Trosvik School

In collaboration with SINTEF, ECO STOR and Fredrikstad Municipality, Trosvik School is part of an innovative pilot focused on the reuse of electric vehicle (EV) batteries. The school’s solar panel system is connected to a battery storage solution based on second-life EV batteries. The aim is to store surplus solar energy and maximize the use of self-generated electricity during periods of high demand and elevated electricity prices. 

System performance and key insights 

The battery storage system was officially commissioned in January 2025. Since then, it has been actively collecting operational data, providing valuable insights into how used EV batteries can support local energy management strategies. 

During the winter months, the system achieved a peak shaving effect of approximately 10 kW, although analyses indicate a higher potential. The school’s relatively stable load profile, combined with suboptimal control system settings, has so far limited performance. Based on early operational data, improvements to the control system are now being planned. These enhancements are expected to increase peak shaving potential to up to 30 kW during the upcoming winter. 

Due to the modest size of the solar PV installation (maximum output of 36 kW), solar generation has only contributed to battery charging during summer. A technical downtime in July 2025, a period of high solar production and savings potential, limited overall system benefits. However, the financial impact was minimal, as electricity prices are generally low during the summer holiday season. Since then, the system has been upgraded to restore full functionality and minimize future downtime risks. 

Through the pilot project, Trosvik School serves as a leading example of sustainable energy solutions for public buildings and contributes valuable insights in the field of circular energy systems. 

The battery systems will operate and collect research data until 2026. Their performance will be continuously optimized based on collected data and experience. After the project period, the systems will remain operational to maximize resource use and can be easily relocated if needed. 

The battery systems will operate and collect research data until 2026. Their performance will be continuously optimized based on collected data and experience. After the project period, the systems will remain operational to maximize resource use and can be easily relocated if needed.

Discover our other demonstration sites, Lempäälä House and Rudskogen Motorsports Center.