Comparative Exergetic Analysis of Solar Integration and Regeneration in Steam Power Plants

Nowadays, many health, environmental, and economic concerns are associated with fossil fuel use, and therefore the improvement of new and advanced technologies and the use of renewable fuels are key issues for the sustainable development of the planet. The aim of this research is the plan of new power systems for future urban centers rising on reclaimed industrial areas; an innovative and convenient mode to exploit the solar energy is proposed using solar thermal power to replace the bled-off steam in regenerative Rankine power cycles. The main idea is the concept that exploitation of solar power in solar thermal–aided power-generation plants can be more cost- and energy-effective than using it in exclusively solar plants, especially in medium-temperature systems. For this purpose, the paper deepens an investigation about biomass-solar combination in a regenerative Rankine cycle system with superheating, substituting the steam bleeds by solar power for feed water preheating process. In biomass-solar combined configuration, the conversion efficiency of solar energy is appraised to compare the exploitation of solar energy in power plants characterized by different plant configurations. The calculated global and exergetic efficiencies are assumed as optimization factors for the best plant configurations, changing regeneration parameters and steam pressure.