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What is the Centennial West Clean Line?

The Centennial West Clean Line will strengthen the nation’s critical electrical infrastructure and power our homes, communities, and the clean energy economy. The project will consist of an approximately 900-mile, overhead, direct current (DC) transmission line. The line will be capable of transmitting up to 3,500 megawatts of new renewable energy from northeastern New Mexico and Arizona to communities in California and other states in the western United States.

Who is Clean Line Energy?

Clean Line Energy is an independent transmission company solely focused on providing transmission solutions to connect clean energy with consumers.

While the United State has some of the best and most cost-effective renewable resources in the world, they are predominately located far from population centers. The challenge lies in transporting the energy generated from these resources to the communities that need the power. Clean Line is addressing the challenge by developing the Centennial West Clean Line and three other direct current transmission lines.   

Clean Line’s leadership team  includes executives who have managed, built, and financed ambitious renewable and traditional energy projects around the world. They have helped shape energy policy and advance renewable energy development at the local, state, and national levels.

What will the project cost and how will the Centennial West Clean Line be funded?

Transmission is part of the costs to deliver wind and any other form of energy to market.  The Centennial West Clean Line is estimated to cost $2.5 billion. Clean Line’s model of selling transmission capacity requires that Clean Line fund the development costs of the project and the renewable energy generators and utilities that purchase transmission capacity on the line will pay for usage of the Centennial West Clean Line.

What is Centennial West Clean Line LLC?

Clean Line Energy Partners is developing several projects across the United States – each dedicated to connecting the country’s best renewable energy resources to communities and cities with a demand for renewable power. Centennial West Clean Line LLC is a subsidiary of Clean Line Energy Partners LLC.

What is the transmission capacity of the line?

The Centennial West Clean Line will consist of an overhead, direct current transmission line that will be capable of transmitting up to 3,500 megawatts of energy. The project will deliver enough clean, renewable energy to meet the needs of over 1.9 million American homes.

What is the timeline of the project?

The Centennial West Clean Line is expected to take between five and seven years to complete. Outreach, permitting, regulatory work and right-of-way work will take three to five years and construction will require approximately two or three years.

When is construction scheduled to begin?

The Centennial West Clean Line is now in the early stages of development and is expected to take between five and seven years to complete. Construction is slated to begin around 2020.

What is the route of the transmission line?

Clean Line is developing the Centennial West Clean Line in a methodical, transparent and collaborative manner and will work with landowners, American Indian tribes, environmental agencies and community officials in order to come up with the best route possible.  Siting a new transmission line is a lengthy and complex process that requires the evaluation of many factors and interests. Clean Line has already met with many federal, state and local governmental-elected officials, community leaders and environmental advocates, as well as the officials with Forest Service, Bureau of Indian Affairs, and numerous state agencies, such as the New Mexico Renewable Energy Transmission Authority, to obtain their input on the best route from an environmental and land use perspective. Clean Line will conduct an extensive public outreach process that will include working with communities, landowners, American Indian tribes and other stakeholders to determine the best route for the transmission line. Clean Line believes that such a process, where input is sought from those affected by the project, is critical to the ultimate success of the Centennial West Clean Line.

Is Centennial West involved with the Western Electric Coordinating Council?

Centennial West Clean Line is a member of the Western Electricity Coordinating Council (WECC), WestConnect and the Southwest Area Transmission (SWAT) sub-group.  Members of the Centennial West Clean Line project team attend and participate in transmission planning open stakeholder meetings. These forums allow various entities to discuss where the electric grid will be in 10-20 years and how it will incorporate renewable energy, reliability, emissions reductions, network upgrades and additional changing policies.

The various planning groups at WECC also have tribal representatives and provide a forum for more discussions and opportunities.  Centennial West is also working closely with various Federal and State initiatives to promote Tribal renewable energy development.

Who will manage the development of the Centennial West Clean Line?

The project is managed by a team of Clean Line’s employees who have developed, built and financed ambitious projects in the renewable and traditional energy sectors, as well as senior policy professionals who shaped energy policy and advanced the renewable energy agenda at the state and national levels. To learn about the Clean Line team, please click here.

Who will build the Centennial West Clean Line?

Construction of new electric transmission and wind and solar generation in such close proximity to manufacturers in New Mexico, Arizona, Nevada and California will increase business opportunities for companies in those states. Wind and solar generation developers will select their own suppliers and construction contractors.

Clean Line will select a firm to provide development support and engineering, procurement, and construction services (EPC) for the Centennial West Clean Line. Clean Line is committed to using qualified local and regional contractors to build the transmission line and encourages local businesses interested in working on the construction and maintenance of the project to submit their business information by clicking here.

Who will operate the Centennial West Clean Line?

Centennial West Clean Line LLC will be responsible for all maintenance of the line. Like many other transmission lines, the Centennial West Clean Line will likely be controlled by one of the regional transmission organizations (RTO) or independent system operators (ISO).  RTOs or ISO are responsible for planning and coordinating the transfer of energy over large interstate areas. An RTO/ISO controls and monitors an electricity transmission grid that is larger and uses much higher voltages than the typical power company’s distribution grid.

Who will benefit from the Centennial West Clean Line?

People and communities across the project area will benefit from the Centennial West Clean Line. Consumers in the Southwest— residential, rural customers and businesses—will benefit from the lower prices resulting from the increased competition that the project will bring.  Additionally, the project will create jobs across all four states—California, New Mexico, Nevada and Arizona—through the actual construction of the transmission line, through the manufacturing of the components for the transmission line, and through the construction and manufacturing of the wind turbines needed to supply the line. Furthermore, local governments across the project area will typically benefit from increased tax revenues from both the transmission line infrastructure and the supporting solar and wind farms, and landowners at the resource end of the project area will benefit from royalty payments associated with wind and solar farms.

How many jobs will the Centennial West Clean Line create?

The Centennial West Clean Line will bring substantial economic benefits throughout the project region. It is estimated that the Centennial West Clean Line will result in more than 5,000 construction jobs and more than 500 permanent jobs maintaining and operating the transmission line and the associated wind and solar farms. Additionally, businesses, particularly those involved with services, materials and equipment to be used in construction of the project and the associated wind farms, as well as retail and hospitality industries, will see increased demand for their products and services.

Is Clean Line a regulated or unregulated entity?

As a transmission owner and operator, Centennial West Clean Line LLC will be regulated by the Federal Energy Regulatory Commission (FERC).  In addition, Centennial West Clean Line LLC will be required to obtain permits from a variety of state and federal agencies.

Centennial West Clean Line LLC is committed to working with  federal and state commissions and agencies that may have jurisdiction over the project, including: the New Mexico Renewable Energy Transmission Authority, Western Area Power Administration, State Public Utility Commissions and Federal and State environmental agencies.

Will the Federal Energy Regulatory Commission (FERC) be involved in the approval of this project?

Federal Energy Regulatory Commission (FERC) will have oversight of the terms and conditions of service and the rates charged and will ensure that the project's transmission lines are operated on a non-discriminatory basis.

What is the National Environmental Policy Act (NEPA)?

NEPA requires federal decision-makers to consider how federal actions may impact the environment including natural, cultural, and socioeconomic resources.  Following identification of a preferred route and alternative routes, Clean Line plans to complete an Environmental Impact Statement (EIS) under NEPA. The EIS will discuss the purpose of and need for the project, alternatives, the affected environment, and the environmental consequences of the proposed project. NEPA also requires extensive public input and involvement. Stakeholders will be able to submit comments, questions, and inquiries to the designated lead federal agency throughout the NEPA process.  These comments, questions, and inquiries will be taken into account and recorded.  Early in the process, public scoping meetings allow the public the opportunity to provide input on what issues should be addressed in the Draft EIS.  Later, public comment meetings allow the public to comment on the findings of the Draft EIS. To visit the Environmental Protection Agency's NEPA website, please click here.

Who is considered to be a stakeholder of the Centennial West Clean Line?

A stakeholder is defined as any person or organization interested in the Centennial West Clean Line, including, but not limited to: individual landowners; federal, state and local government entities and agencies; tribal organizations; elected officials; local businesses and business organizations; nongovernmental organizations; environmental and advocacy groups; transmission planners; and civic and community organizations.

How will Centennial West Clean Line acquire right-of-way for this project?

The project will use a stakeholder outreach process that is methodical, responsible, transparent, and compliant with federal and state laws and regulations. Right-of-way agreements will be negotiated individually with each landowner, including federal and state agencies, and will depend on many factors including, but not limited to:

  • Existing uses of the land (e.g., crops vs. grazing vs. residential)
  • Type and number of structures that will be placed on the land
  • The requirement for future access rights to the land
  • Environmental conditions

Our team of professionals and consultants are experienced in the industry, particularly in building relationships with landowners. It is our goal to work proactively with the communities and landowners who will be affected. We will be available to address stakeholders’ concerns at every point throughout this process. Clean Line requires that all of its representatives follow a Code of Conduct, which provides each representative treat every landowner with consideration and respect. In addition, Clean Line strives to build and maintain long-lasting relationships with all landowners and stakeholders by working in a respectful and collaborative manner for the life of the project.

Can I use the land under the transmission line for ranching, growing crops or other purposes?

The land under the transmission line can typically be used for crop production and pasture/grazing lands. Clean Line must comply with the National Electric Safety Code to ensure the safety of the general public and North American Electric Reliability Corporation Standards to ensure the reliable operation of the transmission line. As a result, there are restrictions on the placement of structures and planting tall growing trees underneath the transmission line.

Can I hook solar panels or a wind turbine up to the line?

It is not feasible to tie in wind or solar energy along the route of the DC line because the intermediate collection points are very difficult to justify economically. The DC converter stations that connect the AC grid to the DC line cost approximately $250 million each. Think of DC lines as “express” lines, suitable for long-haul transmission of electricity but not for short distances. DC lines are typically the best choice for distances over several hundred miles.  In the case of the Centennial West Clean Line, the wind and solar energy facilities will connect at the eastern end of the line in New Mexico, and possibly at one midpoint converter station in Arizona, and the energy will be delivered directly to southern California at the other end of the DC line.

Can I get my electricity from the line?

The electricity transmitted by the Centennial West Clean Line is a much higher voltage than the local transmission and distribution grid that provides electricity to homes and businesses. Therefore, end users cannot get their electricity directly from the project, but rather must rely on their utilities to supply power at appropriate voltage levels. The renewable power delivered by the Centennial West Clean Line will be delivered to consumers through the existing transmission and distribution grid.

What is DC?

DC stands for direct current. The electric grid is made up almost exclusively of alternating current (AC) transmission and distribution lines. DC is widely considered the most efficient method to connect large amounts of energy to distant electricity areas that have a strong demand for the power. DC lines can transfer significantly more power with greater efficiency than comparable AC lines.  For more information about DC, click here.

Is DC a new technology?

Direct-current (DC) transmission is a proven technology that has been around since the 1930s and the birth of the modern electric industry. DC is already in use in the United States and throughout the world. Currently, there are more than 20 DC transmission facilities in the United States and more than 35 across the North American grid.

What are the advantages of DC technology?

Direct-current (DC) transmission lines have smaller structures and require less land than AC lines to deliver an equivalent amount of energy. From a power grid operator perspective, DC gives grid operators complete control of energy flow. DC lines are not a replacement for the AC grid or the additional AC transmission that is required. DC complements the existing AC transmission network and can be an additional source for system stability and reliability.

Why is Clean Line using DC technology for its projects?

Direct-current (DC) is the preferred technology for moving large amounts of power over long distances. The use of an DC transmission line results in overall higher efficiency and reliability than an equivalently sized alternating current line to move the same amount of power, therefore offering significant electrical, economic and environmental advantages. These advantages include lower power losses on the line, better land use due to smaller tower structures, and the ability to control the power flow.

What will the structure of the transmission line be?

There are many factors that must be considered when determining the structures including terrain requirements and land-use constraints (for instance center pivot irrigation systems). Clean Line is currently analyzing a variety of structures ranging from steel monopole structures, steel lattice designs, guyed structures and hybrid steel-concrete structures. Ultimately, we value landowner input and will take the landowners’ feedback and preference into consideration to select the structures. Preferred structures will not be known until final route determination.

How wide is our right of way (ROW)?

Right-of-way refers to the actual land area acquired for a specific purpose, such as the location for a transmission line. Clean Line will be acquiring easements and the land underneath the wires will be able to be utilized by the landowner for certain activities such as farming, grazing cattle, and other activities that do not interfere with the operation of the line. When determining the width of the right-of-way, it is necessary to understand the amount of space needed for appropriate safety clearances to the ground and for the side-to-side movement of conductors due to wind. Clean Line estimates the right-of-way for its projects will generally be between 150 and 250 feet; this is largely determined by how closely structures are placed to each other, terrain and clearance issues. The closer the structures are to one another, the more narrow the right of way, but that also means more structures.

How big is a converter station?

The converter station for an DC transmission line looks similar to a typical electric substation; however, there is also a building that hosts the converter valves in an enclosed environment. The converter station will take up between 40 and 60 fenced-in acres and is typically located near its point of interconnection to the AC grid.

What is EMF?

EMF stands for electromagnetic field. Electric fields are produced by voltage and voltage is the electrical pressure that drives an electric current through a circuit. Magnetic fields are produced by current and current is the movement or flow of electricity. EMFs are naturally present in the environment and are present wherever electricity is used, for example a toaster, cell phone, wristwatch, lamp, computer, etc. The earth has both magnetic fields produced by currents in the molten core of the planet and an electric field produced by electrical activity in the atmosphere, such as thunderstorms. For more information about electric and magnetic fields, please click here.

What efforts is Clean Line initiating to minimize environmental impact?

Clean Line is working extremely hard to be a good environmental steward. We are conducting extensive outreach to environmental advocate organizations and other similar organizations to get input as to areas of concern.  We are accountable to state and federal agencies regarding our environmental impacts.

Can’t California meet its Renewable Portfolio Standard (RPS) and carbon reduction (AB 32) goals entirely with in-state solar energy?

California has excellent renewable energy sources within its borders.  In particular, California has some of the best solar resources in the country and is making progress towards developing them; however, California would still benefit from out-of-state wind power for several reasons:

  • Solar energy is still an expensive form of power.  At its cheapest, large-scale solar costs utility companies around $100 per megawatt-hour (MWh) to buy.  A megawatt-hour is a quantity of energy able to power around 1000 homes for one hour.  The cost of generating wind energy in New Mexico and transmitting it to California is about $50 to $60/MWh.
  • According to the California Public Utilities Commission (CPUC), to generate 33% of California’s electricity from renewable sources would require wind power to provide 25 to 50 percent of this renewable energy.
  • Solar power can only be generated during daylight hours.  Even when combined with storage technologies, the energy source is unavailable for several hours every night and early morning.  Wind energy can be available at any hour of the day, and in many areas it blows strongest during nighttime hours.  This also makes wind energy an excellent complement to electric vehicles, which would tend to charge over night.
California has lots of wind, too. Why not mix California solar with California wind?

California wind will be part of any effort to meet state RPS and carbon reduction goals, but lower costs and an abundance of exceptional resources make out-of-state wind an option well worth including:

  • Analyses by the California Air Resources Board (ARB) and the CPUC have shown that including more out-of-state wind energy is the least expensive way for the state to meet its carbon reduction goals under California Assembly Bill 32 and the 33% RPS. (1)
  • According to the CPUC, meeting renewable energy and carbon-reduction goals will require a minimum of 25 terawatt-hours (TWh) of wind energy, with some scenarios requiring up to 50 TWh.  A terawatt-hour is enough energy to power 115,000 homes for one year.  California currently generates about 10 TWh of wind energy each year, meaning production would need to more than double.  This additional energy would require up to 11,500 MW of new wind farms or 15,220 MW of new solar plants. (2)  Importing some of this energy would be cheaper than building it all in California.
  • The National Renewable Energy Laboratory estimates that New Mexico, which 80% of California's land area, has about 10 times as much land with an exceptional wind resource as California does (an exceptional wind resource is defined as an area with a 40% or higher gross capacity factor).


1 California Public Utility Commission“33% Renewable Portfolio Standard Implementation Analysis Preliminary Results.”June 2009; California Air Resource Board “Impact Assessment of the 33Percent Renewables Energy Standard.” June 2010.

2 Assumes a 40% NCF for wind, 30% for solar

Why can’t California meet its energy needs with rooftop solar panels, which don’t require disturbing wildlife habitats and areas of natural beauty?

Rooftop photovoltaic solar is a great way to generate clean energy, but it may not be affordable for many Californians:

  • The total cost to a consumer of generating his or her electricity from a rooftop solar panel is about three times as much as he or she would pay for wind energy generated in New Mexico and transmitted to California.
If the Centennial West Clean Line doesn’t get the environmental approval it needs, will the costs still get passed on to electricity customers?

Not at all.  Clean Line and its investors bear all the risk for the development of the Centennial West Clean Line. If utilities decide they want more expensive in-state solar, ratepayers aren’t on the hook for any Centennial West Clean Line costs.

Does Clean Line have an Avian Program?

Yes. The goal of Clean Line’s Avian Program is to advance progress towards electric transmission systems that are safer for all avian species. The Avian Program establishes a framework for reducing risks to birds and describes Clean Line’s policy to develop and implement Avian Protection Plans specific to each transmission system.  To read and download Clean Line Energy Partners’ Avian Program, please click here.

What is an Avian Protection Plan?

An Avian Protection Plan, or APP, describes specific ways to reduce the operational and avian risks that result from avian interactions with electric utility facilities. Clean Line’s Avian Protection Plans will consider specific habitat types, species, and system components when evaluating potential risks. Each APP will also identify avoidance, minimization, and mitigation measures to address avian risk for each transmission system. To learn more about Avian Protection Plan guidance, please see the Avian Powerline Interaction Committee’s website here.

What is the Avian Power Line Interaction Committee?

The Avian Power Line Interaction Committee (APLIC) leads the electric utility industry in protecting avian resources while enhancing reliable energy delivery. The members consist of over 50 utility companies, wildlife resource agencies, conservation groups, and manufacturers of avian protection products that work together to understand the causes of bird/power line electrocutions and collisions and to develop ways of preventing bird mortalities and associated power outages.  To learn more about APLIC, see www.aplic.org.

What is the Dedicated Metallic Return Conductor?

Under normal operations a bi-pole high voltage direct current (HVDC) transmission line requires a return path for very small current imbalances.  During emergency operations or certain maintenance operations when one pole is out of service, the full load current will flow through this return path.  In some existing HVDC transmission lines, this return path is via ground electrodes.  The Centennial West Clean Line project will utilize a third set of conductors (wires) on the transmission structure referred to as the dedicated metallic return conductor.  Therefore, during bi-pole or monopole operations, all current will be contained within conductors on the project.