1 5 . ▁ ▁Once ▁again ▁supplied ▁by ▁Bab cock ▁& ▁Wil co x , ▁it ▁was ▁installed ▁beside ▁bo iler ▁ 1 2 . ▁In ▁order ▁to ▁accomplish ▁this , ▁the ▁existing ▁fac ade ▁had ▁to ▁be ▁demol ished , ▁the ▁new ▁area ▁c ement ed , ▁and ▁the ▁met all ic ▁structure ▁covered ▁in ▁brick ▁built , ▁always ▁with ▁the ▁same ▁technique ▁and ▁look . ▁Const ruction ▁work ▁began ▁at ▁the ▁beginning ▁of ▁ 1 9 5 0 ▁and ▁the ▁bo iler ▁began ▁operating ▁when ▁construction ▁was ▁concluded ▁in ▁mid - 1 9 5 1 , ▁a ▁time ▁when ▁the ▁power ▁station ▁was ▁already ▁acting ▁as ▁a ▁reserve . ▁ ▁The ▁almost ▁ten - year ▁difference ▁between ▁the ▁installation ▁of ▁the ▁first ▁high ▁pressure ▁bo ilers ▁and ▁this ▁final ▁one ▁results ▁in ▁differences ▁between ▁them . ▁For ▁instance , ▁bo iler ▁ 1 5 ▁already ▁came ▁equ ipped ▁with ▁nap h tha ▁inject ors ▁( in ▁the ▁others , ▁these ▁were ▁added ▁progress ively ), ▁the ▁convey or ▁bel t ▁is ▁lower , ▁the ▁control ▁table ▁is ▁more ▁advanced ▁in ▁register ing ▁and ▁reading ▁the ▁bo iler ' s ▁oper ational ▁data , ▁the ▁bo iler ▁dust ▁( ash ) ▁pan ▁has ▁six ▁coal ▁ho ppers ▁to ▁exp el ▁bo iler ▁dust ▁and ▁coal ▁( in ▁the ▁other ▁there ▁were ▁only ▁three ), ▁and ▁it ▁is ▁also ▁slightly ▁larger ▁in ▁size . ▁ ▁Integr ation ▁into ▁the ▁National ▁Electric ▁Grid ▁ ▁The ▁National ▁Elect r ification ▁Law ▁made ▁producing ▁hydro elect