Integrated Analysis of Dispatchable Concentrated Solar Power

Abstract Many countries in the world investigate the role of concentrated solar power for the future electricity generation. The technology bears many advantages in comparison with other renewable energy sources, as it can be combined with thermal energy storage and can thus be used to supply peak electricity and provide a higher flexibility and dispatchability. Availableconcepts differ in terms of energy yield, degree of dispatchability and levelized cost of electricity generation. Moreover, the possible contribution of CSP plants to grid security remains often unclear. For the example of South Africa, a booming economy with ambitiousclimate protection targets, we demonstrate the applicability of aninnovative method to analyse the future role of concentrated solar power with and without storage. Based on a calculation of energy yield and energy provision characteristics and a probabilistic reliability method we show that storage capacity substantially affects firm capacity. Results show that depending on the additional CSP capacity and storage configuration which is added to the energy system, capacity credits range from 22% to 34% for systems without storage, 47% to 69% for CSP plants with limited storage and 84% to 93% for configurations with an extended storage configuration. Using an integrated energy system optimization model, we identify that CSP with appropriate storage size is a suitable option to cost efficiently mitigate greenhouse gas emissions. In an ambitious GHG mitigation scenario for South Africa, CSP would be one of the most important mitigation measures, providing about one quarter of the total electricity in future. The results also show that it is crucial to consider the share of renewable firm capacity through the future procurement of CSP capacity with appropriate storage size in future energy planning.