Influence of Wind and Solar Power Plants on the Reliability of the Functioning of Power Systems

Currently, the world energy uses 318 million kW of wind turbines and about 142.4 million kW of solar power plants, of which the main countries of Western Europe account for about 227 million kW, or 49.3% (for the location of these power plants by country, see Table 1).

Table 1:Use of wind and solar power plants in Western Europe in 2018.

From the presented data, it can be seen that on average in Western Europe, wind and solar power plants account for almost 30% of the total generating capacity, with the largest share of wind turbines in Denmark (47%), and the highest share of solar power plants (18.6%) belongs to Germany.
A modern wind turbine contains a direct generator, an energy storage device (battery) and an inverter. If the offshore wind turbine is provided, then the power plant includes a HV cable for connecting the generator with the high-voltage electrical network of the power system. When assessing the reliability of wind power plants and solar power plants, it was taken into account that wind turbines, as a rule, must operate without maintenance continuously for at least 15 years. The same rule was conditionally extended to the RES. Reliability indices of wind turbines and solar power plants obtained by the analogous calculation method are shown in Table 2.

Table 2:Estimated indicators of reliability of wind and solar power plants.

To study the influence of wind and solar power plants on the reliability of the functioning of power systems, the author’s model of the reliability of power systems “SATURN” in version 3.3 was used.
The studies conducted allow us to draw the following conclusions:
A. An increase in the share of wind and solar power plants in energy systems determines the economy of fossil fuel and reduces harmful emissions into the atmosphere.
B. The same factor causes a decrease in the reliability of the power system, increases the likelihood of systemic accidents with disconnecting consumers and causing them serious economic damage, reaching 1% of the produced GDP
C. This damage can be prevented by increasing the rotating reserve within the available EPS reserve, which will require an increase in funds for its maintenance due to additional fuel consumption.
The ratio of reducing the probable damage to consumers and the cost of additional fuel consumption to maintain the necessary rotating reserve in the power system makes it possible to economically substantiate the strategy and scale of introducing renewable energy sources into the electric power industry.