Sammendrag
During an increased relevance of climate change mitigation, the role of decentralized energy supply systems is steadily increasing. Real estate owners often aim to decrease the operational energy costs of their properties. This can not only be achieved by energy refurbishments, but also by increasing energy supply efficiencies and self-sufficiencies of the properties. Besides decreasing their costs, they also contribute to primary energy savings.
In this project report we aim to minimize the overall energy supply costs of a residential building complex with a local heat network and connected to the electricity and district heating grid. The complex includes photovoltaic modules, a combined heat and power plant, a thermal storage and a battery. We create an optimization model optimizing the operations of the applications in terms of energy supply costs. The model is solved for three different seasonal time periods of the year, to evaluate the difference in the operational behavior of the applications and the impact of different air temperatures on energy costs. In this report, we solve the model for the case of residential buildings with several rental flats each, located in Bavaria, Germany, owned by one investor.
The results of this case give insights in the seasonal variation of the operations of the mentioned technologies and how they are impacted by external prices for electricity, natural gas and district heat. The optimization shows, that the main driver for energy costs are gird purchases for electricity and heat. It can also be seen, that the deployment of storage units is a major contributor to cost savings, since they are charged in times of low market prices and discharged during peak market prices. For the analyzed case, prices for energy from grid have the most impact on the operations in the summer period. Since heat and electricity demand in autumn and winter cannot possibly be met by the existing energy supply infrastructure. Nonetheless, a set up with a combined heat and power plant, renewable energy sources and storages entail cost savings for the overall energy supply.