Duke-American Transmission Co.

We bring together the strengths of two leading electric industry companies to build, own and operate new electric transmission facilities throughout North America.


Who is proposing the Zephyr Power Transmission Project?

The Zephyr project is owned by Zephyr Power Transmission, LLC, which is a wholly-owned subsidiary of Duke-American Transmission Co.  DATC is a partnership that combines the experience of two electric utilities – Duke Energy and American Transmission Co. – to build, own and operate new electric transmission facilities in North America. Duke Energy and ATC share the same vision for transmission development that:

  • Increases market efficiency,
  • Improves access to the wholesale electricity market for local distribution companies, which can pass savings on to electric consumers, and
  • Supports public policy energy goals by cost-effectively bringing high-quality renewable resources to market.

Duke Energy is the largest electric utility in the U.S. with 49,500 MW of generating capacity and 31,900 miles of transmission lines serving more than seven million customers. ATC is the nation’s first multi-state transmission-only utility; it operates more than 9,600 miles of transmission lines and 554 substations.

Who is developing the wind energy to be carried on the Zephyr Project?

The Zephyr Project will carry wind energy from Wyoming, including Pathfinder Renewable Wind Energy, LLC in Chugwater, Wyo. Pathfinder includes approximately 150,000 acres and more than 3,000 megawatts of planned wind capacity in Wyoming. Pathfinder brings a visionary approach to green energy production, as their plan protects cultural and historic treasures and enhances wildlife and recreational resources while building local economies. Pathfinder is an integral component in reaching the renewable energy goals of states in the southwestern U.S., and America’s national interest in energy independence.

Who will pay for the costs of construction and operating the Zephyr Project?

The Zephyr project is a merchant transmission project, which means the developers assume market risk and have no customers from which to recover project costs. Construction and operating costs will be financed by Zephyr. After the line is in service, recovery of that investment will be included as part of the energy cost to the purchasers of the wind energy delivered by the Zephyr project.

Why is the Zephyr Project needed?

The Zephyr Project will help meet growing demand for renewable energy and help southwestern states meet their renewable energy goals – including renewable energy resource, reducing costs to consumers and energy independence. In doing so, Wyoming will further develop its wind resources.

The Zephyr Project will also strengthen the southwestern electric grid for decades to come.

  • To facilitate renewable energy – Southwestern states have renewable portfolio standards (RPS) that require utilities to provide electricity from renewable energy resources like wind. The Zephyr project will help southwestern states meet these RPS goals.
  • To sustain growth – the Southwest is expected to experience substantial long-term growth, which increases energy demand and transmission capacity to meet that demand.

How is Zephyr different from the TransWest Express Transmission Project? Are both lines needed?

Zephyr and TransWest have similarities but are not the same. The Zephyr project will connect to the Pathfinder Renewable Wind project, and TransWest would connect to a different wind project. Wyoming wind resources are vast enough to support multiple projects. In addition, the need for renewable energy in the southwestern U.S. is great, enough to support multiple projects, and southwestern states’ renewable portfolio standards are increasing.

How will communities located along the Zephyr Project benefit?

Communities along and near the Zephyr Project will primarily benefit from economic activity during construction and from property taxes over the life of the project. Every $1 spent on the Zephyr Project will produce measureable economic benefits for communities. The Zephyr Project will generate significant spending in local communities during construction, including materials and equipment purchases, real estate payments and fees and sales and use taxes.

How many jobs will be created by the Zephyr Project?

The Zephyr Project will create hundreds of jobs during the three to four years of construction, possibly including local hire opportunities. The project will also require operations and maintenance jobs over its 40-year life.

What is an energy corridor?

An energy corridor is a linear tract of land identified as a preferred location for existing and future utility rights-of-way, including for electric transmission lines, pipelines and related infrastructure.

What is the approval process for the Zephyr Project?

Zephyr is working closely with state, federal and local permitting agencies to design and develop a transparent, timely and efficient siting and permitting process. Zephyr is encouraged by numerous efforts to help facilitate coordination of federal agencies with responsibilities in permitting and siting of transmission and renewable energy projects in the west, including:

  • Department of Energy Rapid Response Team efforts to help facilitate permitting and siting of transmission infrastructure projects
  • Bureau of Land Management has given priority status to 18 renewable energy projects in 2011 – representing about 4,279 MW
  • Efforts to streamline the federal permitting review of transmission projects into a single-environmental review document by codifying the 2009 transmission memorandum of understanding signed by nine federal agencies

What is the National Environmental Policy Act (NEPA)?

The National Environmental Review Act (NEPA) is a federal statute that contains procedures to ensure that federal agency decision makers take environmental factors into account. The two major purposes of the NEPA process are citizen involvement and better informed decisions. NEPA establishes national environmental policy and goals for the protection, maintenance and enhancement of the environment as well as provides a process for implementing these goals within the federal agencies. NEPA also establishes the Council of Environmental Quality and requires an environmental impact statement on all major federal actions significantly affecting the quality of the human environment.

What is scoping?

Scoping is an early and open process to determine potential significant issues to be addressed in the Environmental Impact Statement (EIS). It is the first opportunity within the NEPA process for the public to identify project issues and alternatives.

What is an Environmental Impact Statement (EIS)?

An EIS examines physical and biological resources, resource uses, fire management, special designations, and social and economic conditions. It is the comprehensive end product of the NEPA process that analyzes the impacts of a major federal action that may significantly affect the quality of the human environment. When complete, an EIS is a tool for decision making, as the EIS describes the positive and negative environmental effects of a proposed action, describes alternative actions and provides an analysis of environmental impacts and ways to mitigate such impacts across all considered alternatives.

What opportunities will the public have to participate in the NEPA process?

There are multiple opportunities for the public to participate in the NEPA process, including:

  • The project’s scoping period
  • Following submission of a draft EIS – during the 45-day comment period there may be public meetings or hearings
  • The public can participate as an individual, by working with other individuals or organizations, or by working through local, tribal or state government
  • The public can also participate by working with local experts to assist in your review or form study groups to review the EIS and/or public comments
  • When the agency prepares its NEPA procedures
  • Prior to and during preparation of a NEPA analysis
  • When a NEPA document is published for public review and comment
  • When monitoring the implementation of the proposed action and the effectiveness of any associated mitigation

For more information on the NEPA process, see the Citizens Guide to NEPA.

If a project could have environmental impacts, the public has opportunities to comment during the scoping period, after the draft EIS is issued and following publication of the final EIS.

Will the states crossed by the proposed route have a role in permitting of the Zephyr Project? What about the counties?

Yes, states will have a permitting role. In states like Colorado and Utah, the counties will also have permitting roles.

What role does the Federal Energy Regulatory Commission play?

The Federal Energy Regulatory Commission will have oversight of the terms and conditions of service and the rates charged. It will also ensure that the Zephyr project is operated on a non-discriminatory basis.

How will Zephyr acquire right-of-way if the Zephyr Project is approved?

About 60 percent on the Zephyr Project is located on federal land.  This will be part of the permitting process.  On private land, Zephyr will negotiate with impacted landowners to get an easement which allows for the construction and maintenance of the transmission line. Learn more about how DATC acquires easements.

How wide will the right-of-way be?

The width of the right-of-way depends on the voltage of the lines and the height of the structures carrying the lines. An HVDC line carrying 500 kilovolts would require an average right-of-way of 250 feet. The right-of-way must be clear of tall-growing trees and structures that could interfere with reliable and safe operation.

How will DATC compensate landowners for easements?

If an easement is needed on a property, a DATC land agent will meet with the landowner to discuss the property and begin negotiations for compensation for the easement.  Compensation is based on the property’s fair market value, which can be determined through a sales study, through an appraisal or by examining comparable sales data.  DATC’s compensation offer will be based on the specific impact to the individual property, and is not a general number or fee.  Payments are typically made on a one-time basis.

What if the landowner doesn’t agree to grant the easement or to the compensation amount?

DATC must abide by the regulatory processes that cover public and private lands. If DATC has satisfied the regulatory requirements, we will then pursue the necessary land rights.  DATC strives to work with landowners to find a mutually agreeable payment.  If we cannot reach an agreement, there are state defined processes to determine the value of the easement.

Will the easement decrease the value of the property?

The value of a property is considered in the easement negotiation process and landowners will be compensated for an easement.  Extensive independent research has found that transmission lines have little negative impact on property values.  Download our property value fact sheet for more information.

What is an easement and what power does it give DATC?

An easement is a publicly recorded document that outlines the rights the purchasing company has with respect the property in question.  An easement is generally perpetual, meaning it remains with the land in perpetuity and transfers with the land if there is a change in ownership.  The easement agreement will specify the width and location of the easement on the property.  Download our landowner relations fact sheet for more informaiton.

When will property owners know if DATC requires an easement on their property for this project?

The Zephyr project is currently in the pre-application phase.  DATC does not anticipate having a permitted route for at least two years.  In the meantime, DATC will continue to reach out to landowners to further refine our proposal.

What is HVDC?

High voltage direct current (HVDC) power lines are the most cost-effective, efficient and environmentally favorable means of moving large amounts of electricity distances greater than 500 miles. That’s because HVDC lines can move significantly more electricity over longer distances than traditional, alternating current (AC) transmission lines. HVDC lines also lose less energy in transit than their AC counterparts. HVDC lines have been around since the 1930s; there are more than 20 HVDC transmission lines in the United States. Learn more about HVDC lines.

What types of structures can be used on the Zephyr Project?

The structural differences between traditional AC transmission lines and high voltage direct current lines are minimal. In general, HVDC lines use less wire (two vs. three conductors, thinner conductors) to move the same amounts of electricity as traditional AC transmission lines.

Structure design alternatives will be developed for the Zephyr Project during the detailed design phase of the project, but the structure height is currently estimated to be 100-125 feet. Click here for a photo of a typical HVDC structure.

What is a converter station?

Converter stations are located at the ends of a direct current line that connect the DC line to the AC transmission system. Converter stations look similar to a typical electric substation; however, an additional building houses the converter valves. Each converter station requires between 40 and 60 fenced acres.

Where would the converter stations be located?

Converter stations will be located at both ends of the Zephyr Project: one in Chugwater, Wyo., and another in Eldorado Valley south of Las Vegas. Exact locations have not yet been determined.

Can the line be built underground?

Electric transmission lines are rarely placed underground because of considerably higher installation and repair costs as well as the greater environmental disruption when the lines are built. Underground transmission lines can cost 10-20 times as much as equivalent overhead lines, with factors influencing the cost usually being site-specific. Learn more about underground transmission lines.