Dispatch Optimization of Solar Thermal Power Plant considering Uncertainties in Weather Forecasts

Kurzfassung

The dispatchability of Concentrated Solar Power (CSP) plants with thermal storage is a key for the upcoming role of this technology on balancing production and demand in electricity markets. In order to achieve an accurate delivery schedule for the following days based on electricity demand and weather forecasts, uncertainties need to be considered. The sources of uncertainty on dispatch scheduling are plural, when considering different market setups and weather forecast methods. Therefore, improvements in uncertainty treatment combined with optimization can increase CSP delivery accuracy. In this context, a dispatch optimizer (DO) was developed that is used to derive a CSP plant schedule for the upcoming 48 hours. It considers weather and electricity pricing forecasts with a special focus on the incorporation of uncertainty associated to the forecasts. A rule-based heuristic optimization was developed which is based on problem-specific considerations. The strategy of the DO is based on a partitioned calculation between the optimization algorithm and the uncertainty processing. The heuristic optimization runs deterministically with all the possible input scenarios, while the uncertainty is dealt as a post-processing. Therefore, the result of the optimization is a range of possible power schedules, and the uncertainty post-processing is able to categorize single schedules suggestions according to the risk of meeting the promised energy delivery. The developed strategy brings the possibility of dealing with several types of weather forecast, such as probabilistic and deterministic, as well as enabling the evaluation of the quality of weather forecast data and its efficiency for optimizing the dispatch. Also, the inclusion of other uncertainty parameters (e.g. economic benefit and operation strategy) and the consideration of penalties are incorporated in the optimization. In conclusion, several delivery strategies can be performed according to the market setup and the decision maker’s point of view.