Effektivisering av kylsystem på Utö värdshus

Sammanfattning: Energy consumption is at present a major political issue, and numerous projects that comprise many nations are currently in process to increase energy efficiency and bring down energy dependency. As a member state of the EU, Sweden now faces the challenge of implementing substantial energy-saving measures until the year 2016. One of these measures is the project “Green Islands” financed by the EU that intend on creating sustainable islands in areas around the Baltic Sea. The Archipelago Foundation leads the project that concerns the Stockholm archipelago, where focus has been placed upon decreasing energy usage in businesses and services on Utö among other islands. The inn at Utö is included in the project; where replacing or improving the cooling system for the cold storages is desired in order to reduce the use of energy.This report examines the possibility of changing or improving the current cooling system along with the potential savings that would result from an improvement of energy efficiency. The project was conducted through a modeling study in which significant aspects such as cooling demand, the availability of energy sources, and local conditions have been considered. The conclusion gives an account on savings of carbon dioxide emissions, energy, and capital. The capital savings will act as a foundation on which the size of investment will be proposed with the aid of economic calculations.The results show that an implementation of absorption cooling is not a valid method for increasing energy efficiency in this case. The local conditions are not sufficient for generating cooling with heat energy. It was found that the optimal technique for increasing energy efficiency was to decrease the condensing temperature for the existing compressor systems. Two eligible ways of doing this were studied. Implementing variable condensation would reduce electrical usage by ca. 15300 kWh per year, which produces ca. 15600 kr of yearly savings. Furthermore, carbon dioxide emissions would decrease by 141 kg per year. Implementing a water cooled condensing system would also result in beneficial savings. For this method, it was found that electrical usage would reduce by ca. 13800 kWh per year, with a resulting ca. 14100 kr of yearly savings. In this case, the carbon dioxide emissions would decrease by 127 kg per year. Beyond these measures, simpler actions can be done, such as improving upon the isolation of the door strips that, in both cases, are recommended.There is thus a potential to reduce the electricity consumption that generates economic and environmental savings that does not require any major efforts. Along with a considerable relative reduction of electric energy use follows savings in carbon dioxide emissions and operating costs, but since the capital savings is fairly low, large investments are not possible. Until the absorption cooling technology matures and becomes cheaper and more appropriate for the inn’s cooling requirements, it will have to step aside for the well tested compressor technology.