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The building industry stands for a large part of the greenhouse gas emissions and energy use in the world and is therefore an important part to improve. Due to the need for improvements, solutions regarding energy efficiency have increased not only for single buildings but for neighborhoods and smaller districts. One example of this is Positive Energy Districts, which is a community level solution where buildings in the area can exchange energy and be more self-sufficient. This creates a local trade within the area and a reduced grid dependency, which can be beneficial financially, ecologically and socially. Creating microgrids within an area is helpful for the electrical grid because the grid needs stable frequency and renewable energy sources such as PV panels generate electricity irregularly which creates more strain. This study aims to investigate the trading of electricity from PV panels between buildings in the residential area of Rymdgatan, Borlänge.

Previous information existing in the area is regarding the Positive Energy Districts (PEDs), which means that an area produces more renewable energy annually than they consume while still being energy efficient and climate neutral. By creating blockchain-based microgrids in an area, energy can be shared between buildings through different types of market mechanisms. There is a lack of implementation regarding these solutions and this study aims to decrease the gap. In this thesis, simulation analysis is used to investigate energy use and electricity trading in the residential area Rymdgatan. The simulation takes place in the program IDA-ICE, where different scenarios of the model will be tested. The work is carried out in two stages: first, the energy performance of the buildings is simulated, then different models for local electricity trading between buildings are analyzed. These scenarios are first baseline, which does not exchange any electricity, then scenario 1 with the set price, scenario 2 with the time-controlled price and scenario 3 with the time-controlled price plus a community level battery implementation. These proposed scenarios will be evaluated on key performance indicators that are self-use rate, self-sufficiency rate, energy costs and carbon emissions.

Results show that the electricity produced by the solar panels in the area is only used to 23% with no trading and the rest is sent out to the conventional electricity grid. When adding trading in the area the self-use rate and self-sufficient rate increase and greenhouse emissions decrease. The most effective option in terms of local energy use and emissions reduction is the local trading combined with battery storage. Scenario 3 reflects a significantly improved performance, achieving a 97% self-use rate and 21% self-sufficiency. Electricity imports and costs decreased by 15% and 10% respectively, while carbon emissions were reduced by 15% compared to baseline. The findings highlight it is profitable to trade electricity in an area both financially, ecologically and socially, while it is more effective in combining market-based mechanisms with energy storage to enhance local energy use and reduce environmental impact. The results are also relevant for other areas with similar conditions, but there are opportunities for improvement for the study. Further research in the area could investigate auction-based trading or further development of the battery model.