Mine water as a source of energy: an application in a coalfield in Laciana Valley (León, NW Spain)

Abstract

Mine water can be a renewable and economical source of geothermal and hydraulic energy. Nine discharges from closed and flooded coal mines in the Laciana Valley (León, NW Spain) have been studied. Various technologies for the energy use of mine water, as well as the influence of factors such as temperature, the need for water treatment, investment, potential customers and expansion capacity, have been evaluated by means of a decision-making tool. It was concluded that the most advantageous option is an open-loop geothermal system using the waters of a mountain mine, the temperature of which exceeds 14ºC and whose distance to customers is less than 2 km. A district heating has been designed to supply, with technical-economic viability, heating and hot water to six public buildings in the nearby town of Villablino. The proposed use of mine water might help areas that have been greatly affected socio-economically by the closure of the mines and has other intangible advantages compared to conventional systems, such as the reduction of CO2 emissions.