## 2 Materials and Methods
\right., \tag{1}\]  
where \(P_{PV}\)--photovoltaic module power, W; \(I_{PV}^{st}\), current at the output of the automatic voltage stabilizer of the photovoltaic module, A; \(I_{PV}^{st}\)--voltage at the output of the automatic voltage stabilizer of the photovoltaic module, V; \(U_{WT}\)--wind turbine output voltage, V; \(U_{PV}\)--voltage at the output of the MPPT controller of the photovoltaic module, V; \(I_{PV}\)--current at the output of the MPPT controller of the photovoltaic module, V; \(\eta_{PV}^{st}\)--the efficiency of the voltage stabilizer of the photovoltaic module; \(I_{ph}\)--photocurrent of solar cells, A; \(I_{0}\)--reverse saturation current of solar cells, A; \(q\)--electron charge, (1.602\(\cdot\)10\({}^{-19}\) C); \(R_{s}\)--series resistance of solar cells, Ohm; \(A\)--the ideality factor, depending on the thickness of the p-n-junction and the material, takes values for a silicon solar cell from 1.2 to 5 (Table 1); \(k\)--Boltzmann constant, (1.381\(\cdot\)10\({}^{-23}\) J/K); T--absolute solar cell temperature, K; \(I_{sc\left(stc\right)}\)--short-circuit current of the solar cell under standard conditions, A; \(K_{i}\)--temperature coefficient of the short-circuit current of the solar cell, A/K; \(K_{u}\)--temperature coefficient of no-load voltage, V/K; \(K_{t}\)--temperature coefficient of temperature rise, (K-m\({}^{2}\))/W; \(T_{stc}\)--temperature standard conditions, (298 K); \(n_{s}\)number of solar cells connected in series; \(T_{env}\)--ambient temperature, K; \(U_{id\left(stc\right)}\)--open circuit voltage of the solar cell under standard conditions, V; \(IR\)--value of the intensity of solar radiation, W/m\({}^{2}\); and \(IR_{stc}\)--solar radiation intensity under standard conditions, (W/m\({}^{2}\)). The block diagram of the electrical part of the power plant is shown in Figure 2. The principle of operation is as follows: electrical energy from the alternating current generator of the wind turbine (1) through the charge controller (6) is transferred to the storage battery (7). In this case, the conversion of alternating voltage to direct voltage is carried out by means of a rectifier (2). The electrical energy from the photovoltaic system (5) is also transferred to the battery through the charge controller. At the same time, in order to ensure efficient extraction of electrical energy, using the MPPT controller (4), an energy extraction mode is set corresponding to the maximum power point of photovoltaic converters and voltage matching is performed by means of a stabilizer (3). The voltage regulator and the charge controller are controlled by a microcontroller device (9). Electric energy from the battery is transmitted to the consumer through the inverter (8), which converts DC voltage into AC voltage. We carried out a digital aerodynamic simulation of the operation of the Darrieus rotor of a wind turbine with three blades with NACA 0021 profiles using the finite volume method [36]. A 2D computational domain with a length exceeding the rotor diameter by a factor of 5 has been developed, which makes it possible to obtain the parameters of the flow around the rotor with an accuracy sufficient for engineering calculations. To speed up the calculations without reducing the accuracy of their results, the computational domain