Sustainable living
Belgian family home relies on the AC•THOR
Belgian family boosts PV self-consumption to 74% with AC•THOR, all without battery storage.
Facts about the project
- Owner/Planner/Installer
- Location
- Photovoltaic output and orientation
- Building type
- Year of construction and size
- Heat storage size
- Inverter and battery storage
- my-PV product
- System control
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In the Belgian town of Linkebeek, not far from Brussels, a family of five has transformed their 1960s home into a modern, solar-powered household – with a clear goal: to reduce reliance on fossil fuels such as gas and wood by maximizing self-consumption of PV energy.
At the heart of this modernization is the AC•THOR, the continuously regulated solar power diverter that converts generated solar power into heat.
Following extensive renovation work, the house now accommodates two adults and three children – over a comfortable 170 m². With an estimated daily hot water demand of around 275 liters, finding an intelligent solution for reliable hot water supply was a priority.
What was the way to my-PV?
The homeowner Thomas D. learned about my-PV through Thermo-Bati, a company specializing in HVAC installations. After attending one of my-PV’s popular webinars, he was convinced that the concept of PV heat aligns with the sustainability & economical goals for his new home. According to Thomas D., installing the AC•THOR went absolutely smoothly. The only challenge was configuring the HUAWEI Smart Dongle – particularly during installation, connection, and setup.
Personal customer opinion and resumee
The homeowner reports high satisfaction with both the installation process and system performance. The ability to monitor the setup remotely and customize the energy flow visualization adds transparency and ease of use: “I am completely positive about the benefit of using AC•THOR in my configuration. This project proved to be easy to install, operate and monitor from distance with the my-PV Cloud. I particularly like the ability to add additional information via the widgets to make the various energy flows of my system more visible.”
Short explanation of the system
The photovoltaic system has a capacity of 4.4 kWp and consists of ten modules mounted on a south-east facing roof. It is connected to a HUAWEI SUN2000-4KTL-L1 inverter, with surplus information transmitted to the AC•THOR via the HUAWEI Smart Dongle. An Enovates ENO One wallbox for EV charging is also integrated. The household deliberately operates without battery storage.
The heating system combines two storage units:
300 L buffer tank (Joule)
Primarily used for space heating, but also able to provide domestic hot water. It is supplied by three different energy sources:
PV surplus via the AC•THOR
A water-bearing wood stove (Haas & Sohn)
A gas boiler
270 L thermodynamic boiler (Atlantic Explorer V3)
Dedicated exclusively to domestic hot water (DHW) and completely disconnected from the gas grid. It is linked directly to the AC•THOR via a dry contact pair of cables.
The thermodynamic boiler is manually set to a base target temperature of 50 °C to ensure a minimum volume of hot water is always available, independent of PV production. When PV surplus is detected by the AC•THOR, the boiler automatically switches to boost mode (a non-adjustable factory setting of Atlantic thermodynamic boilers). In this mode, the target temperature rises to 62 °C. This strategy provides two key advantages:
Maximises self-consumption of PV-generated electricity
Increases hot water availability on sunny days, compensating for reduced PV output on cloudy days
Special network requirement
The house is connected to a three-phase IT network without a neutral conductor, a grid type common in some regions of Belgium. For this reason, a single-phase AC•THOR was chosen instead of the three-phase AC•THOR 9s, which requires a neutral line. The device was configured in Mode 4 (M4).
Mode 4 was originally designed for heat pumps. It allows the user to define a s urplus power threshold and a minimum duration for which this threshold must be exceeded. Once met, the heat pump starts and runs as long as surplus power is available and the target temperature has not yet been reached. At the same time, the AC•THOR can direct additional surplus power to the heating element.
In this setup, the device first powers the 3 kW heating element in the buffer tank, then the thermodynamic boiler. This process is controlled via a smart grid function that only activates if at least 700 W of PV surplus is continuously available for a minimum of 15 minutes.
Although not a standard installation, this custom configuration operates reliably and demonstrates the flexibility of my-PV products, even under technically demanding grid conditions.
People in the household and hot water demand
The home is occupied by a family of five – two adults and three children, of which two are teenagers. Daily hot water demand is estimated at approximately 275 liters, making the most efficient use of PV power available crucial to ensure a continuous hot water supply.
Is hot water backup used
Although AC•THOR’s hot water backup function is not currently in use, the system relies on natural fallback options: a wood stove provides heat during the evening, and at night – when no more wood is added – the gas boiler may activate, if needed.
Cost optimization and first results
Although the AC•THOR was only installed in mid-2025, early results already show a clear improvement in energy efficiency:
Self-consumption increased from 57% (July 2024) to 74% (July 2025).
Autarky rose in the same period from 31% to 54% – and all without battery storage!
Exported surplus power dropped significantly, from 401 kWh to 271 kWh, which shows the significant increase in PV self-consumption.
The homeowner anticipates further reductions in gas and wood consumption, particularly during the transitional months of spring and autumn. In addition, he plans to optimize the system even further by activating the my-PV DTO feature in the my-PV Cloud. This function enables hot water heating based on the lowest spot market electricity prices – provided a dynamic electricity tariff is available. He continues to stay informed on the topic through our webinars.
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AC•THOR
in use
Simple & efficient: AC•THOR controls electrical heat sources depending on the availability of PV energy and heat demand. And that for both hot water, as well as for space heating.
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