Modular Hybridization of Solar Thermal Power Plants for Developing Nations

Abstract:

The current energy scenario in the developing nations with abundant sun resource (e.g. southernMediterranean countries of Europe, Middle-East & North Africa) relies mainly on fossil fuels to supplythe increasing energy demand. Although this long adopted pattern ensures electricity availability ondemand at all times through the least cost proven technology, it is highly unsustainable due to its drasticimpacts on depletion of resources, environmental emissions and electricity prices. Solar thermal Hybridpower plants among all other renewable energy technologies have the potential of replacing the centralutility model of conventional power plants, the understood integration of solar thermal technologies intoexisting conventional power plants shows the opportunity of combining low cost reliable power andCarbon emission reduction.A literature review on the current concentrating solar power (CSP) technologies and their suitability forintegration into conventional power cycles was concluded, the best option was found be in the so calledIntegrated solar combined cycle systems (ISCCS); the plant is built and operated like a normal combinedcycle, with a solar circuit consisting of central tower receiver and heliostat field adding heat to thebottoming Rankine cycle.A complete model of the cycle was developed in TRNSYS simulation software and Matlab environment,yearly satellite solar insolation data was used to study the effect of integrating solar power to the cyclethrow-out the year. A multi objective thermo economic optimization analysis was conducted in order toidentify a set of optimum design options. The optimization has shown that the efficiency of thecombined cycle can be increased resulting in a Levelized electricity cost in the range of 10 -14 USDcts/Kwhe. The limit of annual solar share realized was found to be around 7 %The results of the study indicate that ISCCS offers advantages of higher efficiency, low cost reliablepower and on the same time sends a green message by reducing the environmental impacts in ourexisting power plant systems.