Sustainability Assessment of a Battery Storage System : Case study of a building-applied photovoltaic system

Sammanfattning: This bachelor thesis assesses the environmental sustainability of the implementation of a battery storage system in a commercial building. The thesis compares  two case studies, Case 1 being a commercial building with installed solar panels and Case 2 being a commercial building with installed solar panels and a battery storage system. Based on simulations the thesis investigates a battery storage system’s impact on sustainability in terms of CO2 emission equivalents and nuclear wastes. The study is applied in the geographical region of northern Stockholm. The models and calculations are conducted  in MATLAB, Excel and Google Sheets. The effects of the implementation depends on the electricity mix. Implementation of a battery storage system in a commercial building with solar panels, supplied with the Swedish electricity mix, increased the CO2 emissions with 3.6986 ⋅ 103 kg. A majority of the increased emissions was caused by the solar panels. They increased the CO2 emissions with 3.3876 ⋅ 103 kg in Case 1 and 3.6988 ⋅ 103 kg in Case 2. The nuclear waste was reduced with 878.3 g in Case 1 and 959 g in Case 2. The results also showed an increased consumption of renewable energy and a decreased load on the grid due to the implementation of a battery storage. For the sensitivity analysis the Swedish electricity mix was replaced by the European Union electricity mix. The resultant conclusion is that a commercial building decreased its CO2 emissions when solar panels were installed and a battery storage system implemented. The overall conclusion is that the environmental sustainability examination of the implementation resulted in an increasing emission of CO2 and a decreased amount of nuclear waste. Sustainable benefits such as an increased consumption of renewable energy of the building, a reduced dependence on the grid and improved conditions for phasing out nuclear power were also retrieved from the results. On a larger scale it has been made clear that battery storage systems are much needed in the conversion to renewable energy sources, and that research and investment in solar power and storage systems are of utter importance.