Fig. 3From: District cooling network optimization with redundancy constraints in SingaporeSankey diagram of Eq. (8). Ingoing cooling power flow \(\pi _{ijt}^{\text {in}}\) from vertex v i is reduced by variable losses (1−x ij ), fixed losses and cooling demand (y ijt ) before leaving to vertex v j as power flow \(\pi _{ijt}^{\text {out}}\) Back to article page