Probabilistic Performance Assessment of Autonomous Solar Wind Energy Conversion Systems (Rania Ramadan - American University of Beirut, Faculty of Engineering and Architecture - 1998-99)

In this work, several wind-solar energy conversion systems were modeled and assessed using probabilistic techniques.

The first system consists of several wind turbines (wind farm) connected to a load and a battery storage. The wind farm may contain identical or different wind turbine classes. The modeling of the system was based upon a comprehensive procedure to estimate the joint probability distribution function of the total available wind power and that of the turbines operating modes due to hardware failure. A methodology was developed to use the proposed model to determine an upper limit on the size of the battery storage required for a given number of turbines to satisfy the load with a certain expected energy not supplied.

The second system is composed of wind farm, several photovoltaic modules (solar park), and a battery storage feeding a load. The model takes into consideration outages due to the primary energy fluctuations and hardware failure, and the dependency between the energy resources and the load. Methodology was developed to determine an upper limit on the size of the battery storage required to satisfy a given load profile taking into consideration the charging/discharging of the batteries.

The third system comprises several diesel units, wind farm, solar park and battery storage feeding a load. The model allows the simulation of a diesel system with a solar-wind farm considering system stability, outages due to hardware failure and primary energy fluctuations. It is based on a modification of the convolution method, which considers a given penetration level selected by the utility for stability consideration. The production costs of the diesel units are then deduced from the expected energy not supplied using a unit de-convolution in reverse economic order. A methodology is also presented to determine the size of the battery storage based on the excess wind energy available during operation, or that disconnected for stability consideration, while accounting for the charging/discharging cycles.