Large scale pilot project with solar heating for a residential area – success and disaster

Magdalena Lundh, Department of Engineering Sciences, Sweden
Erica Löfström, Technology and Social Change, Sweden

Keywords

pilot plant, EU project, solar heating, user perspective, borehole storage, residential building, renewable energy

Abstract

This paper describes a socio-technical study of a heating pilot plant outside Stockholm, Sweden. The aim is to investigate discrepancies between technical and social evaluations.

The residential area comprises 50 units built in 2000-2001. The low temperature heating system consists of a large solar collector area and a borehole storage in rock with individual electrical backup systems. This is the first project combining solar collectors with borehole storage in rock. The solar energy is expected to cover 70 percent of the total heat demand for hot water and space heating. The project has faced several problems along the process; contaminated soil, faulty valves, exploding pipes and leakages. As a result, the need of electricity for heating has not decreased as much as expected by the inhabitants. Still, the residents are positive to the technology itself. It is being perceived as ‘natural’ and ‘clean’. The technical evaluation shows an obvious supply of heat from the solar heating system, while the residents are disappointed in the amount of ‘free’ energy. Technically, a borehole storage will be in full operation after three to five years due to substantial losses to the surroundings. However, this has not successfully been communicated to the residents. Furthermore, the guarantee period is unclear, due to the reparations, which causes worries about the future. The results of this study are to be useful in the future building of new kinds of energy systems.