Results of the Groningen CSHPSS (Central Solar Heating Plant with Seasonal Storage) project

In Groningen, the Netherlands, a Central Solar Heating Plant with Seasonal Storage (CSHPSS) in the soil has been realized and has been in operation since the autumn of 1984. The system has been monitored for five years. During this period the system functioned without major problems. The measured solar contribution of the system is about LSVo lower than the design value. Main reasons for this lower output are a lower collector output and higher storage heat losses than expected. This paper summarizes the monitoring results.