Optimized Hybrid Renewable Energy System for a Baseload Plant

Abstract

The objective of this paper is to proof that intermittent renewable supply sources can be integrated to develop a reliable baseload plant, which can generate electricity at a competitive cost to the conventional generation. A methodology has been developed to optimize the design of a hybride plant, which is based on several technologies including; solar PV, wind, hydrogen generation/fuel cells, and batteries to serve as a renewable energy baseload plant. The methodology includes site selection to ensure maximum integration among the intermittent supply sources as well as optimized sizing of both generation and storage technologies. The objective function is for the least Levelized Cost of Energy (LCoE). The system reliability is judged using the Loss of Power Supply Probability (LoPSP) criterion. A MATLAB algorithm has been developed for the initial sizing of the system components, which searches for the optimum solution within the applicability domain. This is followed by HOMER software-based optimization technique for the plant operation. A case study for baseload hybrid plant of a capacity 200 MW is presented. The location of the plant is screened among several sites in Egypt to achieve the best optimum combination of both solar and wind generation considering; resource intensity, site conditions and constraints, as well as integration between solar PV and wind outputs. According to the selected site and according to the developed optimization methodology, the system has a combination of renewable generation/storage capacities of; 87.5% wind and 12.5% solar PV, and storage of 75% fuel cell and 25% battery. This injects energy to the grid with an energy mix of 89 % from direct renewable power sources (solar PV & wind), 8 % from the fuel cell, and 3 % from the battery. This energy mix ensures a steady output baseload of 200 MW throughout the year with zero LoPSP, at a LCoE of 8.61 ¢/kWh. Relaxing the LoPSP constraint to 2.5% resulted in 26.83% reduction in the LCoE to 6.8 ¢/kWh. According to this study, renewable energy generation can be used toward achieving 100% baseload power systems at competitive energy cost to the conventional generation.