In the search for new locations, the German wind energy

industry is increasingly targeting the woods. For example, in

early December of this year, near the Bavarian town of Hof

a forest wind farm with five 2 MW turbines went in operation.

Together, they are expected to produce about 22.5 million

kilowatt hours of electricity every year, enough to supply about

7,500 households.

The wind turbines at this site have a rotor diameter of 82 m and

a hub height of 138 m. The large hub is an important technical

requirement in order to take advantage of the wind over

forests. “The German forest has mainly a tree height between

15 and 20 meters, says Peter Herbert Meier of the German

technical service corporation T V Süd Industrie Service. “Just

above the treetops is a 15 to 40 meter wide air zone, where

there is considerable turbulence and relatively low wind

speeds. Above this zone, the influence of trees is lower and the

wind speed increases.” High hubs combined with large rotor

diameters make it possible to generate profits over the forests

of the inland, which until a few years ago were only feasible in

coastal and exposed mountain regions.

Forest sites also have some other advantages on their

side. “The ‘reduced visibility’ of the wind turbines by the

surrounding forest increase their general acceptance,” says

Michael Lüer of Juwi Wind GmbH. His company is part of the

German Juwi Group, one of the wordwide leading companies in

the area of renewable energies. “And because of the distances

to the housing areas, there are only relatively few conflicts

caused by sound and shadow.”

Also for the forestry, there are advantages. Thus, the resulting

open space around the wind turbines can be used as forest

meadows, wood storage and grazing areas for the game.

To minimize changes in the ecosystem of the forest, according

Lüer a number of points must be considered. The clearings can

be kept small, if the sites are carefully planned together with the

Forest Authorities. In addition, as compensation for the cleared

forest comparable areas are reforested again. For access to the

sites in most cases the existing forest roads can be used, so

that no further intervention is necessary. In the designation, low-

value, monoculture locations within large, contiguous forests

areas are to be preferred. The edges of the forests should be

avoided.

According to the German Federal Wind Energy Association, the

experiences gained with the use of wind energy in the German

forests have shown that wind turbines have no negative impact

on the surrounding forest and the forest fauna. Disturbances

resulting from transport and construction will take place only in

the building phase, interference with service and maintenance

doesn’t differ much from the frequency of standard forest work.

According to the Wind Energy Association, even for bats, wind

turbines in forest areas are no problem. Most species of bats fly

so low that they do not stumble into the radius of the swept rotor

area.

In the search for new locations, the German wind energy industry is increasingly targeting the woods. For example, in early December 2010, near the Bavarian town of Hof a forest a wind farm with five 2 MW turbines went in operation. Together, the turbines are expected to produce about 22.5 million kilowatt hours of electricity every year; enough to supply about 7,500 households. The wind turbines at this site have a rotor diameter of 82 meters and a hub height of 138 m. The large hub is an important technical requirement in order to take advantage of the wind over forests.

“The German forest has mainly a tree height between 15 and 20 meters, says Peter Herbert Meier of the German technical service corporation TV Süd Industrie Service. “Just above the treetops is a 15 to 40 meter wide air zone, where there is considerable turbulence and relatively low windspeeds. Above this zone, the influence of trees is lower and the wind speed increases.” High hubs combined with large rotor diameters make it possible to generate profits over the forests of the inland, which until a few years ago were only feasible in coastal and exposed mountain regions. Forest sites also have some other advantages on theirside.

“The ‘reduced visibility’ of the wind turbines by the surrounding forest increase their general acceptance,” says Michael Lüer of Juwi Wind GmbH. His company is part of the German Juwi Group, one of the wordwide leading companies in the area of renewable energy. “And because of the distances to the housing areas, there are only relatively few conflicts caused by sound and shadow.” Also for the forestry, there are advantages.

Thus, the resulting open space around the wind turbines can be used as meadows, wood storage and grazing areas for the game. To minimize changes in the ecosystem of the forest, according to Lüer, a number of points must be considered. The clearings can be kept small, if the sites are carefully planned together with the Forest Authorities. In addition, as compensation for the cleared forest comparable areas are reforested again. For access to the sites in most cases the existing forest roads can be used, so that no further intervention is necessary.

In the designation, low-value, monoculture locations within large, contiguous forests areas are to be preferred. The edges of the forests should be avoided. According to the German Federal Wind Energy Association, the experiences gained with the use of wind energy in the German forests have shown that wind turbines have no negative impact on the surrounding forest and the forest fauna. Disturbances resulting from transport and construction will take place only in the building phase, interference with service and maintenance doesn’t differ much from the frequency of standard forest work. According to the Wind Energy Association, even for bats, windturbines in forest areas are no problem. Most species of bats fly so low that they do not stumble into the radius of the swept rotor area.