Potential for Solar Energy on Rooftops in the Municipality of Uppsala

Abstract: Uppsala City Council has set up milestones for each decade from year 2020 to 2050 to steadily reduce the greenhouse gas emissions per capita in the municipality of Uppsala. The Climate Protocol is working on a roadmap with guidelines on how to achieve the current climate goals. The roadmap is expected to be finished in year 2014, and it is currently being investigated to what extent solar energy could contribute to achieving the climate goals. The purpose of this study is to estimate the solar energy potential in the municipality of Uppsala for the years 2020 and 2050 based on an assessment of what a prospective utilization of solar energy systems on rooftops could potentially generate. The addressed solar techniques are photovoltaics based systems and solar thermal collectors. The results indicate that an optimal rooftop area of 5.9 km² is estimated in Uppsala municipality by 2020, and 8.8 km² by 2050. The total solar energy potential in the municipality is estimated to 1.5 TWh in 2020 and 1.9 TWh in 2050. Thus, approximately half of all the buildings energy consumption in the municipality could potentially be covered by solar energy. A sensitivity analysis is carried out to test the results by altering input parameters and components. The sensitivity analysis indicates that the solar energy potential would increase by optimizing roof deployment areas when constructing new buildings and improving the solar efficiency for photovoltaics. The results indicate that solar energy could cover 49 percent of the municipality’s expected energy demand in 2020 and 64 percent in 2050.