Reliability Availability and Maintainability Study for Concentrated Solar Plants and how to account for current limitations and challenges
Sunlight is an abundant resource, nothing else across the renewable’s spectrum generates such high expectations for investment as the potential of directly harnessing the power of the sun. Designers and operators are carrying out reliability studies essentially to optimize project profitability as a function of income and expense factors such as capital expenditures, operating expenditures, production rate, the frequency of equipment failures and the associated downtime for such failures. Reliability Availability and Maintainability (RAM) studies are used to predict system availability, identify ways to improve system availability, throughput performance and the efficiency of solar plant from a cost/benefit point of view. The models generated require data to predict capacity as in uptime or revenue profile forward. Reliability expressed in Mean Time Between Failures and Maintainability expressed as the average time to return failed item to service (Mean Time to Repair) are based on rule sets and assumptions for different technologies. Component data is provided by the suppliers (e.g. laboratory testing/inspection), rather than years of operational excellence, as the industry is not as mature as conventional power plants. The sun’s intermittency of power output affects the investment requirements to distinguish between installed capacity and electricity actually generated due to unpredictable nature of solar radiations. Tower-based Concentrated Solar Plants (CSP) holds out the advantages of thermal energy storage while the solar field is available only during the day. These constraints needs to be adequately captured in the analysis in order to assess the reliability and energy contribution of the solar system to meet overall system demand. A particular case study is presented for a CSP facility.