Optimization model for variable renewable energy sources generation: Macedonian case study

Abstract

This paper is motivated by a large tendency of shift towards low emission electricity production, which can be achieved by substituting the conventional energy sources by renewable energy sources. Therefore, a share of renewable energy sources is continually growing. However, large-scale integration of renewable energy sources into the power system is a challenging task, since it depends on a balance between demand and supply at any time and because of the nature of renewable energy sources. The production from some sources such as the photovoltaic and wind power plants fluctuates depending on meteorological conditions, so it cannot be regulated. However, large hydropower plants can be regulated, so they are suitable for electricity balancing. In this paper, an optimization model is set for a system with 100 % renewable energy sources, which includes models for correlation of meteorological data and the production of electricity from different variable renewable energy sources. The resulting model gives an optimal ratio of production of variable renewable energy sources, which depends on the share of these sources in the total electricity production. The objective function of this optimization problem is to minimize the excess and lack of electricity production. For this purpose, hourly data for electricity consumption and hourly meteorological data are included. The results show that if only wind and photovoltaic power plants are considered, for the case of Macedonia, this optimum is found at 72% wind and 28% photovoltaic power production. However, if the already installed capacity of the big hydropower plants and the maximal potential of the small hydropower plants which make together 30% of the total installed capacity is taken into account, the optimal ratio of production from the other sources is: 50% wind power generation and 20% photovoltaic power generation.