The economic analysis of 115/22 kV substation with transformer rated 10-25 MVA and peak demand between 4-9
MW indicated that the ROI of AIS and GIS in case of not
considering outage cost is 3.41-10.70 years and 4.92-14.61 years, respectively. The ROI of AIS and GIS in case of considering outage cost is 2.21-6.79 years and 3.18-9.23 years, respectively. The economic assessment for construction
115/22 kV substation with peak demand 4-9 MW in term of
ROI is displayed in Fig. 3