Development of a reference concept for a solar-assisted hybrid cycle for the fossil fuel-fired power plant : A Case Study for Syrdaria Thermal Power Plant, Uzbekistan

Kurzfassung

In this study, two options of solar heat integration into an existing gas fired thermal power plant are investigated, namely integration into the last high pressure preheater and into the last low pressure preheater. Simulations of both options are done by using models set up in EbsilonProfessional and performing annual simulations with hourly time steps. Two operational schemes are considered for both options: utilization of solar heat to boost the electricity output or to save fossil fuel and keep the output constant. Comparison of the results from the models with solar heat integration with the results from the model of the fossil reference plant running under the same conditions provides the solar electricity as well as the fuel saving. These results show that integration of solar heat into the high pressure preheater will lead to higher conversion efficiency and higher annual solar output. The net conversion efficiency of solar heat is in the range of 33 to 34% and the economic evaluation based on cost assumptions from literature delivers LCOE values between 9 and 14.5 US ¢/kWh which is comparable to the values for large standalone CSP plants worldwide.