The planned increase of the share of renewable energy brings new challenges in power systems. For instance, the contribution of wind and solar energy generation to the overall reliability of systems and to the provision of sufficient capacity needs to be examined. While the specific factors of availability for conventional power generation technologies are known, the availability factors of renewable sources such as wind and solar energy depend on wind speed and solar radiation at specific locations. Due to the volatile nature of wind and solar energy it is very difficult to accurately determine the level of additional operational reserves to ensure reliable operation of the electricity system and the continuity of supply to customers. Hence the main objective of this work is to develop an appropriate model for the analysis of the reliability of power supply with incorporated renewable energy sources.
For reliability assessment the sequential Monte Carlo simulations are used. Their main advantage is that they take into account the chronological sequence of events and the stochastic nature of the systems, which is essential in assessing the reliability of electric power systems with incorporated time-dependent and correlated renewable energy sources. Modelling wind and solar energy requires a lot of historical wind and solar energy measurements in order to successfully capture the stochastic nature and random behavior of solar and wind energy at specific locations. In most cases, such data are inaccessible, so we can use simulation techniques which preserve the main features of the initial measurements. The Markov chain technique is presented to simulate time series of wind and solar energy. It preserves the main features of initial measurements such as tracking the monthly patterns of solar and wind energy and autocorrelation. The presented method allows to develop different scenarios with changing proportions of integrated solar, wind and conventional energy sources in the total installed capacity of systems. It also allows to calculate different reliability indices, which makes it a useful tool for the design of power systems.
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