Power system balancing in Swedish future scenarios of 2045 - Estimating contributions from V2G

Abstract: The ongoing climate change calls for an immediate decarbonization of society, where one important measure is a rapid transition of the energy system through an expansion of variable renewable energy sources, such as wind and solar photovoltaic power production. This transition imposes new challenges to the electrical power system, not least from a power balance perspective. This master’s thesis report consists of two parts, beginning with a tutorial on power system balancing. Starting from a theoretical approach, fundamentals of the power balance is presented, followed by a description of how this is realized in technology and on the markets for energy, balance and ancillary services. With the rapid transition of the energy system, it is of great interest to work with forward planning, and here this is done by using two electrification sce- narios for year 2045 developed by Svenska kraftnät, the Swedish transmission system operator, in their long term market analysis. The second part consists of two quantitative studies, both based on raw data from Svenska kraftnät scenario simulations. In the first study, an electrical grid simulation tool is developed, using the further developed network model Nordic 46, the grid simulation software PowerFactory and a Python script. This is validated by examples and comparisons with Svenska kraftnät simulations, and may be used for further studies. The second quantitative study focuses on power system balancing on a minute scale. This part is based on the work of a PhD project at the KTH Royal Institute of Technology, where production and consumption time series are interpolated based on their characteristics, and the need for balancing power is defined as the difference between consumption and production. A promising solution to abate this power imbalance is the use of bidirectional charging of electric vehicles, also known as vehicle to grid. A model of aggregated electric vehicles is built and used to investigate to what extent vehicle to grid can abate the power imbalance. Results indicate a great potential in the technology, but it relies on more intelligent battery control schemes as well as a market enabling it to be part of balancing the power system.