▁energy ▁values ▁to ▁be ▁finite , ▁al beit ▁negative . ▁ ▁The ▁singular ity ▁at ▁ ▁in ▁the ▁formula ▁for ▁gravit ational ▁potential ▁energy ▁means ▁that ▁the ▁only ▁other ▁apparently ▁reasonable ▁alternative ▁choice ▁of ▁convention , ▁with ▁ ▁for ▁, ▁would ▁result ▁in ▁potential ▁energy ▁being ▁positive , ▁but ▁infinitely ▁large ▁for ▁all ▁non zero ▁values ▁of ▁r , ▁and ▁would ▁make ▁calculations ▁involving ▁sums ▁or ▁differences ▁of ▁potential ▁energ ies ▁beyond ▁what ▁is ▁possible ▁with ▁the ▁real ▁number ▁system . ▁Since ▁phys ic ists ▁ab hor ▁infin ities ▁in ▁their ▁calculations , ▁and ▁r ▁is ▁always ▁non - zero ▁in ▁practice , ▁the ▁choice ▁of ▁ ▁at ▁infinity ▁is ▁by ▁far ▁the ▁more ▁prefer able ▁choice , ▁even ▁if ▁the ▁idea ▁of ▁negative ▁energy ▁in ▁a ▁gravity ▁well ▁appears ▁to ▁be ▁peculiar ▁at ▁first . ▁ ▁The ▁negative ▁value ▁for ▁gravit ational ▁energy ▁also ▁has ▁deeper ▁imp lications ▁that ▁make ▁it ▁seem ▁more ▁reasonable ▁in ▁cosm ological ▁calculations ▁where ▁the ▁total ▁energy ▁of ▁the ▁universe ▁can ▁meaning fully ▁be ▁considered ; ▁see ▁infl ation ▁theory ▁for ▁more ▁on ▁this . ▁ ▁Us es ▁ ▁Gra v it ational ▁potential ▁energy ▁has ▁a ▁number ▁of ▁practical ▁uses , ▁not ably ▁the ▁generation ▁of ▁p ump ed - storage ▁hydro elect ric ity . ▁For ▁example , ▁in ▁Din or wig , ▁Wales , ▁there ▁are ▁two ▁la kes , ▁one ▁at ▁a ▁higher ▁elev ation ▁than ▁the ▁other . ▁At ▁times ▁when ▁sur plus ▁electric ity ▁is ▁not ▁required ▁( and ▁so ▁is