Peculiarities of designing the power supply system with renewable energy sources in the conditions of the electricity market

Abstract

Due to the formation of the electricity market in 2019, independent producers gained access to the market. This initiative promotes free pricing of electricity costs and in the long run should simultaneously reduce the cost of electricity and ensure the stability of Ukraine's energy system. One of the promising sources of energy that can be sold on the market is renewable energy. At the same time, the owners of power supply systems with renewable electricity have unstable energy generation, which unbalances the unified energy system of Ukraine. Free pricing will help balance the energy system, because at intervals of energy deficit it will have a higher cost. Therefore, energy suppliers from renewable sources will be interested in installing storage capacity in order to accumulate electricity at intervals when it is cheap, and sell at a high cost. The article analyzes the conditions of profitability of power supply systems with and without energy storage system, depending on the level of depreciation and the cost of electricity. In this case, the energy of the power supply system without energy storage is immediately sold to the grid without balancing the system, so it is more appropriate to use a system with storage, which should provide a significant difference in price for periods of energy shortage. It is proved that it is expedient to use one of the cheapest types of renewable energy source in the power supply system. Whereas to reduce the cost of a power storage system with energy storage, it is more appropriate to use several energy sources whose power is weakly correlated. In this case, the storage system has less energy consumption and lower cost. Since the statistics on solar power and wind speed for a particular region are given as an array of numerical data, as a rule, the parameters of the system with the maximum profit are sought by numerical methods, most often - the gradient descent method. In this case, to balance the power system, it is advisable that the profit of the system with energy storage exceeds the profit of the system without it, which is possible provided that the difference between the maximum and minimum price of electricity during the day.