2 0 0 5 . ▁ ▁S TE P ▁▁ ▁S TE P ▁stands ▁for ▁S ust ain able ▁Transport ▁Energy ▁for ▁Per th . ▁This ▁initi ative ▁of ▁the ▁Government ▁of ▁Western ▁Australia ' s ▁Department ▁for ▁Pl anning ▁and ▁In frastr ucture ▁( D PI ), ▁was ▁the ▁responsibility ▁of ▁the ▁public ▁transport ▁organisation ▁Trans per th , ▁though ▁it ▁was ▁run ▁by ▁contract ed ▁operator ▁Path ▁Trans it . ▁They ▁were ▁operated ▁in ▁the ▁city ▁Per th , ▁the ▁capital ▁of ▁Western ▁Australia . ▁These ▁three ▁bus es ▁are ▁called ▁" E co B uses ". ▁The ▁project ▁ran ▁from ▁ 2 0 0 1 - 2 0 0 5 , ▁with ▁the ▁first ▁bus es ▁in ▁service ▁in ▁September ▁ 2 0 0 4 . ▁ ▁The ▁Per th ▁trial ▁received ▁A $ 2 . 5 ▁million ▁fund ing ▁from ▁the ▁Department ▁of ▁the ▁Environment ▁and ▁Heritage ▁and ▁the ▁Australian ▁Green house ▁Office . ▁It ▁was ▁end ors ed ▁by ▁the ▁United ▁Nations ▁Environment ▁Program me ▁and ▁the ▁United ▁Nations ▁Indust rial ▁Development ▁Organ ization . ▁ ▁B P ▁produced ▁the ▁hydro gen ▁as ▁a ▁by - product ▁at ▁its ▁K win ana ▁oil ▁ref in ery ▁( ▁south ▁of ▁Per th ). ▁The ▁hydro gen ▁was ▁then ▁transport ed ▁by ▁road ▁in ▁spe cially ▁designed ▁road ▁tank ers ▁to ▁a ▁bus ▁dep ot ▁in ▁the ▁northern ▁sub ur bs ▁of ▁Per th . ▁Per th ' s ▁bus es ▁achieved ▁greater ▁reli ability ▁and ▁better ▁fuel ▁economy ▁than