Solar fraction used in water heating systems for south Brazilian climate changes scenarios
Acta Scientiarum: Technology
Solar thermal systems consist of water heating from the global solar radiation. Increasing atmospheric concentrations of greenhouse gases tend to increase the earth's surface temperature. The main objective of this work was to estimate the solar fraction obtained by means of solar heating systems for dwellings, for eight locations in the State of Paraná, in scenarios of possible climate changes projected until the end of the 21st century. F-Chart method was used to simulate the performance of
... he performance of solar heating systems based on the monthly average of solar radiation data, which determines the annual solar fraction or percentage of the energy demand that is covered by the solar installation. The results showed that with the impact of the climate changes, the decrease in the percentage of energy demand average that is covered by the solar installation was on average 14.3%, for both scenarios. The simulated values showed a slight decrease trend of radiation data and an increase of the solar fraction. All localities presented a characteristic seasonal behavior, with annual values of solar fraction between 82.4 and 129.8%, according to the studied localities. In relation to the monthly solar fraction, the values between November and March presented averages of solar fraction between 104 and 147.2%. But from May to August, the percentage of energy demand served by the solar installation does not reach the totality, with values between 53.6 and 99.9%. The results prove that the State of Parana has favorable climatic conditions for the installation of solar heating systems, even if it is installed for aggregation purposes, in order to reduce the electric power consumption.