The high emission intensity of coal-fired power plants (CFPP) leads to the inevitable next step towards energy transition, the coal phase-out. One challenge is the subsequent use of still-functioning assets. Re-purposing these assets avoids value loss and creates new opportunities for coal regions. Therefore, this study considers the sector coupling technologies Power-to-Gas (PtG) and Gas-to-Power (GtP) as re-purposing options. First, a multi-variable Mixed-Integer Linear Programming optimisation model is established. This model includes the participation of the plant in the current (2020) and future (2030, 2040) electricity and natural gas spot-markets and the balancing power market while fulfilling existing contracts, and allows for determining the re-purposing technologies' operating profiles. By applying a techno-economic analysis, investment recovery periods of the considered re-purposing technologies are assessed, which range between two (GtP) and over ten (PtG) years. A sensitivity analysis accounting for current energy prices and technological advancements reveals capital expenditure has the highest impact on this Return-On-Investment period. Additionally, a case study considering the Austrian energy grids is performed to account for the grid impact of integrating these technologies at former CFPP sites. Thus, it is found that the investigated sector coupling technologies have the potential to compensate for grid congestions even in profit-optimised operation.
K E Y W O R D Scoal phase-out, combined cycle gas turbine, energy markets, mixed-integer linear programming, power-to-gas
| INTRODUCTIONCoal represents the most common fossil fuel resource and is the largest source for electricity generation, providing about 37% of the global electricity demand [1]. Additionally, coal electricity generation is considered reliable and cost-effective [2]. However, since coal is also the most carbon-intensive fossil fuel, currently accounting for more than 30% of global CO 2 emissions [3], coal-fired electricity generation is under political and economic pressure [2]. Therefore, the coal phaseout [4] is an inevitable next step for European countries to rapidly achieve climate neutrality of the electrical energy system [4]. To remain within the carbon budget of the Paris Agreement [5], 72% of the CFPPs operating in 2020 within the European Union (EU) have to be shut down by 2025 [4, 6]. While more than 30% of the European countries already have coal-free power generation, the coal phase-out is not even under discussion in 24% of the European countries. A more detailed description of the coal phase-out trends in Europe can be seen in Figure 1. According to the individual national phaseout plans, 63% of the European countries are expected to generate coal-free electricity by 2030 [7].The coal phase-out, however, leads to the early closure of existing coal-fired power plant (coal-fired power plants (CFPP)) sites before they reach end-of-life. Thus, the coal phase-out entails the risk of leaving valuable assets (e.g. infr...
