The ABC’s of Renewable Energy: How do large wind turbines work?

When visiting beautiful coastal areas in Estonia, powerful and magnificent wind turbines catch our eyes in many places. But how do the wind turbines we see in Virtsu, Paldiski or Aulepa operate?

Gearboxes are not just for cars

The principle of operation of wind turbines is quite simple. Three aerodynamically designed blades trap moving air and use it to generate electricity.

Externally, a wind turbine consists of two components – rotor blades and nacelle. Inside the nacelle are shafts rotating at various speeds, a generator, and a gearbox between them. The wind makes the rotor blades rotate, which in turn causes the shafts inside the wind turbine to rotate. These then start the generator, the electricity from which is transmitted to the energy converter. The task of the latter is to adjust the energy for wider use.


Four criteria help determine the amount of electricity generated by wind turbines. These are power, wind speed, blade radius and air density. Before installing a wind turbine, you must first review the planned location and its wind conditions.

The power of the wind turbine and the dimensions of the blades are chosen according to the generation needs. High wind turbines are the most efficient, catching moving air masses more strongly and stably than smaller ones.

The myths regarding wind turbines are not worth believing

There's a myth about wind turbines that the stronger the wind, the more electricity is generated. In reality, wind turbines are switched off when the wind speed exceeds 25 m/s, as this can lead to over-generation of electricity and damage to the wind turbine. The blades start working at 3.5 m/s and the optimal wind speed for them is 12-13 m/s. This is the case if the system is set up according to the environmental conditions of the specific area.

There is a global increasing trend towards cleaner electricity production, meaning a very bright future for wind energy. The technology is becoming cheaper and evolving at the same pace, which, as in Estonia, may soon lead to the establishment of new wind farms, helping to achieve climate neutrality. According to Eesti Energia, there could be at least one offshore wind farm in Estonia by 2030.

Home garden wind turbines may become widespread in the future, but the implementation of such technology at the moment is too expensive for private consumers.

At the end of last year, there were a total of 139 operating wind turbines in Estonia which generated a total of 590 GWh of electricity over the year, accounting for more than 1/3 of total renewable energy output.