Wind Energy
___________________________________________________________________________________________________________________________________________Wind energy refers to that technology that takes advantage of the kinetic energy of the wind to convert it into electrical or mechanical energy.
The applications are multiple: from small power installations for water pumping or rural electrification of isolated cores (by machinery of a few kW of nominal power) to wind farms, with wind turbines of nominal power MW , which connect to the power grid.
The realization of wind farms requires locations where the characteristics of the wind meet a series of conditions in terms of speed, continuity and stability. Normally, average annual wind speeds greater than 6m / s are necessary. The distribution and arrangement of wind turbines in a wind farm depends on the orography of the land and the predominant wind direction of the area.
Normally wind turbines are positioned linearly, following the profile of the crest line and oriented according to wind conditions. The distance between wind turbines, although it is a function of the wind direction, is maintained between 1.5 and 3 times the diameter of the blades.
Facilities
Isolated installations (not connected to the electricity grid): Water pumping, electricity supply to homes and other consumption centers. In water pumping installations it is usual to use multi-blade aero pumps. From the wind the mechanics that drives the pump of the installation that will allow the water to rise to the tank is generated. These aerobombas work at low speed and for this you must count the maximum number of blades possible, usually between 12 and 24. The use of wind turbines for water pumping is common in rural areas and for own consumption.
Thus two types of installations can be distinguished:
Installations connected to the electricity grid: Usually in the form of wind farms. A wind farm is a set of wind turbines connected to each other at low voltage which, by the action of the wind, converts the kinetic energy into electrical energy that, after being transformed into high voltage, will be connected to the electricity grid.
Wind energy also allows the supply of electrical energy to homes and other centers of consumption isolated from the electricity grid. For this type of installation, small power wind turbines and a very reliable technology are used that demand very basic maintenance . Normally, these installations are usually hybrid, wind, photovoltaic solar, since they take advantage of the two resources, the wind and the sun.
Thus two types of installations can be distinguished:
Installations connected to the electricity grid: Usually in the form of wind farms. A wind farm is a set of wind turbines connected to each other at low voltage which, by the action of the wind, converts the kinetic energy into electrical energy that, after being transformed into high voltage, will be connected to the electricity grid.
Wind energy also allows the supply of electrical energy to homes and other centers of consumption isolated from the electricity grid. For this type of installation, small power wind turbines and a very reliable technology are used that demand very basic maintenance . Normally, these installations are usually hybrid, wind, photovoltaic solar, since they take advantage of the two resources, the wind and the sun.
Wind Turbines
There is a wide range of wind turbines:Horizontal axis machines: with an axis of rotation that is parallel to the ground.
Three-wheel wind turbines: with unit powers that can range between 600 kW and up to more than 2,000 kW. This typology is the one that presents the best operating characteristics and best performance. multi-blade wind turbines: 12 to 24 blades on the rotor, which allow to take advantage of lower speed winds. They are often used for water pumping.
Vertical axis machines: In this case, the axis of rotation is perpendicular to the ground. Its use is the least common.
Components
The components of the wind turbines are the following:The rotor: It is the part of the machine that transforms wind energy into mechanical energy. Increasing the diameter of the blades can increase the surface area of wind and the power provided by the machine. The power supplied by the wind per unit of swept area is known as wind power density.
Above a power density of 200 W / m2 it can already be profitable to generate electricity from wind turbines.
The multiplier: It is a set of gears that transform the low speed at which the rotor shaft rotates (between 20 and 30 turns per minute) at a higher speed, which is communicated to the axis that makes turn the generator.
The generator: The goal of the generator is to transform the mechanical energy from the machine's rotor into electrical energy. This energy will be discharged into the electricity grid or used by a consumption center attached to the installation.
The gondola: It is the frame and casing assembly of the wind turbine.
The frame: It is the part on which the main mechanical elements (the rotor, the multiplier, the generator) of the wind turbine are coupled and is located on the tower. This frame is protected by a housing, usually made of fiberglass and polyester, reinforced with stainless steel profiles.
The blades: They are the elements of the wind turbine responsible for capturing the kinetic energy of the wind. It is one of the most critical components of the machine, since in blades of great length, which allow a better use of energy, the high speeds that reach the extremes take to the limit the resistance of the materials with which they are manufactured (usually fiberglass and polyester).
