A short explanation of the system

The AC•THOR 9s is installed with a my-PV WiFi Meter to detect surplus energy from the PV system. Thanks to my-PV’s system openness, surplus measurement can also be achieved using devices from my-PV’s many compatible partners or standard smart meters. All my-PV devices are compatible with the P1 port of digital meters, ensuring seamless integration.

The system includes a 200-liter heat storage, equipped with three 2,000 W heating elements. The hot water storage is connected to a buffer storage for the heat pump. The PV system powering this setup includes 36 PV panels and 18 microinverters which sum up to a total power of 14.4 kWp.

Using surplus solar energy, the AC•THOR 9s efficiently heats the boiler to a maximum temperature of 95°C, optimizing the utilization of sustainable energy produced by the PV system. When water temperatures drop below 45°C, the AC•THOR 9s activates up to two of the heating elements, supplying 4,000 W of power to raise the temperature to approximately 49–50°C. On sunny days with sufficient solar irradiation, all three heating elements, delivering a combined 6,000 W, are employed to achieve the target temperature of 95°C.

In July 2024, the household transitioned fully from gas supply to renewable energy. During the ongoing renovations, the heat pump is currently dedicated to heating the home. Once renovations are completed, the heat pump will also preheat water in the boiler to a temperature range of 50 to 55°C. With sufficient solar energy, the AC•THOR 9s will further enhance this process by heating the boiler to 95°C using surplus PV energy.

Were there any obstacles or special features during the setup?

The owner, who works as an electrical engineer, found the installation of the photovoltaic power manager AC•THOR 9s to be, as he puts it, "a piece of cake."  This involved several steps, such as adjusting the distribution box, installing circuit breakers for the my-PV WiFi Meter and a dedicated circuit for the boiler and laying the necessary cables. Commissioning was also straightforward thanks to the manual. It was especially helpful that all the required documents were available in Dutch language.

However, the experienced engineer advises homeowners without technical expertise to rely on professional electrical service providers to ensure a proper and safe setup.

How many people in the household are covered by the hot water supply?

According to the homeowner, three people live in the former farmhouse and shower multiple times a day. He estimates their annual hot water consumption to be around 150m³.

What savings are expected?

The customer expects savings of 40 to 45%, which would be double the amount of savings compared to the time before PV-energy was stored in the form of heat. The first key area of savings comes from the reduction in grid fees due to the increased PV self-consumption.

Prior to the installation of AC•THOR 9s, over 5600 kWh of surplus PV energy was fed back into the public power grid annually. Since the installation of the device, this amount has been significantly reduced. For instance, during October and November 2024, only 41 kWh of surplus energy were fed into the grid, compared to 180 kWh during the same period in 2023. In sunnier months, even greater use of self-produced electricity for heat is achievable.

The second area of savings comes from the ability to heat the boiler from 45°C to 95°C using self-generated green energy from the PV system, making it the most cost-efficient energy source, as the homeowner is not dependent on external price fluctuations any longer.