“…x p,ggf = f u,ggfḢpeak,ggf , y p,ggf = C a,p,ggf (25) x e,ggf = f u,ggfḢa,ggf , y e,ggf = C a,e,ggf (26) C pv,ggf = c pv,ggf y p,ggf + y e,ggf (27) The energy trading is modelled considering the current spot market price c eex in (28) and (29) as well as the energy related trading fees c trad,eex in (30). Because trading of gas is based on the higher heating value [31] a conversion factor f u,eex is used to convert from lower to higher heating value in (28)- (30).…”