A 100-mile 230-kV transmission line under construction in northeast Colorado will connect the FPL Energy Peetz Table 400 MW wind turbines in Peetz, Colorado to the western grid at the Pawnee substation in Brush, Colorado. Two line segments make up this line: 78.2 miles being built by Hooper Corporation and a 21.5 mile segment being built by InfraSource Services under direction of general contractor Alliant Energy WindConnect.
The line consists of 795 ACSR bundled conductor on Sabre steel poles. The line is supported by approximately 1000 structures, 18 of which are engineered structures. Steel poles are used for the rest either direct embedded or direct embedment utilizing 48” culverts. The culvert is necessary to stabilize the ground in sandy soil so that the backfill can be compacted to hold the structure. Approximately 10 H-frame wood structures are utilized for existing transmission line crossings.
The terrain is very difficult to get into for line construction according to Mike McGuire, Project/Construction Manager, Alliant WindConnect, who says the line is being built largely across sand dunes. He said, “We are not allowed to use tracked equipment, so all construction equipment has to be on rubber tires. We use John Deere 4-wheel drive tractors to pull in all our equipment. As of the end of March, about 70 miles of line are framed and set. McGuire says conductor stringing began April 14th .
InfraSource is responsible for building 21 miles of line that leaves the ring bus east of the city of Peetz and leads to the wind field substation. Hooper Corp. is building the 78.2 miles of line that goes from Pawnee substation to the ring bus.
The project is scheduled for completion on July 15, 2007.