Variation of System Performance with Design and Climate for Combisystems in Sweden

In Sweden, 90% of the solar heating systems are solar domestic hot water and heating systems (SDHW&H), so called combisystems. These generally supply most of the domestic hot water needs during the summer and have enough capacity to supply some energy to the heating system during spring and autumn. This paper describes a standard Swedish combisystem and how the output from it varies with heating load, climate within Sweden, and how it can be increased with improved system design. A base case is defined using the standard combi- system, a modern Swedish single family house and the climate of Stockholm. Using the simulation program Trnsys, parametric studies have been performed on the base case and improved system designs. The solar fraction could be increased from 17.1% for the base case to 22.6% for the best system design, given the same system size, collector type and load. A short analysis of the costs of changed system design is given, showing that payback times for additional investment are from 5-8 years. Measurements on system components in the laboratory have been used to verify the simulation models used. More work is being carried out in order to find even better system designs, and further improvements in system performance are expected.

Perceptions of climate change at ski resorts in midsouth of Sweden

Climate change as a phenomenon will imply new risks for the ski industry. Intergovernmental Panal on Climate Change presents three future scenarios, during the periods between 1990-2100, in forms of increased temperatures, a rise in the sea level and seasonal variations, variables out of which two have direct impacts on the ski industry. The aim for this study was to explore and compare attitudes towards climate change between five ski resorts located in mid-south of Sweden. This was done through in depth interviews in both face to face and by telephone. The result of the study was that all the chosen ski resorts were aware of climate change as a phenomenon but have not yet recognized its consequences. All ski resorts use methods to maintain skiing i.e. artificial snow production though not because of climate change.