This text is machine translated.
About wind generators
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What was a wind generator?
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What was happening to the generated current?
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Important technical parameters
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Which wind generator for what?
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Practical advice
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Important notes on the installation and use of wind turbines
What was a wind generator?
A wind generator is a component of a wind turbine. The current is generated in this generator. For this purpose, the horizontal air movement is used to move the rotor blades of a propeller. At the axis of rotation is the actual generator, which converts the rotary movement into electrical current.
In order to always exploit the optimum air flow, these wind turbines are mounted on high-quality bearings and equipped with a wind vane, so that the wind always hits as parallel as possible to the rotation axis. This is comparable to a water-powered plant, so it is also called a wind turbine.
In order to use the wind without disturbing influences from buildings, trees or terrain, a wind wheel is mounted on a vertical mast or on roofs of buildings. Thus, maximum available wind can be converted into rotation of the actual wind generator, was Information on suitable and also to avoid installation locations can usually be found in the manufacturer's information, which is enclosed with the wind generator.
Other features of a wind generator are the number and size of the rotor blades. It is important to find the optimum between possible speed, technical effort and efficiency as well as the price. Logical minimum are two blades. Vertical wind generators are now also in use. These work independantly of the wind direction, however, they are awarded a lower efficiency.
In addition, there is a downstream electronics system that regulates the current storage and supply as well as the interaction with the consumers.
What was happening to the generated current?
As with a solar system, direct voltage (DC) is available at the generator output. Since the availability of electrical energy depends on meteorological conditions, converted energy must be temporarily stored. For this purpose, storage batteries are used from which the consumers are supplied in low-energy times. A charge controller takes over the management between charging and removing the energy.
As wind is not constant and predictable, wind turbines are sometimes used in combination with solar power systems. Thus, the energy source "nature" can be used in a hybrid and more effective way. Hybrid charge controllers are used to integrate the systems into the system to be supplied in order to ensure a safer supply. This ensures a higher yield from regenerative energy.
Hybrid wind-solar systems allow more cost-effective power generation than systems that use only one medium.
In most cases, it is possible to adjust the charge end voltage variably in hybrid charge controllers, so that memory batteries with different technologies can be used.
Important technical parameters
For private use, a small wind power plant or a wind generator is considered, which delivers a maximum power of 1.5 kilowatts (kW) at up to 48 volts. The specification of the rated power in kilowatts in the technical data of the wind turbine always refers to a defined wind speed.
For example, a wind wheel provides 600 watts (0.6 kW) of power at a wind speed of 10 meters per second (36 kilometers per hour). The output of electrical energy starts at a wind speed between 2 and 3 meters per second.
Due to the design, such wind turbines can be used up to a specified maximum wind speed. This results from the centrifugal force of the rotor blades, the stability of the assembly mast and the voltage rising with the speed at the output of the wind turbine.
Wind generators are usually safe up to wind strength 12, which was approximately 33 meters per second or 120 kilometers per hour, some even up to 50 meters per second (180 kilometers per hour). Electromagnetic and aerodynamic braking devices are installed as a safety plus, which limit an increase in the speed of the wind wheel to the maximum permissible level.
Some modern windmill models are equipped with WLAN interfaces, which enable the installation, control and control of the entire system via smartphone or PC and thus also comfortably from a distance.
Which wind generator for what?
In principle, any location that does not have a connection to the public power supply grid is eligible for the use of wind generators. Especially places where the installation of a mains connection would cause a disproportionate effort are predestined for wind generators.
With the use of hybrid systems that combine photovoltaic and wind energy, the application possibilities have increased considerably: Remote measuring stations, autonomous traffic control systems, combined with emergency call systems on highways and motorways, lighting solutions for billboards, holiday homes and charging stations for an electric car are thus feasible. Wind generators can also be used wherever mobile devices do not allow connection to the low-voltage network, for example, on boats or in caravans. In the garden, a small wind turbine can supply the required energy for the pond pump or the greenhouse lighting. Development aid projects in remote regions are not to be forgotten.
The use of a wind generator is ideal, whose output voltage correlates with the on-board voltage of the consumer, i.e. 12 or 24 V DC. If you want to use 230 Volt alternating current (AC), you should immediately rely on a system with integrated inverter.
Practical advice
Before purchasing a stationary wind wheel, check the prevailing regional wind conditions. It is recommended to measure wind over a period of at least three months at the intended location in order to assess whether a wind turbine is appropriate there. The preliminary measurement also shows the main wind direction from which the system should flow freely. The Deutsche Wetterdienst regularly publishes wind data for wind energy users, which are generated from numerous wind measurement sites throughout Germany. This allows you to estimate more precisely whether the price for the purchase of a wind generator is profitable.
Important notes on the installation and use of wind turbines
Familiarize yourself with the regulations in the state building regulations of your federal state before setting up wind turbines. In addition, other laws can apply, such as the Nature Conservation Act or the provisions of the Monument Protection Act. A large part of the German federal states permits the construction of wind turbines up to ten meters high without official approval.
A wind generator is exposed to high mechanical loads as the wind speed increases. This can be accompanied by a non-negligible noise load, which was to be taken into account when choosing the location.
There is a significant risk of injury from the rotating rotor. At high speeds, a rotor may appear transparent, so its visibility is limited. At the sharp edges of the rotor blades you can injure yourself at low speeds. Therefore, when maintenance is carried out, the rotor must be blocked mechanically or electrically by suitable means.
Each wind turbine should be grounded via the mast on the tower foundation. The cable cross-section from the generator to the charge controller should also be generously dimensioned.
Regularly check the rotor blades for notches, holes and dirt as well as for correct seating and completeness of the fastening screws. Irregularities cause unbalances that endanger not only the generator but also the mast. It is recommended to replace the blades after approximately five years of operation.