Lubbock Power & Light (LP&L), the third-largest municipal utility in Texas, received preliminary approval for its plan to construct the first half of a new 230-kV line that will connect three of LP&L’s four tie substations through which the utility purchases power from Xcel Energy (NYSE:XEL) via the Southwest Power Pool (SPP).
The LP&L staff plan received unanimous approval from the Lubbock Electric Utility Board Sept. 18.
“What we’re doing is moving from a radial to a loop system,” an LP&L spokesperson told TransmissionHub Sept. 19, noting that the change will enhance the reliability of the system.
“We move [purchased power] through those four tie substations that we’re going to loop together,” the spokesperson said. “If we lose one of those ties, then we have to do some switching to be able to move the power around what we’ve lost. Right now, if we had a loop, that would alleviate some of that problem,” the spokesperson said.
LP&L’s system, which serves 100,000 meters in a city of 234,000 people, currently depends on substations acting independently to transfer power from the transmission side to the distribution side.
Some of LP&L’s operational challenges stem from the 2010 purchase of Lubbock’s distribution assets from Xcel Energy. That transaction left LP&L with voltages ranging from 4-kV to 69-kV over two separate systems.
“We have our distribution system, plus we have the Xcel distribution system that we own, with multiple distribution voltages, further complicating that switching process, so that’s one of the reasons we’re moving toward a 230-kV loop.” the spokesperson said.
In addition to enhancing system reliability, a loop system will make it easier for the utility to add generation.
“In the future, if we decide not to buy any more power from an outside source such as the new SPP [integrated marketplace, set to debut in March 2014] and decide to build our own generation, that [loop] will help us distribute that power in Lubbock as well,” the spokesperson said.
The plan next goes to the City Council, which must approve funding for the project before it can move forward. A final decision from the City Council is expected by November.
“We will likely issue a design-build contract, probably in the early spring, because we’d like to build this in about a year or so,” the spokesperson said.
The second half of the project, which would tie in the fourth substation, will be built later in the decade, the spokesperson said.
When completed, the project will add 15 miles of 230-kV line at a cost currently estimated at $26m.
“Right now, we’re anticipating this could be a benefit to us for a 20 or 30-year period,” the spokesperson said.