Valuation and estimation of geothermal electricity production using carbon dioxide as working fluid in the south of Algeria

The control of carbon dioxide emissions will not result from only one technology but from a whole means deployed simultaneously. This process is not only the development of energies without carbon, but also the control of fossil energies emissions, whose reserves are too significant so that they are forsaken. In Algerian Southern, geothermal resources have a low enthalpy (temperature <= 100 degrees C). They are intended for the direct use such as greenhouse heating and home heating. Geothermal energy could also be used in electricity production by the using an organic fluid. In this study, thermodynamic cycle is considered for the electricity production by geothermal power station which transforms fluid thermal energy into mechanical energy, then into electric power thanks to a generator. Carbon dioxide CO2 is a suitable working fluid (no explosion risks, non-flammable, and non-toxic) where it is vaporized in contact with the geothermic heat, and then it passes in a turbine to generate electricity. An operating analysis is carrying out in order to optimize electric production system. The results obtained gives us a good comprehension of various parameters effect on the electric output such as geothermic gradient, well depth, rock permeability and the well diameter. (C) 2013 The Authors. Published by Elsevier Ltd.