June 17, 2026|General

Protect your heat pump and increase self-consumption with real PV heat.

The combination of a modulating heat pump and solar-electric direct heating with the AC•THOR reduces heat pump cycling by up to 55% - potentially extending its service life by up to eight years while significantly increasing photovoltaic self-consumption.

Heat pumps are a significant investment - depending on the system capacity and the building, costs for a detached or terraced house typically range between € 15,000 and € 25,000. To ensure this investment pays off, the heat pump must operate reliably for as long as possible. A key factor is not only its running time but, above all, its cycling frequency. Every start and stop places stress on the compressor - the most sensitive and expensive component of the system. Recent simulations demonstrate how solar-electric building technology from my-PV can significantly reduce this stress.

Up to 55% fewer starts per year

Simulations carried out using a widely used industry tool clearly demonstrate the potential. The example examined a low-energy house in the Bamberg region with 150 m² of heated floor area, a 10.2 kWp PV system, and a 10.2 kWh battery storage system:

Heat pump only: 2,377 operating hours and 606 starts per year
Heat pump + AC•THOR (+ immersion heater or electric boiler): only 1,791 operating hours and 273 starts per year

This corresponds to a 55% reduction in start-up cycles. Even in existing buildings with higher heating demand, the effect remains clearly measurable: the number of starts decreases from 759 to 405 per year - a reduction of 47%.

The background is simple: during the months from May to September, photovoltaic heat via the AC•THOR takes over the entire domestic hot water supply. The heat pump is blocked during this period and does not need to switch on and off for every small hot water demand - exactly the kind of cycling that causes the most wear and tear.

The benefit? By eliminating the heat pump’s entire operating time during the sunny months (approximately March to October, depending on the region), the system reduces strain on the heat pump - without any loss of comfort in the household. If a week of rainy weather occurs during the sunnier months, a domestic hot water backup function can ensure comfort depending on storage size and hot water demand. In such cases, just a few kWh are enough to raise the temperature to a minimum level if the sun stays away for longer periods.

Eight years longer service life = up to € 4,800 in savings

The compressor of a heat pump is designed for around 60,000 operating hours. Anyone who protects it benefits directly in financial terms. In the simulated new-build scenario, the combination with the AC•THOR increases the calculated service life from 25 to 33 years - an increase of eight years.

Based on an investment of € 15,000, this translates to:

Without my-PV solution: € 600 per year (25 years of service life)
With my-PV solution: € 455 per year (33 years of service life)

Over the entire lifetime, this adds up to savings of around € 4,800 - not including additional electricity or maintenance costs.

Even in existing buildings, the calculation remains clearly positive: the service life increases from 26 to over 31 years, with savings of around € 2,900. The additional investment for solar-electric heat generation with AC•THOR and an immersion heater or electric boiler is - depending on the configuration - modest, at around € 1,000 to € 1,300.

Every kilowatt-hour from the roof goes into heat

The second major lever is increasing self-consumption. A heat pump requires a certain minimum PV output to start - smaller surpluses remain unused or are fed into the grid. In addition, during fluctuations in household demand or solar irradiation, the heat pump may draw unnecessary grid electricity due to its inertia. The AC•THOR, on the other hand, operates with stepless control: every excess kilowatt-hour is immediately converted into heat, even under variable production caused by passing clouds. This effectively closes the gap between photovoltaic generation and heat production, noticeably increasing self-consumption and reducing dependence on feed-in tariffs.

Double benefit for homeowners

With solar-electric building technology from my-PV as a complement to the heat pump, homeowners benefit twice: the modulating heat pump remains in optimal condition for longer and needs to be replaced significantly later, while at the same time the self-generated solar power is used more efficiently. The modest additional investment is easily offset by the resulting savings. This makes the rooftop PV system even more economical and helps homeowners become more independent from external factors such as feed-in tariffs or rising electricity prices.

How easy is it to implement?

Various my-PV customers rely on relieving the heat pump:

Detached house in Upper Austria: After several heat pump failures, a backup system was required - this was achieved using solar-electric building technology.
Detached house in Thuringia: To support both the oil heating system and the heat pump, the homeowner relies on autonomous heat generation from my-PV.

Solar-electric building technology protects the primary heating system

The formula is simple - and convincing: half the operating time = double the service life.
With solar-electric building technology from my-PV, this rule of thumb becomes practical reality. This keeps the heat pump or heating system in optimal condition for longer, while at the same time increasing self-consumption and the overall economic efficiency of the PV system.