According to the current legal framework, the generation of electrical energy from wind turbines is supported with the following feed-in-tariffs:

Regarding the licensing procedure:

Wind turbine installations with installed power smaller or equal to 100 kW are excluded from the obligation to receive a license for electrical energy generation and also from the obligation to receive an installation license and an operation license. (Law 3851/2010 article 2, par.12 and article 8, par.13)

Wind turbines installed in buildings or other structures or in organized industrial areas are excluded from the obligation to receive an environmental license. (Law 3851/2010 article 8, par.13)

Wind turbines installed on field sites with installed power not exceeding 20 kW are excluded from the obligation to receive an environmental license. These installations are required to receive a certificate which confirms the exclusion from this obligation by the appropriate environmental authority. (Law 3851/2010 article 8, par. 13)

The following wind turbine power plants belong to the environmental category B (OGG 21B_2012):

All wind energy power plants with installed power   20 kW < P < 5 MW and also those with installed power P < 20 kW when also the following conditions apply:

a)  They are installed on fields which belong to the Natura 2000 network or in areas with distance less than 100 meters from the sea.

b)  They have a distance less than 150m with another wind energy power plant which is installed on a field site and has an issued electrical energy generation license.

The licensing procedure for those projects that are classified environmentally as category B projects is defined in Law 4014/2011.

At the moment the procedure of accepting new licenses for small wind turbines has been suspended until the associated ministerial decision is issued.

The IEC 61400-2 standard pertains to small wind turbines and classifies them as follows:

In addition, wind turbines are classified according to whether their axis of rotation is horizontal or perpendicular to the ground:

Horizontal axis wind turbines: They present bigger electrical energy yields in comparison with vertical axis wind turbines. However, in order to achieve that they require a constant stream and direction of wind. They have a yaw system which aligns them with the direction of the wind. Horizontal axis wind turbines have dominated the market of large-scale wind parks. Their disadvantage is that they don’t respond well to turbulent wind flow or to wind with variable characteristics.

Vertical axis wind turbines: They have smaller electrical energy yields in comparison with horizontal axis wind turbines. They respond better to alterations in the wind direction and they can rotate and produce power even under turbulent wind conditions. Therefore, they require no yaw mechanism. They are suitable for urban environments and they can compete with horizontal axis wind turbines in small scale applications. Their maintenance is easier to handle, since the generator and the gear box are usually installed on the ground.

Finally, wind turbines can be divided depending on whether they have a connection to the power grid or not:

Autonomous wind turbines are not connected to the utility grid and they are used to satisfy the electrical energy needs of a local consumer (e.g. countryside house). They demand a carefully dimensioned battery system so that a constant and uninterrupted power supply for the consumer can be ensured. Wind turbines which are connected to the grid can refer to an independent power producer or a self-consuming producer. The independent power producer produces exclusively for the distribution and sale of the energy to the utility grid whereas the self-consuming producer generates energy to satisfy his own needs and the remaining energy is fed to the grid.