Best Solar Inverter Review- How to judge if an inverter is good or not?

Best Solar Inverter Review - How to judge if an inverter is good or not?

Which solar inverter brand is the best inverter? How to judge if an inverter is good or not?

The answers are: the insight into consumer demand, simple and friendly human-machine interface, The technical compliance of grid regulators, the convenience of installation and attention to safety with performance.

In one word, quality and performance both together to support the inverter to be the best inverter brand.

  1. DC Input Isc and Imp

Let’s compare the maximum short circuit current (Isc) and maximum input power current (Imp) of different brands.

The latest Australia Solar Installation Standard AS5033.2021 has been officially implemented on 19 May 2022, which requires that:

1.25×PV Panel Isc <=PCE(Inverter) DC input Isc

i.e. 1.25 times the PV string short-circuit should not exceed the maximum DC input short-circuit current of the inverter.

Taking into account the most popular model 415-watt solar panels - The mainstream PV panels maximum short circuit current (Isc) is around 14A and maximum power current (Imp) is around 13.5 A.

According to AS5033.2021, the ISC of inverters should not be lower than 17.5 A, and the Imp of inverters should not be lower than 13.5 A.

After some investigation and enquiry into the well-known inverter brands, Goodwe, Growatt, Sofar and Huawei - they cannot be used for 390 watt or 415-watt panels for solar installations because of the low ISC. Sungrow,Solis and Each Energy can use for 390 watt or 415 watts as all these brands have high ISC current. Especially Solis and Each Energy, that has 22A for ISC current, much higher than the state of the standard.

In terms of the Imp - For the Single-phase inverters between 3 to 6kw:

Fronius, Sungrow, Huawei, Goodwe and Sofar fail to perform as best efficiency due to low Imp.

SMA and Each Energy are good on Imp.

For the Three-phase inverters between 5 to 10kw:

SMA, Sungrow, Goodwe, Growatt, Huawei and Sofar fail to perform as best efficiency because of low Imp.

Fronius and Each Energy are good on Imp.

  1. Start up and Shut-down voltage

As we know, there are two factors will affect voltage. One is the irradiance, another is temperature. In the day time, unless the sun is completed blocked by the clouds, even the sunlight indirectly penetrates the solar panels, the voltage is still stable. However, as the rising of temperature, the voltage will decline. When temperature reaches 25℃ and rises to 40℃,the voltage will drop by 0.28% on average for each degree of rise.

So, the voltage starts up at 4-5am, rising to peak at 8am in the morning, and as temperature drop off at 3-4pm, the voltage will be rising to another peak, then drop off until zero around 9pm.

Regarding the start-up voltage: Solis and Each Energy inverters start working before 5 am in the morning in the summer months. With regards to the shut-down voltage: Solis and Each Energy inverters keep working until 9pm in the evening in the summer months.

The two brands we mentioned can generate 2 hours more than other inverters average generation.

However, in ancestrally experience, the Each Energy can work half or one hour more than Solis because Each Energy shut down voltage at 30 V, the Solis shut down voltage at 40V-50V.

This in turn means both Solis and Each Energy inverters generate more power and provide installers extra hours in time to commission and test the inverter in the evening after installation has been completed.

  1. Multi Mppt Number, Multi String Numbers

Here we briefly explain the role of the Mppt:

Mppt, Maximum Power Point Tracking (Mppt) system is an electrical system that enables photovoltaic panels to output more electric energy by adjusting the working state of electrical modules.

Put it in simple words, it is only with it that the electricity generated by the solar panel can be captured as much as possible into the inverter for use.

Each Mppt system can only track solar panels in one direction, so when your house has three roofs orientations, you need inverters with Three Mppts to ensure that the working efficiency of all facing solar panels is tracked by Mppts and the efficiency is maximized.

We found Fronius and Each Energy have multi Mppt number, multi string numbers which make their inverters more flexible than other brands

  1. Testing and Commissioning Method

Many inverter brands have only one way to test and commission, that is Wi-Fi. However, many houses are located in the country side with poor communication signals. The inverters with LCD and buttons are a second way to test and commission, these are preferred. Fronius and Each Energy have LCD and buttons, which are preferred and recommended.

  1. Wi-Fi connection

Each Energy use WIFI + Bluetooth in a two way to apply Wi-Fi configuration. This increases the Wi-Fi success connection rate to 99%+.

  1. Max Efficiency and EU efficiency

Higher efficiency means higher yield, here are the comparisons between different brands.

After specification comparison from the above 6 perspectives, we believe you have the answer to which solar inverter is the best brand.

1 Like