Potential of Solar Thermal Energy Utilization in Electrical Generation

Solar parabolic concentrating collectors are widely and efficiently used in electrical generation. They were experimentally validated in worldwide pioneer plants. SEGS-VI 30 MW solar power plant built in southern California is one of these plants that was commissioned many years ago. In this work a possibility of installing such plant in Makkah, 21.4 °N located in moderate latitudes is studied. The systems collect energy using a synthetic heat transfer fluid pumped through absorber tubes in the focal line of parabolic trough collectors. The heated fluid provides the thermal resource to drive a Rankine steam power cycle. The solar field consists of tracking parabolic trough collectors connected to Rankine power cycle through a preheater, steam generator and superheater respectively. The Rankine cycle is reheated-regenerative cycle with a separate solar field reheats up steam to the low-pressure turbine through separate superheater. Both solar and power cycles were modeled by TRNSYS-17 simulation program. Weather data of Makkah generated by Meteonorm-V5 program are used to simulate the plant performance. The simulation results are successfully validated by hourly measured data of SEGS-VI under the same weather conditions. The annual hourly data are estimated and presented for the plant under the weather of Makkah. It is obtained that the plant is efficient under Makkah weather and its power is improved. The power of the plant is about 34 MW during summer where it is about 26 MW during winter; the plant can produce about 112110 MWh yearly. In addition, the same plant is used as direct steam generation (DSG) cycle. The heat transfer fluid (HTF) is used as water in the solar field. It is seen that the power is widely improved and it is ranged from 45 to 60 MW during winter and summer respectively. The annual generated energy is improved to about 182005 MWh. Finally it is concluded that the solar thermal power plants can play a considerable role for energy generation in Makkah, KSA.