Определение экономических показателей автономного энергокомплекса на базе ГТУ, ВЭУ и электрических аккумуляторов

Abstract

In order to ensure high efficiency of natural gas use, increase the reliability and quality of energy supply, it is necessary to introduce alternative energy sources and electric accumulators into the classic GTU energy generation schemes. In this regard, the object of research is a combined autonomous source based on a gas turbine unit (GTU), a wind-driven power plant (WDPP) and energy storage. Energy production at wind turbines is conventionally divided into two stages (day and night), during the day energy is supply into the grid, and at night it is stored in energy storage. The purpose of the article is to determine the economic indicators of this variant of the scheme for combining sources of different types of generation. To determine the effectiveness of the source, a mathematical model was developed with the help of which quantitative and economic indicators are calculated. Initial data: daily schedule of electric loads, average monthly temperature and wind speed, dependence of changes in the electric power of WDPP on wind speed in relative units. According to the presented method, quantitative and economic indicators were calculated, which investigated the impact of changes in the installed capacity of WDPP (200 kW – 1400 kW) on changes in economic indicators: discounted costs, net present value, discounted profitability index (DPI), internal rate of return (IRR) and payback period. The annual output of electricity and heat is stable and amounts to 20409 MWh/year and 239970 GJ/year, respectively. In the publication, a comparative analysis of the obtained economic indicators was made. Discounted costs, despite the decrease in the installed capacity of the GTU, increase as the installed capacity of the wind turbine and energy storage increases. Economic efficiency is reduced, which is reflected in an increase in the payback period and a decrease in the NPV. The reason for this low efficiency is the high unit cost of wind turbines and energy storage. From the results obtained, it can be concluded that the lower the installed capacity of the wind turbine and, accordingly, the energy storage, the higher the economic indicators. At this time, the use of such combinations (GTU, WDPP and energy storage) is beneficial only if the share of the installed capacity of the wind turbine does not exceed 45% of the gas turbine capacity.