Optimisation of power consumption modes for an autonomous electrical system with renewable and alternative energy sources

A mathematical modelling study was carried out in order to optimise power generation modes for an autonomous electrical system using alternative energy sources. The object of modelling research involves the regional autonomous electric power system of the Gorno-Badakhshan Autonomous Province (Republic of Tajikistan). Minimisation of financial costs for auxiliary power consumption, as well as their maximisation from the sale and redistribution of electricity flows, was chosen as the target function. Optimisation of energy consumption costs per each hour of the daily interval was carried out by the method of linear programming and "If…, Then…" production rules with taking into account the following restrictions on the capacity of renewable energy sources: ≤ 43.5 MW hydroelectric power plants; ≤ 10 MW wind farms; ≤ 6 MW solar photovoltaic station; ≤ 5 MW energy storage units. As a result, a methodology and corresponding algorithm for the optimisation of power consumption are proposed to minimise the financial costs to individual power consumers having a choice of power supply from renewable (hydro resources) and alternative (wind flow and solar insolation) energy sources, including an energy storage device. At the same time, the maximisation of financial income from the sale and redistribution of electricity flows is considered. The optimal ratio of energy generation by the alternative sources, comprising hydroelectric power plant, wind farms, solar photovoltaic station and energy storage unit from the daily electricity consumption in the winter period was determined to be 94.8, 3.8, 0.5 and 0.8 %, respectively. The energy storage capacity varied from 2-5 MW. In the summer period, it was shown that the optimal choice of generation sources is the energy generated by the region's hydroelectric power plant due to its being lowest in cost. Depending on the selected alternative and renewable energy sources, a system analysis of the results obtained showed the possibility for each generating consumer to independently minimise their electricity costs and maximise incomes from mutual energy exchange with other consumers.

autonomous electrical system, optimization of power consumption, renewable energy sources, energy storage devices, generating consumer, wind turbine