Cascade utilization of low and medium enthalpy geothermal resources A - review

This paper mainly presents a comprehensive review in different regions around the world about the use of geothermal resources of medium and low enthalpy in cascade manner. The utilization of geothermal resources in cascade levels is identified as a mean of sequential operation of geothermal heat by integrating different technologies for electricity generation, distribution and use of thermal energy, drying and dehydration processes, recreational uses, and any other direct-use of geothermal heat. Particularly, this review identifies cascade systems that have been implemented in a practical manner and conceptual systems that have been studied to determine their technical and economic feasibility. It is also observed the recent or in progress research that aims to demonstrate the advantage of using geothermal energy in cascade mode in order to maximize the use of geothermal resources in a rational and sustainable manner. The main features of the systems reported are highlighted, describing briefly the technologies used for these types of systems, temperature of geothermal resources, investment costs, methods of analysis and the main advantages and disadvantages. Finally, a discussion and some remarks are presented stating in general, that the use of geothermal energy in cascade is an effective and sustainable approach to promote the use of geothermal resources of medium and low enthalpy. (C) 2015 Elsevier Ltd. All rights reserved.