Solar assisted district heating system with seasonal thermal energy storage in Eggenstein-Leopoldshafen

Abstract

The solar assisted district heating system with seasonal thermal energy storage in Eggenstein-Leopoldshafen (Germany) is the first system realized with existing renovated buildings. The system consists of 1600 m² flat plate collectors and a 4500 m³ gravel-water thermal energy store (TES) for seasonal thermal storage. Experiences gained within the BMU-project “Further development of the pit heat store technology” contributed to the design of the seasonal TES. This paper focuses on the design and construction of the gravelwater store. The monitoring concept of the solar assisted district heating system with focus on the gravel-water TES is presented. 1. Solar assisted district heating system The solar assisted district heating system with seasonal thermal energy storage in EggensteinLeopoldshafen (Germany) is the first system realized with existing renovated buildings. The project was initiated by a major refurbishment of the school, the gym and the existing district heating system. An additional gym with shed roof carrying 600 m² of flat plate collectors (FC) was built. Together with a public swimming pool and a fire station the district heating system consists of buildings with a gross building area of 12 000 m². For seasonal thermal storage of the solar heat produced by 1 600 m² of flat plate collectors a 4 500 m³ gravel-water thermal energy store (TES) is integrated into the district heating system, see Fig. 1.