Annual Evaluation of the Solar-Electric Company Building 2025

The 2025 annual evaluation once again demonstrates the high efficiency of the solar-electric energy concept implemented in the my-PV company building. At the same time, it highlights the significant impact that company growth and increasing electromobility have on energy demand. In particular, electricity consumption for electric vehicles has risen considerably, as both the company fleet and the number of employees with private electric vehicles continue to grow, all of whom can charge free of charge using solar power.

Since the first solar-electric company building was commissioned in 2021, my-PV has published a detailed annual analysis of energy usage, energy sources and photovoltaic surplus - an overview can be found on the page for the solar-electric company building. The 2024 annual evaluation still reported calculated energy autonomy of 119%; the picture for 2025 is markedly different.

Energy consumption in detail

The building's total energy demand across all sectors amounted to 95,251 kWh in 2025. This was broken down into 46,688 kWh of operational electricity (including cooling and ventilation), 17,332 kWh for space heating, 1,606 kWh for hot water and 29,625 kWh for electromobility.

In addition, extensive long-term tests were carried out over the past year, increasing electricity demand by around 50% compared with 2024. Electromobility also continued to grow: as my-PV provides employees with free charging in its parking areas and the company fleet has expanded, consumption in this sector rose from 26,000 kWh (2024) to 29,625 kWh.

On the supply side, consumption was met by 43,282 kWh of directly used PV electricity (PV self-consumption) and 51,969 kWh drawn from the grid. 'Directly used' here means without a permanently installed battery storage system in the company building. In total, the building's own PV system generated around 85,031 kWh, of which 41,749 kWh was fed into the grid as surplus electricity. Although the PV system is rated at 100 kWp, the lower annual yield is due to 30 kWp of the system being facade-integrated. These modules generate less energy in summer, but provide the solar energy needed precisely in winter - the heating season - thanks to the sun's low angle of incidence.

Calculated energy autonomy below 100% for the first time

The sharp increase in consumption meant that calculated energy autonomy fell below 100% for the first time in 2025. This means that total energy consumption exceeded the amount of energy generated by the building's own PV system for the first time.

Remarkably, self-consumption still increased - to 50.9%. For the first time, more than half of the solar electricity generated on site was used directly in the building, without delayed use via battery storage. Charging of electric vehicles is not scheduled according to the availability of solar power either; given the size of the fleet and the charging window being limited to office hours, this is not feasible over the course of the year.
Especially in times of low feed-in tariffs or potential feed-in restrictions, this demonstrates how essential high self-consumption is.

my-PV products offer a simple and cost-effective way to increase self-consumption by capturing and precisely controlling excess energy down to the second - both for hot water production and for solar-electric heating via core activation with heating wires. The continuously adjustable power regulation enables efficient, low-loss use of PV surplus.

Key figures for 2025 at a glance

Conclusion: future-ready building technology in action

Despite the increase in total consumption, the current figures once again confirm the high performance of the building concept. With self-consumption of 50.9% and calculated energy autonomy of 80.3%, the company building remains an excellent example of efficient solar-electric building technology in commercial applications.

Another advantage: heat generation is completely maintenance-free, silent and without moving parts. The motto "Cables Instead of Pipes" not only simplifies installation but also reduces operational complexity.

From today's perspective, my-PV would implement the building again in exactly the same way at any time. Solar-electric building technology has once again proven to be the ideal solution for low-energy buildings - cost-effective, efficient and environmentally friendly!