In response to a customer preference for its multiple Symo inverters over Agilo central inverters, Fronius has introduced the Eco 25/27 kW project inverters.

The Eco range comes with the usual SnapINverter features, such as wifi web monitoring and an integrated DC isolator.

SnapINverter Features

The Eco 25/27kW inverters come from the same SnapINverter family as the popular Symo range, and is akin to an economical version of the Symo. 

The Symo set a company benchmark when it came to power density, with 20 kW at only 43 kg (0.46kW/kg). The Fronius Eco, however, smashes this record with 27 kW at only 35 kg (0.77W/kg).

To achieve this density, the power control stage has been redesigned; the Symo has a buck-boost converter, whereas the Eco only has a buck converter. Consequently, the Eco inverter:

  • Can be installed on commercial sites (with maximum PV voltage of 1000V DC)
  • Would not be suitable for residential systems (you can use the Symo for three-phase residential)
  • Has a limited DC input voltage range
  • Has one maximum powerpoint tracker (MPPT)

This would typically save you 10 to 25 per cent in total system costs over a Symo installation – depending on system size – making the system more competitive than other European-made manufacturers with a similar sized 27 kW inverter.

Commercial design tips

To ensure your Fronius Eco commercial quote is as competitive as it can be, there are a few more features that can be taken advantage of to ensure there are no surprises for installation.  

String fusing and overvoltage protection

Like the Symo 10-20 kW inverters, Eco inverters feature an option to add overvoltage protection modules into the undercover, power connection area of the inverter. The Eco units also have inbuilt 6x double pole PV string fusing holders. That means there is no need to install separate string fusing and enclosures. 

String design

Most commercial PV arrays are mounted on large expanses of roof, where the whole array is mounted facing the same way. This is perfect for the Eco’s single MPPT. Keep in mind that all parallel strings must have the same number of panels in each string to keep the string voltages equal. 

The string voltages must also be high enough to fit in the MPP voltage window of the inverter.  Typically, the ECO inverters should have three to five strings of 23-24 panels in a series, if you are using a standard 60-cell PV panel. The Fronius Solar Configurator software offers a convenient way to check your string configuration. 


Finally, if you require flexibility in your string design, or just can’t mount the whole PV array facing the same way, then you could add one or more Symo to your multiple Eco inverter system. Like with all SnapINverters, multiple units can be daisy-chained on the communications line so all inverters can be monitored using one Datamanager card, which is only required in the first inverter. This ensures all your solar generation data is monitored online at the Fronius Solar.web portal.