Concentrating solar power tower technology: present status and outlook

The paper examines design and operating data of current concentrated solar power (CSP) solar tower (ST) plants. The study includes CSP with or without boost by combustion of natural gas (NG), and with or without thermal energy storage (TES). Latest, actual specific costs per installed capacity are high, 6,085 $/kW for Ivanpah Solar Electric Generating System (ISEGS) with no TES, and 9,227 $/kW for Crescent Dunes with TES. Actual production of electricity is low and less than the expected. Actual capacity factors are 22% for ISEGS, despite combustion of a significant amount of NG exceeding the planned values, and 13% for Crescent Dunes. The design values were 33% and 52%. The study then reviews the proposed technology updates to improve ratio of solar field power to electric power, capacity factor, matching of production and demand, plant's cost, reliability and life span of plant's components. Key areas of progress are found in materials and manufacturing processes, design of solar field and receiver, receiver and power block fluids, power cycle parameters, optimal management of daily and seasonal operation of the plant, new TES concepts, integration of solar plant with thermal desalination or combined cycle gas turbine (CCGT) installations and specialization of project.