Waste heat problems and solutions in geothermal energy
All heat-power conversion systems produce waste heat, which can attain significant portions. This applies to geothermal power generation too; the waste heat fraction depends on the conversion technology. The more of the waste heat that can be utilized for some useful purpose (and consequently requiring less heat to be rejected), the better economy can be achieved, besides benign environmental effects. The best solution to avoid discharge to the atmosphere or to the hydrosphere is cascaded use. This consist of a chain of applications with stepwise decreasing temperatures, for example, from industrial uses through balneology down to fish farming. Constraints given by environmental legislation can lead to beneficiary solutions like in the case of warm tunnel waters in the Swiss Alps: these would need cooling ponds/towers before being permissible for discharge into local rivers. It is described by several specific examples how the tunnel waters can be used instead.
Figures & Tables
Energy, Waste and the Environment: a Geochemical Perspective
This book provides incentives for further development of sustainable fuel cycles through a novel and interdisciplinary approach to an Earth science-related topic. The main focus is on geochemical concepts in immobilizing, isolating or neutralizing waste derived from energy production and consumption. The book also addresses the issue of using some types of energy-derived waste as alternative raw materials. Moreover, it highlights research on how certain wastes can be used for energy production, an increasingly important aspect of modern integrated waste management strategies. The main objectives are to: (a) identify the most serious environmental problems related to various types of power generation and associated waste accumulation; (b) present strategies, based on natural analogue materials, for the immobilization of toxic and radioactive waste components through mineralogical barriers; (c) discuss modern procedures for reuse of waste or certain waste components; and (d) review the importance of geochemical modelling in describing and predicting the interaction between waste and the environment.