It is important to finely coordinate all existing components in the house to avoid unnecessary grid electricity consumption. Here, the system openness of my-PV is a significant advantage: a KOSTAL inverter, the associated smart meter, known as the KOSTAL Smart Energy Meter, in addition to a BYD battery storage and the AC•THOR from my-PV with its corresponding screw-in heating element.

To avoid the need for a separate meter for each manufacturer – which would entail additional costs – the AC•THOR from my-PV can access the surplus measurement of the KOSTAL Smart Energy Meter, thanks to system openness. This ensures that household appliances are primarily supplied with photovoltaic electricity, followed by charging the BYD battery, and only then – linearly and depending on the availability of PV power – the surplus is converted into heat. If more than 3 kW is available, the remaining small surplus is then fed back into the public grid with a minimal remuneration.

How did you come to choose my-PV?

The homeowner, Christoph R., became aware of the possibilities of photovoltaic heating due to the proximity to the my-PV company headquarters. "We also found a local electrical and heating company that installed the my-PV devices for us as end customers," explains homeowner Christoph R.

Were there any obstacles during the setup?

While the hot water boiler has its own screw-in socket for heating elements in the middle, since a significant surplus was expected from the 10 kWp PV system, the maintenance cover at the bottom of the storage tank was adapted. The heating engineer only needed to replace the existing flange plate with one with a suitable screw thread. According to my-PV, installing it at the very bottom provides more volume for heating.

Household members – hot water demand, etc.?

Two people are living in the single-family home during the week, with an additional person joining on weekends. With the 10 kWp photovoltaic system, there is sufficient surplus to meet the hot water needs for this number of occupants.

Is grid electricity used for hot water backup?

Only during the summer months, and even then, only in the afternoon, to allow the system to use PV surplus for hot water preparation during the day. Optional temperature backup is not used in winter. In winter, the pellet central heating system takes on this task alongside room heating. However, in summer, the pellet central heating system can be completely shut off, thus extending its lifespan.

What are the benefits, in your opinion, of the changes or expansion with photovoltaic heating?

"With the previously high feed-in tariffs now back to pre-crisis levels, we are only compensated with the market price for electricity fed back into the grid. This price is now roughly equivalent to the cost of pellets. For us, it's clear that retaining the self-generated energy in the house allows us to immediately save on pellets. Additionally, operating the pellet boiler at partial load in summer would be very inefficient, or the entire boiler would need to heat up just to warm a few liters of water. I prefer to use pellets when I truly need them, which is in winter," explains the homeowner, outlining his motivations.

Does the technology work?

Interested in real operational data? It's easily accessible through the my-PV Cloud. Real-time data demonstrates how well the various components work together.