. ▁The ▁aer ost ats ▁are ▁usually , ▁but ▁not ▁always , ▁sh aped ▁to ▁achieve ▁a ▁k iting ▁lif ting ▁effect . ▁Re charg ing ▁le aked ▁lif ting ▁gas ▁receives ▁various ▁solutions . ▁In ▁case ▁of ▁product ive ▁wind s ▁the ▁aer ost ats ▁are ▁typically ▁blow n ▁down ▁by ▁the ▁aer od ynamic ▁drag ▁applied ▁on ▁the ▁wide ▁and ▁un av oid able ▁Reyn olds ▁surface ▁ex cluding ▁them ▁de ▁fact o ▁from ▁the ▁H A WP ▁category . ▁▁ ▁W . ▁R . ▁Ben oit ▁US ▁Pat ent ▁ 4 3 5 0 8 9 7 ▁L ighter ▁than ▁air ▁wind ▁energy ▁conversion ▁system ▁by ▁William ▁R . ▁Ben oit , ▁file d ▁Oct ▁ 2 4 , 1 9 8 0 , ▁and ▁issued : ▁Sep ▁ 2 1 , ▁ 1 9 8 2 . ▁▁ ▁The ▁T W IND ▁system ▁( ▁International ▁pat ent ▁application ▁P CT / W 0 2 0 1 0 / 0 1 5 7 2 0 ) ▁is ▁based ▁on ▁the ▁use ▁of ▁a ▁sail ▁surface ▁elev ated ▁by ▁the ▁clim bing ▁force ▁of ▁an ▁aer ost atic ▁bal lo on ▁connected ▁to ▁the ▁ground ▁by ▁a ▁cable ▁used ▁also ▁for ▁energy ▁transmission . ▁The ▁wind ▁present ▁at ▁high ▁alt itudes ▁creates ▁a ▁horizontal ▁push ▁on ▁the ▁sail ▁which ▁in ▁its ▁movement ▁transm its ▁this ▁energy ▁to ▁the ▁ground ▁via ▁the ▁connecting ▁cable . ▁At ▁the ▁end ▁of ▁its ▁movement ▁forward , ▁the ▁sail ▁surface ▁is ▁reduced ▁allowing ▁it ▁to ▁move