elled ▁with ▁an ▁m ) ▁analysis , ▁for ▁example , ▁bud gets ▁for ▁the ▁amount ▁of ▁energy ▁of ▁one ▁kind ▁( ex er gy ) ▁that ▁is ▁required ▁to ▁make ▁or ▁transform ▁things ▁into ▁another ▁kind ▁of ▁product ▁or ▁service . ▁Emer gy ▁calculations ▁take ▁into ▁account ▁econom ics ▁which ▁can ▁alter ▁pure ▁physics - based ▁results . ▁Using ▁emer gy ▁life - cycle ▁analysis ▁research ers ▁have ▁concluded ▁that ▁materials ▁with ▁large ▁ref ining ▁costs ▁have ▁the ▁greatest ▁potential ▁for ▁high ▁rec ycle ▁benefits . ▁Moreover , ▁the ▁highest ▁emer gy ▁efficiency ▁acc ru es ▁from ▁systems ▁ge ared ▁toward ▁material ▁rec y cling , ▁where ▁materials ▁are ▁engine ered ▁to ▁rec ycle ▁back ▁into ▁their ▁original ▁form ▁and ▁purpose , ▁followed ▁by ▁adapt ive ▁reuse ▁systems ▁where ▁the ▁materials ▁are ▁rec yc led ▁into ▁a ▁different ▁kind ▁of ▁product , ▁and ▁then ▁by - product ▁reuse ▁systems ▁where ▁parts ▁of ▁the ▁products ▁are ▁used ▁to ▁make ▁an ▁entirely ▁different ▁product . ▁ ▁The ▁Energy ▁Information ▁Administration ▁( E IA ) ▁states ▁on ▁its ▁website ▁that ▁" a ▁paper ▁mill ▁uses ▁ 4 0 ▁percent ▁less ▁energy ▁to ▁make ▁paper ▁from ▁rec yc led ▁paper ▁than ▁it ▁does ▁to ▁make ▁paper ▁from ▁fresh ▁l umber ." ▁Some ▁critics ▁argue ▁that ▁it ▁takes ▁more ▁energy ▁to ▁produce ▁rec yc led ▁products ▁than ▁it ▁does ▁to ▁dispose ▁of ▁them ▁in ▁traditional ▁land fill ▁methods , ▁since ▁the ▁cur b side ▁collection ▁of ▁rec y cl ables ▁often ▁requires ▁a ▁second ▁waste ▁tr uck .