SOLAR COLLECTORS FOR AIR HEATING : PROFITABILITY ANALYSIS

Solar energy constitutes one of the main alternatives for facing the energy problems of the future, taking into account the foreseeable depletion of the fossil fuels. Transpired solar air collectors are relatively simple alternatives, which do not need a continuous supervision and are mostly maintenance free. Their life cycle is relatively high, around 25 years, and the total investment can be fully recovered in the short-term. The aim of this master’s thesis is to analyze the feasibility of installing transpired solar air collectors as secondary systems in big industrial buildings, for heating purposes. The collectors would be designed for compensating the heat losses of a building which is mainly heated up by a heat pump system. Precisely, this work tries to evaluate the profitability of installing these collectors in Gävle, taking into account the particularities of this location in the considered study. This project work is focused on testing if these systems can provide enough thermal energy for heating up big-sized industrial buildings. For this purpose, firstly, the heat demand of the building for each month was calculated; secondly, the maximum output from the collector was estimated, using WINSUN simulator; and, finally, the energy difference that had to be covered by the main system was calculated. Once this was done, the yearly running cost for the main system and the total investment for the transpired air solar collector were estimated. Due to the lack of experimental data, the obtained results can only be taken as approximations. All the calculations and estimations have been made using WINSUN, a simulator that has been configured according to the particularities of the project. The results show that the solar collector provides a total thermal output of 29.700 kWh/year (system which has a total investment of 77.000 SEK). The total heat demand of the building is estimated to be of 87.100 kWh/year, being 51.800 kWh/year fulfilled by the heat pump system (which has a yearly running cost of 24.000 SEK/year). The collector has an average efficiency of 51,04%