Energy export from wind farms

Energy export from wind farms

In the era of global warming and the growing need to use renewable energy sources, resulting from the rising prices of CO2 emission certificates, renewable energy sources are gaining in importance. Wind farms are one of the most popular and ecological solutions that will contribute to meeting the growing demand for electricity. In this article, we will look at the process of energy export from wind farms, focusing on the construction of wind farms and transmission technology.

Construction of wind farms

Before we move on to the process of energy export from wind farms, it is worth understanding how wind farms work and what components they consist of. The construction of wind farms is based primarily on wind turbines that generate energy from the air movement. Each wind turbine consists of several key components:

1. Tower

The tower on which the rotor is mounted can be from several tens to over two hundred meters high. The higher the tower, the stronger and more stable the wind, which translates into higher efficiency.

2. Rotor

The rotor is a set of blades that are moved by the wind. It usually consists of three blades made of light and durable materials, such as fiberglass, carbon fibre or aluminium. The length of the blades can reach several tens of meters. Wind turbine designers strive to optimize energy efficiency by adapting the design and parameters of turbines to local wind conditions. This includes selecting the appropriate rotor blades, modifying the shape and balance of the turbines, and adjusting the control systems. All this is aimed at maximizing active power generation at various wind speeds and changing weather conditions.

3. Generator

The main component of converting wind energy into electricity is the generator. When the wind moves the rotor blades, this movement is transmitted to a generator that converts kinetic energy into electrical energy.

Energy export from wind farms

The energy export from wind farms consists of several stages, which include the transmission of electricity from the generator to end users.

1. Voltage transformation

After generating electricity in the generator, the voltage must be raised with the help of a transformer. Thanks to this, it is possible to effectively transmit energy over longer distances, minimizing losses resulting from the resistance of wires.

2. Distribution network

Electricity from wind farms is sent to the distribution network via high voltage lines or cables. These grids are responsible for distributing energy over longer distances, connecting wind farms to local power grids. In distribution systems, especially in the case of wind farms, an important aspect is the compensation of reactive power generated by cable lines that are responsible for the energy export from wind farms. With the increase in the length of the HV cable line, the generated capacitive reactive power of the cable increases, which can lead to problems with power quality, transmission efficiency and, above all, additional fees for the Distribution Network Operator. Therefore, it is crucial to use appropriate solutions to compensate for reactive power so that the value of reactive power at the connection point is equal to zero. Various devices are used for this purpose, such as static compensators (STATCOM) and chokes.

3. Local power grid

Wind energy, already at the right voltage, reaches the local power grids, which are responsible for the direct supply of energy to end users, such as households, enterprises or public utility facilities.

4. Collection of produced energy

The last stage of the energy export from wind farms is its use by end consumers. Depending on the energy needs of individual users, wind energy can be used to power household appliances, lighting or industry.

With the growing popularity of renewable energy sources, there are also new challenges when it comes to energy export from wind farms. In some regions where there is a large number of prosumers, i.e. consumers who produce electricity using photovoltaic installations, it may happen that the energy produced goes from the distribution network to the transmission network.

This phenomenon results from the fact that local power grids to which prosumers are connected do not have the capacity to receive the energy (large self-consumption from their generation sources), so excess energy must be transferred to the transmission grid. This is particularly evident in the case of wind farms, which generate more electricity than is needed in the local power grid.

This situation can have a negative impact on the stability of the power grid, as it can lead to grid overload and energy imbalance in the system. Therefore, power grid operators take measures, such as regulating the power generation from wind farms, to prevent network overloads in the National Energy System.

In such a situation, it is important to ensure proper coordination and planning for the development of energy infrastructure, such as smart grids, which can help manage wind energy efficiently and prevent grid congestion.

Energy from wind farms - storage