ERCOT is in the early stages of evaluating what transmission will be needed to accommodate the massive amount of wind generation that is projected to come online in the Texas Panhandle, a region that currently has no native load.
Nearly half of the wind interconnection requests in ERCOT are in the Panhandle, or 11 GW out of the total 21 GW in ERCOT.
Of that 11 GW, nearly 3.5 GW have signed interconnection agreements, comprising 11 projects that represent 273 miles of line, according to a presentation ERCOT made to the Regional Planning Group (RPG) on Aug. 27. Those projects are scheduled to enter service in the 2013-2016 period.
As a result of the CREZ buildout, the Panhandle is able to handle 2.5 GW of generation, Jeff Billo, manager of transmission planning for ERCOT, told TransmissionHub on Sept. 30.
The Panhandle Import Study that ERCOT is conducting is a continuation of what it began in the CREZ study, Billo said.
“Initially, when we did the CREZ study, we decided that really we needed to not complete the [Panhandle] studies until we had a better idea of what generation was going to show up,” Billo said. “We’re trying to complete the studies we started on initially with the CREZ, and then look at, as we meet or exceed those levels [of generation], what will be the next transmission improvements that are needed?”
ERCOT is evaluating what the transmission needs would be under two scenarios: accommodating an additional 2.5 GW of wind generation, for a total of 5 GW, or accommodating an additional 5 GW of wind generation, for a total of 7.5 GW.
Billo cautioned that those figures are preliminary.
“I wouldn’t put too much stock into those being the final upgrades at this point,” he said, adding that the information ERCOT shared with the RPG in August was designed to solicit feedback from stakeholders and interested parties.
A spokesperson for ERCOT said the study won’t be completed until the end of the year.
According to the presentation, the upgrades or new projects that would be needed to accommodate the 5 GW scenario would be either within the Panhandle or West Texas. Under the 7.5 GW scenario, however, projects may be needed outside of West Texas.
“What studies are showing is, [as you get] closer to 7.5 GW scenario, the problems you see on the system aren’t limited to the Panhandle; it starts to become more of a stability constraint between all of West Texas, including the Panhandle, and the rest of ERCOT,” Billo said. “When you get to the higher level scenario it may not just be upgrades for the Panhandle; upgrades to other parts of the ERCOT system may be needed.”
According to the preliminary study, in order to accommodate 5 GW of wind generation, the Panhandle would need to upgrade three 345-kV lines from single- to double-circuit lines and build a new 200-mile, 345-kV line from Ogallala to Long Draw. The three upgrades would include the 27-mile Windmill to Ogallala, 93-mile Windmill to Alibates and 47-mile Ogallala to Tule Canyon transmission lines.
In order to accommodate 7.5 GW of generation, those projects would be needed in addition to two to three new transmission lines, depending on two options. The first option would call for the 5 GW scenario projects and a 175-mile, 345-kV Gray to Riley line and a 175-mile, 345-kV Windmill to Edith Clarke line.
The second option would require the 5 GW scenario projects, the Gray to Riley line, and a 130-mile, 345-kV line from Windmill to Cottonwood and a 150-mile, 345-kV line from Cottonwood to West Shackelford.
All of the new builds, which would be double-circuit lines, would require new right-of-way, Billo said.
ERCOT is also conducting the Houston Import Study to determine what, if any, new transmission is needed to accommodate import capacity to support Houston’s growing demand. Three companies, including Lone Star Transmission, CenterPoint Energy (NYSE:CNP) and Cross Texas Transmission in partnership with Garland Power & Light, have proposed projects to increase import capacity into Houston.