FIMER-ABB UNO-DM Inverter – ESE Review


Jack Ayre

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In 2020 Italian company FIMER acquired the solar inverter business of Swiss engineering giant ABB. The highly-regarded range of inverters – formerly branded ABB – are now being sold by FIMER. Under the bonnet, however, the inverters are still the reliable ABB design, so potential customers can be reassured that the product is still a market leader.

ABB inverters, originally produced under the Power One Brand, steadily achieved a reputation as being solid and reliable mid-market products. Now they are made and marketed by FIMER.

The company has two different product lines: the UNO-DM string inverters and the PowerUNO hybrid inverter series. What is the difference? String inverters convert solar panel DC electricity into AC for use in the home or selling back to the grid. Hybrid inverters can do the same, but also charge batteries. This could be important: if you are planning battery storage in your system, or may upgrade in the future, you are better off paying more for a hybrid inverter, rather than purchasing a string inverter, then having to replace it with a hybrid in the future.

FIMER Company Overview:

FIMER became the fourth largest solar inverter supplier in the world with the acquisition of ABB’s inverter business. The company sells its products in 26 countries, employing over 1100 in their global workforce. The 2020 revenue was a respectable €148.4 M, making it a medium-sized player in the solar power technology marketplace.

The company was founded in 1942 and has been making solar inverters since 1983, so is very well established in the sector. Its products were originally aimed at large-scale solar arrays in industrial and commercial energy plants. Now that FIMER has residential inverters in its product offering, it has become a significant presence in the home renewable energy market.

The company highlights its continuous investment in R&D to develop innovative platforms and solutions in various green energy sectors. It has three research centres to actively pursue new technologies. The company has offices in over 20 countries worldwide, with partners in many other countries.


FIMER Inverter Specifications:

FIMER string inverters


1.2 to 6.0 kW

The UNO-DM-TL-PLUS-Q single-phase solar inverter family, with power ratings from 1.2 to 6.0 kW, is the leading-edge option for residential solar power arrays.

These units have an operating efficiency rate of 97% to 97.4%, which is in line with the industry standard and represents normal operating parameters for an inverter.

A flexible inverter system for all residential roof sizes

The innovative design builds on ABB’s core engineering, adding FIMER’s quality production into a

lightweight and compact inverter which is beneficial for installations with multiple orientations.

The inverters share the same compact footprint, ensuring the user will receive high performance with minimal space utilisation. The models are available with single (from 1.2 to 3.0 kW models)  and dual (from 3.3 to 6.0 kW models) Maximum Power Point Trackers (MPPT) to ensure the highest power output.

Easy Installation, Swift Operation

The use of Plug and Play connectors, both on the DC and AC side, as well as the wireless communication, enable a simple, fast and safe installation without any hassle.

By having a simple initial setup process, the unit will be up and running in a short time, making installation a breeze and outperforming competing products with a more complex commissioning routine.

The inverter management interface is one of the better features of the product, allowing users access to the advanced configuration settings, load manager, and dynamic feed-in control from any standard Wi-Fi enabled device, which could be a smartphone, PC or laptop, or a tablet.

Built-in advanced capabilities

The embedded logging system and direct transfer of the data to the internet (via Ethernet or WLAN) allows customers to benefit from remotely monitoring the power generation process using the Aurora Vision capability.

The state-of-the-art communication interfaces (WLAN, Ethernet, RS485) together with an efficient Modbus (RTU/TCP) communication protocol, Sunspec compliant, makes FIMER inverters usable throughout the world, able to interface with other companies’ monitoring and control modules. This means the ABB/FIMER inverters can be interfaced with most renewable energy generation arrays, battery storage and EV chargers, ensuring its potential for future resiliency when the user decides to upgrade their system.

These inverters are suitable for global operation, having software which is capable of interfacing with most national grids, as well as complying with the regulatory norms and procedures of utilities in most countries.

Energy Viewer

This new tool assists residential customers in remotely monitoring the performance of their own solar panels or microgrid and provides data analytics to optimise power plant performance and therefore improve energy resilience and self-sufficiency.

FIMER Inverters Major Strengths

  • Wi-Fi access to the user-friendly dashboard
  • Easy setup and commissioning
  • Future-proof design with embedded connectivity for smart building/smart grid integration
  • Dynamic feed-in control 
  • Remote firmware upgrade capability for inverter and components
  • Modbus TCP/RTU Sunspec compliant
  • Lifetime free-of-charge access to Aurora Vision remote monitoring system
  • FIMER PowerGain yield optimization

FIMER Inverter Warranty  

FIMER’s UNO-DM string inverters retail with a standard five-year warranty, which can be extended for another five years by purchasing additional coverage. This warranty cannot be extended to over 10 years, with it starting at the date of purchase. 

Warranty claims cannot be made if it has been modified or improperly installed, which makes choosing a qualified and reputable installer very important.

FIMER ABB Inverter Pros and Cons


  • Low-cost product
  • Industry standard inverter
  • Performs well in bright sunlight
  • Superior data output including earthing readings, performance reports, grid and panel voltages AC and DC


  • Overall energy output decreases if one or more panels damaged or shaded
  • Lacks ability to monitor each panel individually
  • Not the best option if solar panels are facing different directions



Q: Does the acquisition by FIMER mean that the ABB inverters were not good products?

A: No, the ABB design is highly reputed, and FIMER is carrying on with the innovative product line.

Q: How available are these inverters?

A: The former ABB Aurora inverters (now FIMER UNO-DM) are some of the most commonly found in existing solar systems, but not necessarily the most popular one for new installs. 


FIMER ABB Inverter Summary

FIMER’s UNO-DM string inverter is a budget-savvy option that comes in a variety of capacities to fit different systems. The excellent smart monitoring interface makes it easy to keep tabs on your energy output and usage. The five year warranty with the option to extend it to ten is in line with industry standards. If you are looking for a string inverter for your residential solar power plant, the UNO-DM is a pretty safe choice.

The inverter, based on a proven ABB design, is offered in several capacities, so it can meet the needs of a wide range of home solar installations. Users also benefit from Ethernet and Wi-Fi for connectivity, allowing them to easily monitor the inverter’s performance from a computer or mobile app. The neat plug-and-play connections, together with the easy commissioning process ensures that the installer can set up the inverter with the minimum of fuss, so it will be operational in the shortest time.

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Born in North West England, Jack kicked off his career in the insurance arena, dealing with claims for three years. Always up for a challenge, Jack leapt out of his comfort zone and embarked upon 5 years of excitement with the military.

Working for the Ministry of Defence, Jack specialised in counter-terrorism which took him to places such as Dubai, Oman, Iraq, Norway and Bahrain. During this period he worked with various Governments implementing strategic operations to prevent terrorism.

After travelling around various countries Jack increasingly came across various forms of solar from large solar farms to domestic solar panels. From here Jack took a keen interest in all things solar and started reading about the technological capabilities with a view to entering the industry after his career in the Ministry of Defence.

Once home after 5 fruitful years, Jack had 3 months leave in which he immersed himself in a solar crash course and got applying for jobs within the solar sector. He came across ESE Solar, a long-established forward-thinking company whose head office was only a stone’s throw away from him. He picked up the phone to see if there were any vacancies and within a week had a successful interview and obtained a full-time job, starting in the technical team.

Within the first few months, Jack onboarded in various online courses during work and social hours to speed up his knowledge of all things solar. Due to his strong work ethic and thirst for knowledge Jack was promoted to Head of Technical at ESE Solar. He currently leads the team and oversees the product development of new technologies within the company alongside assisting where necessary on their maintenance department.

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