The Public Utility Commission (PUC) of Texas, in a Jan. 15 order, approved CenterPoint Energy Houston Electric’s application to build a new 345-kV double-circuit transmission line in Grimes, Harris and Waller counties in Texas.
CenterPoint will use route 1A-Modified, which is about 58.7 miles long and comprised of links B, F, LA, I3, LD, N1A, K3, N1C, H2, V2A, L3, A3, C3, D3A, M3, O3, P3, Q3 and R3.
As noted in the order, CenterPoint last April filed its application to amend its certificate of convenience and necessity (CCN) for a Zenith-to-Gibbons Creek 345-kV double-circuit transmission line in Grimes, Harris and Waller counties. Also last April, but in a separate application, Cross Texas Transmission sought to amend its CCN for a Limestone-to-Gibbons Creek 345-kV double-circuit transmission line in Brazos, Freestone, Grimes, Leon, Limestone, Madison and Robertson counties in Texas, the PUC added.
Together, the CenterPoint and Cross Texas transmission lines, along with other substation and transmission line upgrades, constitute the Houston Import Project (HIP), which ERCOT has deemed as critical to the reliability of the ERCOT system.
By agreement of the parties, the PUC added, both dockets (Docket Nos. 44649 and 44547) were consolidated for hearing.
As TransmissionHub reported, the PUC, in a Jan. 13 final order, approved Cross Texas’ application to build a new 345-kV double-circuit transmission line in Brazos, Freestone, Grimes, Leon, Limestone, Madison and Robertson counties.
As noted in the PUC’s Jan. 15 order, the HIP consists of these six components: construction of a new 345-kV line terminating into the Limestone and Gibbons Creek substations; construction of a new 345-kV line terminating into the Gibbons Creek and Zenith substations; upgrades to the existing Limestone substation; upgrades to the existing Gibbons Creek substation; upgrades to the existing Zenith substation; and the upgrade of the existing T.H. Wharton-to-Addicks 345-kV line. The stated purpose of the HIP is to increase the transmission import capacity serving the Houston area from the northern regions of the ERCOT system, the PUC said.
The PUC said that the State Office of Aministrative Hearings’ (SOAH) administrative law judges (ALJs) last October recommended that the PUC grant CenterPoint’s application and adopt filed route 1A, but with monopoles along the entire length of the route instead of the planned lattice towers, the PUC said, noting that the ALJs last November filed recommended changes to the proposal for decision in response to parties’ exceptions and replies.
The PUC said that it mostly agrees with the ALJs’ recommendations and adopts the proposal for decision issued, with some modifications. Regarding routing, the PUC said that it finds that link I3 should be used instead of links LB and LC and that link K3 should be used instead of link N1B. The use of link I3 instead of links LB and LC would lessen the route’s cost by about $10m, which would shorten the distance, and is more favorable environmentally, the PUC said.
While the use of link K3 is more costly than link N1B, link K3 parallels more existing transmission line and has fewer turns. The PUC also said that the substitution of links I3 and K3 on filed route 1A creates a new route, which is designated in the order as route 1A-Modified.
The PUC also said that it rejects the ALJs’ recommendation to use monopoles along the entire length of route 1A and instead decides to use monopoles along only certain parts of route 1A-Modified. The PUC said that monopoles are to be used on the route approved by the PUC in these locations specifically to mitigate the impact on many landowners, who are already burdened with an existing 345-kV transmission line:
- All of link K3
- Link N1C, between structure numbers 973 and 986 (inclusive)
- Link LA, from the crossing of U.S. 290 to structure number 224 (inclusive) and between structure numbers 368 and 380 (inclusive)
- All of link I3
- Link N1A between structure numbers 829 and 843 (inclusive)
CenterPoint is to further use monopoles, for instance, anywhere a directly affected landowner requests monopoles and is willing to bear the difference in actual costs between lattice towers and monopoles.
The estimated total cost to build route 1A-Modified, including substation costs, relocation costs, and lattice towers, is about $269.7m. If monopoles are used along the entire route, the cost would be about $307.6m, the PUC added. The estimated cost of route lA-Modified, as approved with monopoles along only certain parts, will be significantly less than about $307.6m, the PUC said, adding “The estimated cost of the proposed transmission line and substation facilities is reasonable when compared to the estimated cost of construction of the other proposed alternative routes for this project.”
Discussing the analysis of need for the HIP, the PUC noted that CenterPoint conducted a contingency analysis using a February 2013 ERCOT steady state working group planning base cases. CenterPoint’s contingency analysis revealed several 345-kV circuits entering the Houston area from the north and northwest that would likely be overloaded beginning in 2018, and would therefore not satisfy the ERCOT Planning Guide, the PUC said.
The CenterPoint contingency analysis found that the overloads on the north-to-Houston interface beginning in 2018 could constitute violations of NERC reliability standards if not otherwise addressed, and could result in fines being levied on CenterPoint, the PUC said.
On July 25, 2013, CenterPoint identified a reliability need for an additional transmission line into the Houston region by 2018 and reported the findings of its evaluation in the CenterPoint Energy Houston region import capacity project, the PUC said.
The PUC further noted that based on an ERCOT independent review, ERCOT concluded that additional transmission capacity is needed to reliably serve the Houston area under the 2018 summer peak condition. Based upon the ERCOT independent review, the PUC added, ERCOT concluded that the HIP is the best solution to meet the need for additional import capacity.
The PUC said that the HIP will facilitate robust wholesale competition by increasing the transfer capacity between the northern and coastal regions, thereby reducing constraints and allowing potentially more efficient generation in each zone to compete in the other.
A new import path into the Houston area will open the market for new, more efficient generation sources to be constructed outside of that area and sell power into Houston, which will introduce additional competition for the legacy generation resources in the area, the PUC said.
Route 1A-Modified mitigates many of the specific concerns expressed by the community at public meetings, the PUC said.
The use of monopole structures on certain parts of the route will mitigate the line’s impact by reducing the amount of ROW; lessen the aesthetic impact; conform to the use of monopoles in compressed construction sites; and conform to the use of monopoles in the Cross Texas project, the PUC said.
The proposed line will not significantly impact the use or enjoyment of parks and recreational areas, and no adverse effects to archaeological or historical resources are anticipated as a result of project construction, the PUC said.
Additionally, the line will have no significant impact, if any, on aquatic/hydric habitat, it will have no significant impact on local wildlife, and no significant impacts to federal- or state-listed threatened or endangered species are anticipated.
Among other things, the PUC said that if CenterPoint or any of its respective contractors encounter any artifacts or other cultural resources during project construction, work is to cease immediately in the vicinity of the resource, and the discovery is to be reported to the Texas Historical Commission.
Also, CenterPoint is to update the reporting of the project on its monthly construction progress report prior to the start of construction to reflect the final estimated cost and schedule, the PUC said.