E&WR - Water-Energy Interface
Mine Water for Thermoelectric Power Generation: A Modeling Framework
The purpose of this study, conducted by the National Mine Land Reclamation Center at West Virginia University, is to develop and demonstrate a framework for assessing the costs, technical and regulatory aspects, and environmental benefits of using mine water for thermo-electric power generation. The framework provides a systematic process for evaluating the hydrologic, chemical, engineering, and environmental factors to be considered and evaluated in using mine water as an alternative to traditional freshwater supply. Development and demonstration of the framework involves the following activities:
- A field investigation and case study conducted for the proposed Beech Hollow Power Plant located in Champion, Pennsylvania. This 300 megawatt power plant has been proposed to burn coal refuse from the Champion coal refuse pile, which is the largest coal waste pile in Western Pennsylvania. The field study, based on previous mine pool research conducted by the National Mine Land Reclamation Center (NMLRC), identifies mine water sources sufficient to reliably supply the 2,000 to 3,000 gpm power plant water requirement.
- Development of a water collection, transportation, and treatment system designed around this facility.
- Utilizing this case study, a computer based design aid is developed utilizing the water collection and handling principles derived during the field investigation, and from previous studies of mine water and power plant cooling including information obtained from other power plants using mine water. The cost of using mine water for plant cooling or other plant uses is compared to the cost of using alternate water supplies, including surface water and public water (as currently contemplated in the Beech Hollow power plant design) and river water for other power plant sites. In addition, the potential environmental improvements resulting from the utilization of mine water that is currently contaminating area streams is documented.
Several thermoelectric plants in Eastern Pennsylvania utilize mine waters (from coal and non-coal mines) in their operations. These uses are for non-contact cooling water, coal combustion byproduct conditioning, and for flow augmentation (allowing a power plant to withdraw water from surface water sources while using water pumped and/or discharged from mine to augment stream flow). Because these plants are located in the anthracite coal region, the raw mine water quality is generally acceptable for cooling use and stream flow augmentation with minimal treatment. This is in contrast with the Beech Hollow plant that is located in the bituminous coal region where mine water is of poorer quality requiring additional treatment for surface discharge. In addition, this project will consider the use of ambient mine water temperature to enhance plant thermal efficiency. Also, the anthracite mines that are used in northeastern Pennsylvania are very deep, steeply pitched, with very thick seams resulting in large, deep, and continuous mine voids that can supply the needs of a typical FBC plant from a single mine with minimal collection systems. The Pittsburgh coal seam in the vicinity of the Champion refuse pile is, on the other hand, nearly horizontal, largely above drainage with many relative small mines. In contrasting this project's results with those of the anthracite region applications, the model considers not only the water treatment costs but also the costs of accessing, balancing, and transporting multiple sources to constitute an adequate and continuous water supply to the power plant.