Sofar Solar ESI 5kVA-S1-A: The smart solar inverter for everyone

Discover excellence in solar energy conversion with the Sofar ESI photovoltaic inverter. Designed by Sofar Solar, a leader in the solar industry, this inverter represents the pinnacle of modern solar technology.

• Maximum reliability: The Sofar ESI inverter is synonymous with reliability and durability. Built with high-quality components, it ensures flawless operation in the most demanding conditions.
  
  
• Exceptional efficiency: Enjoy optimal conversion of solar energy into electricity thanks to the superior efficiency of the Sofar ESI inverter. Every ray of sunlight is captured and transformed into usable electrical power to meet your energy needs.
  
  
• Advanced versatility: The Sofar ESI inverter offers remarkable versatility, adapting to a variety of applications and system configurations. Whether for a residential or commercial installation, it meets your needs with flexibility and efficiency.
  
  
• Advanced features: Equipped with advanced features such as dual MPPT inputs, the Sofar ESI inverter maximises the output of your solar system, allowing you to fully harness the potential of your photovoltaic installation.
  
  
• Quality guarantee: With Sofar Solar, quality is guaranteed. Enjoy complete peace of mind with an extended warranty on your Sofar ESI inverter, ensuring years of reliable, worry-free performance.

Choose solar excellence with the Sofar ESI photovoltaic inverter and transform your solar energy into a source of clean, renewable electricity for your home or business.

Sofar PowerAll

All-in-one residential energy storage system with integrated hybrid inverter
The SofarSolar high-voltage battery system consists of 1 to 6 BTS 5K battery modules and a single-phase ESI 3...6K-S1 hybrid inverter.
Up to six units can be connected in parallel, allowing for a configuration of up to 36 kW and 180 kWh.

Smart energy management

The battery modules are equipped with an integrated battery management system and a power control unit. The SOFAR PowerALL can intelligently adjust the battery’s output voltage and current based on its state of charge. This increases the available energy capacity.

Modular

The battery capacity can be easily expanded thanks to the system’s modular and stackable design. With plug-and-play cables, installation is both quick and user-friendly.

Safety

The LiFePO4 battery modules are equipped with CATL battery cells. In addition, there are multiple active and passive protection functions, provided by the BMS, the power control unit and the inverter. Fuses are installed on the battery side.

Who is this inverter for?

• Detached houses of 80 to 150 m² (ideal for a first solar installation)
• Flats with a single-phase meter
• Belgian homeowners wishing to feed electricity into the grid legally (Synergrid required)
• ‘Solar beginner’ profile: simple installation, no need to be an expert
• Optionto upgrade without changing the inverter: start without a battery, add up to 6 BTS modules later
  
  

Key benefit: Synergrid certification — explained simply

• What is Synergrid? It is the Belgian body that certifies equipment authorised to connect to the electricity grid. Without this certification, your installation cannot feed surplus electricity into the grid — and your network operator may refuse to commission it.
• The Sofar ESI 5K-S1-A is Synergrid-approved: you are fully compliant for Belgium
• Useful for the prosumer tax in Wallonia and Brussels: feeding into the grid is possible without penalty
• Essential for regional grant applications (some require approved equipment)

What this inverter actually does (3 functions)

• Converts: transforms the energy from your solar panels (direct current) into electricity you can use at home (230 V AC)
• Stores: redirects surplus energy to your Sofar BTS high-voltage battery for use in the evening and at night
• Switches over: in the event of a mains power cut, automatically supplies your home via the battery — without any noticeable interruption
• With 4 to 6 solar panels (4 kWp), it achieves 60 to 70% self-consumption in typical residential use
• Estimated savings: €600 to €1,000 per year on your electricity bill, depending on your consumption profile and local tariff

High-voltage battery: why it’s an advantage

This is the key technical difference compared to 48 V inverters such as the Deye:

• 400 V voltage instead of 48 V → higher conversion efficiency (fewer losses)
• Simplified wiring: lower currents, thinner cables, cheaper installation
• Full modularity: start with 1 BTS 5K module (5.12 kWh) and scale up to 6 modules in parallel = 30 kWh without changing the inverter
• Compatible only with Sofar BTS 5Kbatteries — integrated and optimised system (native BMS, no complex configuration)
• The modules are vertically stackable: saves space compared to multiple separate batteries

Advanced features

• 5 operating modes: self-consumption, off-peak hours, full sale, battery backup, off-grid mode
• AC Coupling possible: connect a second existing grid inverter to charge the Sofar battery
• Parallel function: two Sofar ESI units in parallel to double the power (guide available on the blog)
• Smart energy management via SolarMan Smart: real-time monitoring of generation, consumption and feed-in
• Remote updates (OTA): software updates without physical intervention

SolarMan Smart

SofarSolar is redefining the future of energy with smart inverters. Equipped with advanced monitoring features, our inverters come with a WiFi Stick as standard, paving the way for seamless connectivity. Choose your path to efficiency with options such as Ethernet, GPRS or LTE dongles. Transform every installation into a digital symphony, where solar power becomes a connected, smart and sustainable experience. SofarSolar, your partner for smarter and brighter energy.

Apple Store - Solarman Smart

Android - Google Play - Solarman Smart

Setup steps:

1. After launching the app, register as a new user or enter your current SOLARMAN login details.
2. Create a new system and enter the system data.
3. Scan the barcode on the logger stick to assign an inverter to the system.
4. Go to the newly created system to configure the logger stick (device/logger).
5. Press the button on the WiFi dongle for 1 second to activate the dongle’s WPS mode so that the smartphone can connect to the WiFi dongle.
6. Now select your local WiFi network for internet access and enter your WiFi password.
7. The WiFi dongle is now configured with the access details.