FAQ
1. When is a site suitable for a wind turbine?
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Ideally, wind turbines require a free, undisturbed flow of wind for optimal energy generation. Obstacles, for example in the form of buildings or trees, change the wind direction and speed and lead to turbulence. These have a negative impact on energy production and the service life of the system.
For an optimal free and undisturbed incoming flow, the wind turbines should be located outside of the slipstream of obstacles and the resulting turbulence areas. If an obstacle exceeds the height of the turbine to be erected, a horizontal distance of at least 20 times the height of the obstacle should be maintained. For example, if the obstacle is a 5 m high building, then the system should be 100 m away from this building.
In general, the higher the tower, the higher the power generation because wind speed increases with height and turbulence decreases. Depending on the distance to the obstacle, the small wind turbine should be up to 2 times higher than the obstacle. We recommend mast heights of at least 10m.
2. Can I mount a small wind turbine on the roof?
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In principle, it is possible to mount a small wind turbine on the roof, but there are extensive disadvantages that must be pointed out here. Static problems can be problematic if the roof construction cannot withstand the loads of the wind turbine. Furthermore, the transmission of structure-borne noise and vibrations into the building can cause noise pollution, which residents find unpleasant. After all, the roof is wind-technically a rather unfavorable location since the wind is deflected here and turbulence occur, which reduces the yield of the system. Against this background, it is advisable to set up a wind turbine on a ground-mounted mast. However, should a roof construction be considered, it requires particularly careful planning by experts.
3. Which wind conditions make the use of a small wind turbine useful?
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Normally, the average annual wind speed for a small wind turbine to operate economically should be at least 4m/s to 5 m/s at hub height. In relation to the main wind direction, there should be no obstacles in front of the small wind turbine.
4. How do I determine the wind conditions at my location?
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The most reliable statement about the wind conditions at a location is provided by a wind measurement, which should be carried out at the location over a period of at least 3 months, at best 1 year.
Information on the wind situation at a location can also be found on weather maps, for example in Germany from the German Weather Service (www.dwd.de), here in particular the maps with the mean annual speeds at a height of 10m, in UK on the homepage of the Met Office (www.metoffice.gov.uk), a meteorological service company or in the global wind atlas (www.globalwindatlas.info) .
Since small wind turbines are often confronted with turbulent wind conditions near the ground, these sources provide only rough information on local sites.
5. What are the application areas of small wind turbines?
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Small wind turbines can be used in grid-parallel and in minigrid operation. In grid parallel operation, the WindStream5 is connected to the public power grid, which means that the energy generated can be used by the user or fed into the grid. A minigrid is an independent electricity distribution network without connection to the public grid.
6. How economical is a small wind turbine?
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The profitability of a small wind turbine depends on a variety of factors. These include the wind conditions at the site, the investment and financing costs of the system or the operating and maintenance costs. First indications of profitability can also be determined, for example, with an online calculator (e.g. at www.klein-windanlagen.de ).