Transmission infrastructure cost estimating with a lack of clear project definition and conceptual design information is a difficult but necessary task as it relates to long-term planning activities. Due to the lack of readily available public information in infrastructure costs which factor in geographical, environmental and design basis variables some level of preliminary design must commonly be performed to achieve estimates which can inform long-term planning and associated decision making.
This report establishes an infrastructure cost estimating approach with assets which are commonly deployed in the transmission industry (overhead lines, substations, underground cable, submarine cable, HVDC and FACTS technologies). The approach includes establishing design basis factors along with adjustment factors which when utilized as adjustment inputs can tailor an estimate to a specific region and application. Along with the approach, costs are derived for key transmission assets which when combined can derive an estimated cost for a project or an overall suite of projects under consideration in a long-term planning effort. The report includes a companion estimating workbook which includes menu driven input selections and directions which allow a user to derive estimates for long-term planning functions. The report and accompanying estimate tool are tailored for estimating tasks which do not require the level of rigor necessary for definitive funding and/or project execution.