CenterPoint Energy proposes to construct a new 345 kilovolt (“kV”) single-circuit transmission line on double-circuit capable structures located in Wharton County, Texas, that would connect EDF Renewables Development Inc.’s planned Space City Solar Interconnection Substation to the existing CenterPoint Energy-owned Hillje Substation.

Learn about the need for the project, the approval process, and how to participate in the Public Utility Commission of Texas proceeding.

Frequently Asked Questions

What is CenterPoint Energy’s Proposed 345 kV Transmission Line within Wharton County?

This project is a 345-kV single-circuit transmission line on double-circuit capable structures proposed to be built by CenterPoint Energy Houston Electric, LLC (CenterPoint Energy or the Company) between EDF Renewables Development, Inc.’s (EDF Renewables) planned Space City Solar Interconnection Substation and CenterPoint Energy’s Hillje Substation in Wharton County, Texas. The need for and route of the project is subject to approval by the Public Utility Commission of Texas (PUC).

Why is the Proposed 345 kV Transmission Line within Wharton County needed?

Transmission lines are an essential part of the facilities necessary to deliver electricity to residents, businesses, and governmental entities throughout Texas. The proposed 345 kV Space City Solar Project is needed to provide direct interconnection for EDF Renewables’ new generation facility known as Space City Solar. The Space City Solar Generation Facility will consist of 175 photovoltaic solar inverters with an aggregated total output of 610.64 MW. The new Space City Solar Generation Facility will be interconnected to the CenterPoint Energy-owned 345 kV Hillje Substation.

Where will the Proposed 345 kV Transmission Line be located?

The transmission line will be built between EDF Renewables’ planned Space City Solar Interconnection Substation and CenterPoint Energy’s Hillje Substation in Wharton County. CenterPoint Energy hired POWER Engineers, Inc. to gather information about the area and prepare a routing study and environmental assessment. Using that information, CenterPoint Energy and POWER developed 7 proposed alternative routes for the new transmission line. The proposed alternative routes are located entirely within Wharton County and range in length from 3.5 to 8.0 miles.

What is the process for approval of the Proposed 345 kV Transmission Line by the PUC?

CenterPoint Energy filed its CCN application for the project with the PUC on December 17, 2020, and the PUC is required to make a determination on the project within one year of filing.

Who is CenterPoint Energy Houston Electric, LLC?

CenterPoint Energy Houston Electric, LLC (CenterPoint Energy or the Company) maintains the wires, towers, poles, and electric infrastructure serving more than two million end-use customers in a 5,000-square-mile electric service territory in the Houston metropolitan area. While the Company’s employees ensure the reliable delivery of electricity from power plants to homes and businesses, the Company neither generates nor sells the electricity to customers. The Company is an indirect, wholly-owned subsidiary of CenterPoint Energy, Inc.

Headquartered in Houston, Texas, CenterPoint Energy, Inc. is a domestic energy delivery company that includes electric transmission & distribution, power generation and natural gas distribution operations. The company serves more than seven million metered customers in Arkansas, Indiana, Louisiana, Minnesota, Mississippi, Ohio, Oklahoma and Texas. With approximately 9,600 employees, CenterPoint Energy, Inc. and its predecessor companies have been in business for more than 150 year

What is the Public Utility Commission of Texas (PUC)?

The Public Utility Commission of Texas (PUC) is the state agency created by the Texas Legislature to regulate the rates and services of electric, telecommunication and water utilities throughout the state.

What are transmission lines?

Transmission lines are a part of the interconnected power system that moves electricity from generators to substations, where the electricity is reduced in voltage and then delivered to end-use consumers over the distribution system that connects to businesses and homes. Transmission lines are larger, operate at higher voltages, and typically convey electricity over larger distances. Distribution lines are smaller, operate at lower voltages, and convey electricity over shorter distances within cities and neighborhoods.

What are the considerations involved in selecting a route for the transmission line?

The PUC considers many factors in deciding whether to approve a proposed transmission line as prescribed by state law and PUC rules, including community values, recreational and park areas, historic and aesthetic values, and environmental integrity. They also consider specific routing criteria for new lines, including whether the route utilizes or parallels compatible rights-of-way such as following existing transmission lines, roads, pipelines, property lines, natural features, and cultural features. CenterPoint Energy provided information about these factors for each of the proposed alternative routes in its CCN application.

What type of structures will be used on the new transmission line?

CenterPoint Energy has proposed that the typical structures for all proposed alternative route segments will be double-circuit capable steel lattice towers with a vertical phase configuration in a 100-foot wide ROW, or double-circuit capable steel poles with a vertical phase configuration in a 100-foot wide ROW. Depending on the terrain and other considerations, such as the length of span between structures and clearance requirements needed to cross rivers, wetland areas, FAA determinations or utility and roadway crossings, CenterPoint Energy may require different ROW widths and alternative structure types, such as flat-tap tubular steel poles with a horizontal configuration in a 180-foot wide ROW to approach and dip under existing transmission lines. The exact location or extent of the different ROW widths or the use of different structures types cannot be determined until a route is approved, surveys are conducted, and more detailed engineering designs are completed. The PUC will determine the typical structure type during the CCN process.

What is the estimated schedule for the Space City Solar Generation Interconnection Project?

CenterPoint Energy filed the CCN application for the project with the PUC on December 17, 2020, and the PUC has one year to make a decision on the project. The estimated schedule for the Project is as follows:

Estimated Dates of: Start  Completion 
Right-of-way and Land Acquisition 02/2021 11/2021
Engineering and Design 02/2021 08/2021
Material and Equipment Procurement 05/2021 01/2022
Construction of Facilities 02/2022 05/2022
Energize Facilities 06/2022 06/2022

These dates are estimates and subject to change based on the length of the PUC process, time needed to complete right-of-way acquisition and detailed engineering design, and construction conditions.

What is the estimated cost of the project?

The cost estimates for the seven proposed alternative routes range from approximately $23 million to $71 million. These estimates reflect costs for line routing to mitigate impacts to people, the environment, and other land uses. The costs also reflect structure design to address soil and coastal wind conditions. Furthermore, the cost estimates are based upon the best available information at the time the Company prepared its CCN application. These activities could reveal information that requires changes in design and construction that would likewise impact costs. Additionally, changes in market conditions could change the costs for materials and labor beyond what has been accounted for in the estimates and contingency amounts.

Will the power that flows across the new transmission line come only from the Space City Solar Generation Plant?

Yes. Initially, the transmission line will only transport power from the Space City Solar Generation Plant to the Company’s Hillje Substation, where the power can then flow to the CenterPoint Energy Houston Electric system and the entire ERCOT transmission grid. ERCOT manages the flow of electric power to more than 26 million Texas customers, representing about 90 percent of the state's electric load. As the independent system operator for the region, ERCOT oversees activities related to the reliable and safe transmission of electricity by scheduling power on an electric grid that connects more than 46,500 miles of transmission lines and more than 680 generation units.

How will CenterPoint Energy compensate landowners if it is necessary for the transmission line to cross their property?

CenterPoint Energy will make a bona fide offer to the landowner when purchasing right-of-way following the requirements of Texas law and will provide landowners with a copy of the State of Texas Landowner’s Bill of Rights. In cases where the parties do not agree on the value of the property, the land value will be determined in a condemnation proceeding where special commissioners, appointed by a judge, will determine the value of the property following a hearing where all interested parties are entitled to provide evidence of valuation.

CCN Application Documents  (Docket #51568)

PUC Documents

Landowner's Bill of RightsLandowner's Bill of Rights

Protesor FormProtestor Form

Intervenor FormIntervenor Form

Landowners and Transmission Line Cases Brochure

Electric & Magnetic Fields (EMF)

CenterPoint Energy EMF Information

Other Related Links

Public Utility Commission of Texas

Contact Us

Wes Padgett
Space City Solar CCN Project Manager, CenterPoint Energy

Policy & Compliance, CNP-T 14th Floor 
P.O. Box 1700
Houston, Tx 77251-1700

Phone: (713) 207-7155
Send email

Last updated: 
December 17 2020

Additional information related to the project will be added to this page as it becomes available. Please check back regularly for updates.