The growing share of weather-dependent power generation in the Swedish power system is challenging the stability of the whole system. Therefore, the need to increase system flexibility by frequency regulation reserves is enlarged. Nowadays, the reserves are mainly supplied by Hydropower. The TSO, Svenska kraftnät, is opening the market to attract new participants to provide the balancing capacity to increase the competition between resources and change the market dynamics. This thesis explores the potential of four different technologies in the future FCR-D up- regulation market: Hydropower, Wind power, battery energy storage systems (BESS) and demand response (DR). A FCR-D upregulation market-clearing model has been built with logical cost calculation and volume estimation of each actor in the FCR-D market. Sensitivity analysis and the market-clearing model have been conducted through Python software. Based on the scenario selection method, this research provides an overview of the future FCR-D up- regulation market with the participation of new actors. The results show that the availability for FCR-D up market of some Hydropower actors has decreased over the years. The Wind power has the highest cost among the studied technologies and the costs of the BESS and DR are competitive. Besides, in high spot price years, the bids from BESS and DR have higher chance to be accepted which creates opportunities to attract new actors to join the market. The new actors' introduction could lower the average FCR-D clearing prices from 19.3 - 70.7 % from 2016 - 2020. Finally, from the volume change scenario, the BESS and DR actors are found to be the price-makers that could influence the FCR-D price with rising available volume.
