Review of Geothermal and Solar Thermal Power Plants and a Comparative Design Analysis

Abstract

Thermodynamics indicates that the lower the temperature of a resource, the less energy that could be extracted from it due to lower maximum thermal efficiency. Geothermal resources exist in varying temperatures. The lowest ones (around 120°C), are too small for economic power production. On the other hand, concentrating solar power (CSP) can achieve high temperatures during the day (from 350 to 550°C, based on a Parabolic Trough CSP plant [1]) but once the sun is not shining, that temperature is reduced drastically. Transition to renewable energy systems is an environmentally friendly and potentially rewarding economic decision that society can make nowadays. This paper briefly reviews geothermal and solar thermal based plants in terms of energy growth or decay from one year to another (2012–2013). In addition, an example site location is chosen and the performance of both these types of power plants is analyzed in terms of capacity factor, Thermal Energy Storage (TES) hours, solar multiple, area requirement and Levelized Cost of Energy (LCOE) for a given set of environmental conditions. This analysis is performed using the System Advisor Model (SAM), on which simulation of parabolic trough, power tower, linear Fresnel, dish Stirling and geothermal (binary cycle) energy conversion systems are considered. At the same time, the analysis discussed will take place in a further study which will include economic viability for the two technologies running under the same combined cycle.