maximum MPPT current can reach 32A, meeting the needs of high-current photovoltaic modules.

For example, looking at the data sheet below, the maximum power of a Solis 3-phase 10kW inverter is. Input current is 2*16A or 16A per MPPT

Work scenario simulation-Solis and "other" inverters

For these two systems, we chose a 210mm module with a power of 550Wp; under the same external environment, run for 1 day to verify its adaptability.

In the first system, we used a Solis three-phase 10kW inverter with 16A string input current.

In the second system, we used a 10kW inverter from another manufacturer with a string input current of 12.5A.

After completing the comparison test, we derived the string current output data from the monitoring software.

Solis inverter with 16A input current

Using the inverter with 2*16A MPPT input current, the string current (green), voltage (blue) and power output (red) are as shown in the figure below.

It can be seen that under high irradiance, the photovoltaic module current exceeds 15A, which is close to 16.3A. Because the inverter is compatible, the string current is not limited, and the power generation is maximized.

Another inverter with 12.5A input current

Using an inverter with 12.5A MPPT input current, the string current (green), voltage (blue) and power output (red) are shown in the figure below.

In the same situation, with high irradiance, the photovoltaic module current reaches 16.3A. The string current is limited to 12.5A by the inverter. The power generation of the module is not maximized and is limited by the operating capacity of the inverter.

In the experiment, a 210mm G12 module was used, and the DC side installed capacity of a single inverter was 13.2kW. When using a 12.5A inverter, the loss caused by the current limit on the DC side of the inverter is 6.16kWh, which is equivalent to a power loss close to 14%.

When using the 16A input current inverter model, there will be no loss due to the inverter's DC side current limitation.

At the same time, the larger the input current of the inverter, the smaller the loss of overload and current limiting.

For the 210mm G12 module, there is considerable current-limiting power loss when using a 12.5A inverter.

It is more appropriate and wise to choose a single string 16A or install more inverters. Of course, you can also use an inverter with an MPPT input current exceeding 16A. For 182mm components, the current carrying capacity of the 16A input current inverter is more than sufficient.

Solis upgraded inverters with higher input current are compatible with all high-power and double-sided modules. Choosing Solis means that you will always maximize the power generation potential of high-power modules.

Solis is one of the world's largest and most experienced string inverter manufacturers, with a global service team network.

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