Modelling, Simulation and Assessment of Solar Thermal Power Plants: A First Step Towards Definition of Best Practice Approaches

With 620 MW_el in operation [1] and more than 2.000 MW_el under construction, concentrated solar power (CSP) experiences a renaissance mainly in Spain and the USA, but also in many other countries in the earth’s sunbelt. Due to their large capacity (50 MW_el and more) and thus large investment, CSP projects are characterised by an extensive project development process. In several stages of this process, mathematical models of the system predicting its energy yield are required, among others to: • assess single CSP projects (e.g., feasibility or due diligence studies), • compare different CSP concepts (e.g., technology, site), • optimise a project (e.g., solar field size, storage capacity), • investigate the influence of component characteristics (e.g., receiver characteristics), • optimise the operation strategy (e.g., on-line surveillance) or to • assess system performance during commissioning. The models used for these different tasks differ in complexity and accuracy, e.g. the accuracy of a model used for project assessment during commissioning has to be higher than a model used for a pre-feasibility study. At the moment, numerous modelling approaches exist and every project developer uses his own system model and assessment methodology. This confusing situation hinders the acceptance of CSP technology by potential investors. This paper presents a methodology for structuring systems into sub-systems. This is the first step towards a standardized modelling approach for CSP systems. It is not the intention of the authors to present a final model and assessment methodology but to start a broader discussion on this important topic. In fact, it aims at initiating an international working group, devoted to the definition of guidelines for modelling, simulation and assessment of CSP systems, covering all CSP technologies such as solar towers, parabolic troughs, linear Fresnel collectors and solar dishes.