At the Eurosun 2008 in Lisbon, the thematic of large scale thermal storage was part of the topic range. Per Alex Sørensen from Planenergi, Denmark did provide me a copy of three papers that I refer here. Unfortunately, it seems that one cannot get the proceeding online. (This ought to be changed for any renewable energy and environmental conference, where proceedings ought to be open access and free for reading).

T. Schmidt and D. Mangold from the Steinbeis Research Institute, Stuttgart, Germany mailto:schmidt@solites.de did present a paper including three thermal storage projects, a 5,700 m3 water tank i Munich, a borehole storage 37,500 m3 volume in Crailsheim and a 4,500 m3 pit storage in Eggenstein.

F.Ochs, J. Nussbeicker-Lux at.al. presented the following abstract to their paper “Solar assisted district heating system with seasonal thermal energy storage in Eggenstein-Leopoldshafen” with the following 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 gravel-water store. The monitoring concept of the solar assisted district heating system with focus
on the gravel-water TES is presented.

Per Alex Sørensen, mailto:pas@planenergi.dk, from PlanEnergi, Leo Holm and Niels Aage Jensen from Marstal Fjernvarme, Denmark presented a paper “Water Storages, Solar thermal and Heat pumps in District Heatin” with the following abstract:

In 1996 Marstal Fjernvarme (Marstal District Heating) established 8.000 m2 solar collectors that covered 13% of the yearly consumption. The solar fraction in later built district heating plants goes up to 25% covering the total summer load, but several district heating companies especially natural gas fired combined heat and power plants want a higher solar fraction in order to replace expensive natural gas. Therefore new projects with solar fractions of 50% are designed and are expected to be implemented  in 2009. Design calculations show that the production price for heat from solar thermal plants with 50% solar fraction can compete with heat prices from natural gas fired CHP plants.