The Sofar Solar ESI-8K-T1: the three-phase hybrid inverter for large residential and commercial installations
The Sofar Solar ESI-8K-T1 is the 8,000 W three-phase hybrid inverter from the ESI range. It is designed for homes of 120 m² and above, as well as professionals and small businesses wishing to generate, store and manage their solar energy in three-phase. Its key features: 3 independent MPPT trackers supporting up to 16 kWp of panels, fully passive cooling (no fans) and IP66 protection — the highest level of protection against dust and water splashes.
What this inverter actually does
- It converts the energy from your solar panels into three-phase 380/400/415V AC electricity with a maximum efficiency of 98% and 3 independent MPPT trackers to optimise each string separately
- It stores surplus energy in Sofar BTS 5K lithium batteries (high-voltage LiFePO4, 350–435 V) for use in the evening, at night or in the event of a grid outage
- It secures your power supply with a switchover to backup power in under 10 ms — imperceptible to your electronic devices and household appliances
- It monitors your installation in real time via the SolarMan Smart app (iOS / Android), with built-in Wi-Fi at no extra cost
- It feeds surplus energy back into the grid if your contract allows
With 20 to 30 solar panels (8 to 16 kWp) and a Sofar BTS storage system of 10 to 20 kWh, a house of 120 to 200 m² or a small business can achieve 65 to 80% self-consumption, representing an estimated saving of between €1,000 and €2,000 per year depending on consumption patterns.
3 independent MPPTs: maximise the output of every section of your roof
Each of the 3 MPPTs operates completely independently. If your panels are spread across multiple orientations (south, east, west) or if some are partially shaded, the ESI-8K-T1 optimises the output of each string separately — without a underperforming section affecting the others.
The MPPT voltage range of 160 to 950 V offers great flexibility in string design, with a maximum PV input current of 25 A per MPPT.
Passive cooling: zero noise, zero maintenance
The ESI-8K-T1 relies exclusively on natural convection to dissipate heat — no mechanical fans. Three key benefits:
- Silent operation: no fan noise during operation, even at full load
- Increased reliability: the absence of moving mechanical parts eliminates the main source of failure in inverters
- IP66 protection: can be installed outdoors, in an unheated plant room, in a garage or in a garden shed
Scalable storage: from 5 to 30.72 kWh
The ESI-8K-T1 is exclusively compatible with Sofar BTS 5K lithium batteries (LiFePO4, 5.12 kWh per module, 400 V high voltage). Between 1 and 6 modules can be connected in parallel:
- 1 module (5.12 kWh): basic backup, small household
- 2–3 modules (10–15 kWh): full family home
- 4–6 modules (20–30 kWh): large house, small business or high consumption
⚠️ Important: the inverter operates without a battery in direct self-consumption mode. In the event of a grid outage without a battery connected, it shuts down (standard anti-islanding protection). Storage can be added after installation.
Monitoring: SolarMan Smart
Wi-Fi is built into the inverter — no additional dongle is required for basic monitoring. The SolarMan Smart app (iOS / Android) allows you to:
- View real-time production, consumption and battery status
- Check your daily, monthly and annual savings
- Diagnose faults remotely
- Manage multiple installations from a single account
Additional connectivity options: LAN (wired), RS485 / CAN (battery and meter communication), optional 4G for sites without Wi-Fi.
Installation
Installation must be carried out by a qualified electrician. Key points:
- Weight: 30 kg — two people are required for wall mounting
- Dimensions: 708 × 440 × 170 mm
- IP66 protection — suitable for outdoor installation or in unprotected indoor locations
- Passive cooling, silent operation
- PV start-up voltage: 200 V — power generation possible from the first hours of daylight
- Operates without a battery immediately upon installation
- RS485 and CAN compatible for communication with meters and batteries
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.
The future of energy in your home
The Sofar Solar ESI-8K-T1 is more than just an inverter: it is the heart of your energy self-sufficiency. With its 8 kW output, scalable storage and responsiveness, it ensures your home is always powered, more economical and more environmentally friendly.
FAQ – Sofar Solar Tri 8 kW Hybrid Inverter – ESI-8K-T1
1. What is the Sofar Solar ESI-8K-T1 hybrid inverter and what is it designed for?+
The Sofar Solar ESI-8K-T1 is an 8 kVA / 8,000 W three-phase hybrid inverter. It combines three functions in a single unit: converting the solar energy generated by your panels (DC → AC 380/400/415 V three-phase), managing storage in lithium batteries, and providing automatic backup power in the event of a grid outage. With a maximum efficiency of 98% and a European efficiency rating of 97%, it is an ideal solution for family homes, small businesses or farms wishing to maximise their self-consumption and energy independence.
2. What is the maximum solar panel capacity that can be connected to the Sofar ESI-8K-T1?+
The ESI-8K-T1 accepts up to 16,000 Wp (16 kWp) of solar panels at the input, representing a 200% PV oversizing compared to its rated power. It features 3 independent MPPT trackers (1 string per MPPT), each supporting an input current of 25 A, with an MPPT voltage range of 160 to 950 V and a maximum input voltage of 1,000 V. This three-phase, 3-MPPT architecture is particularly well-suited to installations with multiple roof sections facing different directions, or where partial shading is present.
3. Which batteries are compatible with the Sofar Solar ESI-8K-T1 and what storage capacity is possible?+
The ESI-8K-T1 is specifically designed to work with Sofar Solar BTS 5K LiFePO4 lithium batteries (5.12 kWh / 100 Ah / 400 V high voltage). It supports a battery voltage range of 350 to 435 V, with a maximum discharge current of 24 A. The storage capacity is fully scalable: from 1 to 6 BTS 5K modules in parallel, i.e. from 5.12 kWh to 30.72 kWh. This allows you to tailor the runtime to your consumption profile and upgrade the system over time, without replacing the inverter.
4. Does the ESI-8K-T1 work without batteries? Can batteries be added later?+
Yes, the inverter can operate without a battery in direct self-consumption mode: the solar energy produced is consumed immediately by your appliances, and any surplus is fed back into the grid (or lost if feed-in is not configured). Storage can be added at any time thanks to the modularity of the BTS 5K system, allowing you to start with a controlled budget and gradually increase autonomy. Please note that without a battery, the emergency power supply (EPS) function is not available during a grid outage.
5. What happens during a power cut? Does the ESI-8K-T1 provide a backup power supply?+
Yes. The ESI-8K-T1 features an automatic switchover to off-grid mode (EPS) in under 10 ms during a mains power cut — a delay that is virtually imperceptible to the vast majority of electronic devices (computers, internet routers, fridges, lighting, etc.). This function requires one or more Sofar BTS 5K batteries to be connected and sufficiently charged. The power available in emergency mode corresponds to the rated power of 8,000 VA, which is sufficient to power an entire home or business premises.
6. How can I monitor and control the installation remotely using the Sofar ESI-8K-T1?+
The inverter comes as standard with Wi-Fi, LAN (Ethernet), RS485 and CAN. A 4G module is available as an option for sites without a fixed internet connection. Monitoring is carried out via the SolarMan Smart app (available on iOS and Android), which allows you to track solar production, battery status and consumption in real time, schedule charging windows, receive alerts and update the firmware remotely. The integrated EMS (Energy Management System) automatically optimises energy flows between the panels, battery, grid and domestic consumption.
7. What operating modes are available on the Sofar ESI-8K-T1?+
The ESI-8K-T1 offers several operating modes that can be configured via the SolarMan app: self-consumption (priority given to local consumption), battery priority (maximum storage before feeding into the grid), off-peak hours (battery charging at reduced grid rates), grid feed-in (reselling surplus energy), and off-grid mode. These modes allow you to adapt your energy strategy according to consumption habits, current tariffs (off-peak/peak hours, prosumer tax, etc.) and weather conditions.
8. What are the dimensions, weight and installation requirements of the Sofar ESI-8K-T1?+
The inverter measures 708 × 440 × 170 mm and weighs 30 kg. Its natural convection cooling (fanless) ensures silent operation and extended lifespan without the need for mechanical maintenance. IP66 protection — a higher rating than IP65 — offers complete resistance to dust and powerful water jets, allowing for installation both indoors and outdoors (garage, utility room, sheltered façade). The operating temperature range is -30 °C to +60 °C (derating above +45 °C), with a PV start-up voltage from 200 V for early start-up as soon as the sun rises.