▁make ▁a ▁significant ▁reduction ▁in ▁tur bine ▁output , ▁with ▁wind ▁direction ▁variations ▁of ▁ ± 3 0 ° ▁being ▁quite ▁common ▁and ▁long ▁response ▁times ▁of ▁the ▁tur b ines ▁to ▁changes ▁in ▁wind ▁direction . ▁At ▁high ▁wind ▁spe eds , ▁the ▁wind ▁direction ▁is ▁less ▁variable . ▁ ▁Elect rical ▁bra king ▁▁ ▁B rak ing ▁of ▁a ▁small ▁wind ▁tur bine ▁can ▁be ▁done ▁by ▁dump ing ▁energy ▁from ▁the ▁generator ▁into ▁a ▁res istor ▁bank , ▁converting ▁the ▁kin etic ▁energy ▁of ▁the ▁tur bine ▁rotation ▁into ▁heat . ▁This ▁method ▁is ▁useful ▁if ▁the ▁kin etic ▁load ▁on ▁the ▁generator ▁is ▁suddenly ▁reduced ▁or ▁is ▁too ▁small ▁to ▁keep ▁the ▁tur bine ▁speed ▁within ▁its ▁allowed ▁limit . ▁ ▁Cy clic ally ▁bra king ▁causes ▁the ▁bl ades ▁to ▁slow ▁down , ▁which ▁increases ▁the ▁st alling ▁effect , ▁reducing ▁the ▁efficiency ▁of ▁the ▁bl ades . ▁This ▁way , ▁the ▁tur bine ' s ▁rotation ▁can ▁be ▁kept ▁at ▁a ▁safe ▁speed ▁in ▁faster ▁wind s ▁while ▁maintain ing ▁( nom inal ) ▁power ▁output . ▁This ▁method ▁is ▁usually ▁not ▁applied ▁on ▁large ▁grid - connected ▁wind ▁tur b ines . ▁ ▁Mechan ical ▁bra king ▁ ▁A ▁mechanical ▁drum ▁bra ke ▁or ▁disk ▁bra ke ▁is ▁used ▁to ▁stop ▁tur bine ▁in ▁emer gency ▁situation ▁ ▁such ▁as ▁extreme ▁g ust ▁events ▁or ▁over ▁speed . ▁This ▁bra ke ▁is ▁a ▁secondary ▁means ▁to ▁hold ▁the ▁tur bine ▁at ▁rest ▁for ▁maintenance , ▁with