Energetic and exergetic analysis has been carried out for the components of the solar thermal power plant system (parabolic trough collector/receiver and Rankine heat engine). The energetic and exergetic losses as well as efficiencies for typical parabolic trough concentrating solar thermal power plant (PTCSTPP) under the specific operating conditions have been evaluated. Operating pressures for a Rankine heat engine have been optimized for maximum efficiency. It has been found that, the energetic and exergetic efficiencies of PTCSTPP increased by 1.49% and 1.51% with increasing pressure from 90 to 105 bar respectively. Progression of the STPP from the variable load to full load conditions, the year round average energetic efficiency can be increased from 22.01% to 22.62% for the location of Jodhpur, and in case of Delhi, it can be increased from 20.98% to 21.50%. Year round average exergetic efficiency can be increased, from 23.66% to 24.32% for the location of Jodhpur and in case of Delhi, it can be increased from 22.56% to 23.11%. Land areas required for the 50 MWe thermal power plants are 79.2 ha and 118.8 ha respectively for the locations of Jodhpur and Delhi. (c) 2012 Elsevier Ltd. All rights reserved.