This paper presents the possibilities of adapting active mines to generate green energy after their closure using their resources and/or infrastructure. For this purpose, firstly, the temporal horizon of selected mines in Poland was determined, its basic assumption being the analysis of the current state. In the research, 18 mining plants operating within 12 mines in the Upper Silesian Coal Basin (USCB) were analyzed. The analyzed mines belong to three of the five largest hard coal producers in Poland, and the main object of exploitation is hard coal of energy types. Severe restrictions or even abandonment of further investments in the development of the coal mining industry were taken into consideration (regarding the construction of new shafts or the development of new exploitation levels). When determining the temporal horizon, the challenges that hamper the exploitation based at the levels of natural hazards and depth of exploitation in each mine were considered. Secondly, the criteria for the adaptation of active mines to generate energy are presented. The possibility of using the resources and infrastructural potential of active mines to produce geothermal energy from water, extracting coalbed methane (CBM), and processes of underground coal gasification (UCG) are analyzed. Finally, for a selected example—generating energy from underground coal gasification in Polish mine conditions—a structural analysis of the criteria was performed using the MICMAC method, as the Central Mining Institute has an extensive experience in the development of underground coal gasification trials in coal mines. Based on expert analysis and using structural analysis, the criteria important for UCG were selected. As demonstrated in the article, the MICMAC method can be applied in other scenarios with different criteria to implement new technologies in coal mines.

The closure process of underground coal mines entails specific risks which require a careful liquidation methodology, including the implementation of relevant risk mitigation procedures to identify the key hazards to the environment and humans. As gas represents one of the major risks, it needs to be taken into consideration in the liquidation process. Given its adverse effect on the environment, methane, a greenhouse gas, requires particular attention and may also reach dangerous concentrations in the ground floor areas and basements of buildings as well as in areas where mine closure works are conducted, leading to intoxication, asphyxia or explosions. This paper presents a risk analysis of the methane hazard occurring at the final stage of the closure process of a Polish underground mine. It applies a methane emission model created jointly by the National Institute for the Environment and Industrial Hazards (INERIS) in France and the Central Mining Institute (GIG) in Poland. The analyses and measurements carried out for this paper were conducted within the framework of the Management of Environmental Risks during and after Mine Closure (MERIDA) project. The subject of the study included: the flooding process and how it affects the scale of gas emission from goafs, changes in methane concentration, and changes in the volume of voids.

Mining companies are responsible for the impacts that result from their mining activities even after the mining period has ended. At the same time, at the European and international levels, there is a lack of a detailed operational methodology comprising environmental risks during and after closure of underground coal mines. The environmental risk aspects that need to be considered when planning the closure of an underground coal mine and post closure in the broader environmental context are the following: modification of water flow scheme, surface instability, mine gas emission on the surface, and water and soil pollution. In this study, we focus on assessing groundwater risk in the context of an underground coal mine closure and evaluating the selected risk mitigation strategies in terms of performance and cost. The results from this study could be used for developing a final closure groundwater assessment plan by selecting the most feasible treatment alternatives for different environmental impacts, together with the transitional monitoring that could guarantee a hazard level in compliance with land reuse and the use of natural resources. Finally, the cost-efficient monitoring and treatment programs are used to estimate the financial provisions needed to mitigate groundwater risks during underground coal mine closure contexts.