Integration of solar energy into hybrid combined-cycle power generation systems

The paper discusses the issue of solar hybrid combined-cycle power generation systems. Parabolic trough and central receiver technologies are the most suitable solar technologies for hybrid systems using both solar energy and fossil fuel energy. In hybrid systems, solar energy can be used for both air preheating in the topping gas turbine plant and steam reheat in the bottoming steam turbine plant of a combined cycle. Fuel savings and CO2 emissions reduction would be achieved. Direct steam generation in parabolic trough technology, improved materials and advanced central receiver and heliostat designs will enhance the efficiency and improve the cost-effectiveness of solar thermal power systems. However, the real break-through in the commercialization of solar power plants in the near-term will be possible only when solar collector subsystems are integrated into combined-cycle power plants. Performance parameters have been established for both solar power plants and solar hybrid combined-cycle power generation systems. Model calculations predict annual fuel savings of up to 30% and corresponding CO2 emission reductions under favorable climatic conditions and appropriate technology.