About Clean Line Energy

Who is Clean Line Energy?
  • Clean Line Energy is an independent transmission company solely focused on providing transmission solutions to connect clean energy to communities and cities that have a need for low-cost renewable power. While the United States 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 Plains & Eastern Clean Line and four other long distance transmission lines. Clean Line’s leadership team has managed, built, and financed ambitious renewable and traditional energy projects around the world.
Who owns Clean Line Energy?
  • Clean Line Energy is supported by investors who bring long-term perspective, patient capital and an understanding of the complexity of siting and building long distance, interstate infrastructure projects. Clean Line’s investors include the Houston-based Zilkha family, funds associated with ZBI Ventures, National Grid and Bluescape Resources.
  • National Grid is one of the largest investor-owned energy companies in the world, with extensive experience building, owning and operating large HVDC electricity transmission interconnectors and transmission networks in the US and the UK. National Grid shares Clean Line’s vision of enabling a cleaner energy future by investing in transmission projects that facilitate the development of renewable energy resources.
  • Bluescape Resources is a private, independent energy investment and operating company. Bluescape’s executive chairman served as CEO of TXU from 2004-2007. At the time, TXU Electric Delivery Company operated the largest transmission & distribution system in Texas.
  • ZAM Ventures is associated with the Ziff family-owned private investment firm that focuses on private equity investments in, among other sectors, the energy and energy-related sectors.
What is the Clean Line team’s experience with developing and constructing electric transmission infrastructure?
  • One of our investors, National Grid, has extensive experience building, owning, and operating large HVDC transmission facilities in the US and the UK.
  • Clean Line is developing four other transmission lines similar to the Plains & Eastern Clean Line—each line has a similar rationale —several hundred miles long to connect the country’s best renewable resources to larger markets with a demand for low-cost clean energy. 
  • Clean Line’s team has extensive experience with developing, designing, and permitting transmission projects, wind farms, and other energy projects that have been built around the country.  

About the Plains & Eastern Clean Line

What is the Plains & Eastern Clean Line?
  • The Plains & Eastern Clean Line transmission project will deliver 4,000 megawatts (MW) of clean energy generated from the Oklahoma Panhandle region to utilities and customers in Arkansas, Tennessee, and other markets in the Mid-South and Southeast, areas that lack access to low-cost, renewable power. The project will deliver enough energy to power more than one million homes per year in the Mid-South and southeastern United States.

Is Plains & Eastern Clean Line a Regulated or Unregulated Entity?
  • Plains & Eastern Clean Line is regulated by the Oklahoma Corporation Commission and Tennessee Regulatory Authority.  As a transmission owner and operator, Plains & Eastern Clean Line will also be regulated by the Federal Energy Regulatory Commission. In addition, Plains & Eastern Clean Line will be required to obtain permits from a variety of state and federal agencies, including the U.S. Army Corps of Engineers. Plains & Eastern Clean Line must also follow the rules and requirements specified in by the United States Department of Energy’s as part of its decision to approve the project.

Will the Federal Energy Regulatory Commission (FERC) be involved in the approval of this project?
  • The Federal Energy Regulatory Commission (FERC) will have oversight of the terms and conditions of service and the rates charged and will have a role in ensuring that the project’s transmission lines are operated fairly. FERC has approved Plains & Eastern Clean Line’s rate structure and granted Clean Line authority to negotiate with potential customers.

Will the Plains & Eastern Clean Line have condemnation authority?
  • Linear infrastructure projects like pipelines, water lines, telephone lines, and electric transmission and distribution lines are sited in the public interest.  In order to assure that projects can be completed, the entities building them may have the right to condemn certain easements or to utilize eminent domain when necessary to finalize the acquisition of certain easements.
  • Plains & Eastern Clean Line, or governmental entities participating in the project (if applicable) may seek to acquire certain easements through condemnation, but only as a last resort after exhausting all reasonable attempts at voluntary easement acquisition.  
What is the overall project timeline?
  • The Plains & Eastern Clean Line is currently under development. Construction. The Plains & Eastern Clean Line is expected to begin delivering electricity as early as 2020.

Can only “clean” or renewable energy be transported on the line?
  • Clean Line’s intent is to provide new wind generation facilities access to markets with a growing demand for renewable energy, which is why we are locating the resource area converter station where wind energy is   most cost competitive. Legally, transmission companies are not allowed by the Federal Regulatory Commission (FERC) to prohibit certain types of energy, but as a practical matter, wind energy is the resource that would be economically advantaged by a project like this. It would not make sense to build a coal or nuclear power plant a long distance from a load center when you could produce the electricity much closer to the demand.

Will the project spur wind development in Arkansas and Tennessee
  • The project will not directly spur wind development in Arkansas and Tennessee.  However, these states are home to companies that produce components and equipment used in wind farms and transmission lines, and the Plains & Eastern Clean Line will likely increase demand for the products and services produced by those companies.
  • The project will support the integration of larger amounts of wind power into the electric system.  Generally, the wind does not always blow at any one spot, but it tends to be blowing somewhere.  With a robust transmission system, we can move wind energy from where it is blowing to where it is needed.  Transmission, therefore, allows more wind energy to be utilized.
Who will benefit from the Plains & Eastern Clean Line?
  • Individuals and communities across the project area will benefit from the Plains & Eastern Clean Line. Consumers in the Mid-South and Southeast—both residential customers and businesses—will benefit from the lower prices resulting from the increased competition that the project will bring. The project will support major new wind farm construction in Oklahoma, and will create jobs across Oklahoma, Arkansas, and Tennessee 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.  Oklahoma, Arkansas, and Tennessee are home to dozens of companies that serve the wind industry.
  • Additionally, local governments will typically benefit from increased revenues from both the transmission line infrastructure and the supporting wind farms. Landowners will benefit from the tens of millions of dollars that will be paid for right-of-way, and will be able to continue to use their land for agricultural production and other purposes. Citizens across the region will benefit from cleaner air and water as a result of the new wind energy enabled by the Plains & Eastern Clean Line project, as that energy will displace more polluting forms of electric generation.  For more detailed information about the benefits of the Plains & Eastern Clean Line, please click here.
Who is considered a stakeholder of the Plains & Eastern Clean Line?
  • A stakeholder is defined as any person interested in the Plains & Eastern 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; non-governmental organizations; and civic and community organizations.

About Wind Energy

Is wind power cost effective?
  • American wind power saves consumers money and makes the energy market more competitive. Wholesale electric power prices have reduced in areas of the country where wind power was added to the system. 
  • Wind power also helps stabilize consumers’ electricity rates. Due to its lack of fuel cost, wind energy protects consumers from volatility in the price of fossil fuels.
Are Clean Line’s projects dependent on federal subsidies for wind energy?
  • Clean Line is not seeking any federal or state funding.  Our projects depend on strong long-term fundamentals, one of which is that wind energy is cost competitive.  Tax policy is one factor in the cost competiveness of wind, just as it is with nuclear, coal and natural gas.  
  • There are other factors that contribute to the cost competitiveness of wind, including:
    • high wind speeds in our resource areas  
    • wind technology (with taller towers and longer blades and other improvements) continue to improve and drive costs even lower, and 
    • the public, individual states, and utilities have a strong appetite for more renewable energy.
Does wind energy still make sense if natural gas prices remain low?
  • Yes.  Natural gas will be an important part of the energy supply mix, but it should not be the only thing in the portfolio.  Americans understand this intuitively.  Most of us do not own just one stock in our retirement accounts, but a mix of different companies’ stocks and bonds.  Likewise, we buy insurance against sickness, accidents, and even death.  Think of renewable energy as an insurance policy to a very real possibility that natural gas won’t be consistently cheap for the next three decades.
  • History suggests that it is extremely risky to rely exclusively on any one form of energy.  Any consensus on long-term gas pricing and supply is a fragile one.  In a world of uncertainty driven by policy, environmental concerns, macroeconomics and geology, it makes sense to develop a diverse portfolio of energy supply.
  • After all, the costs of not having affordable energy are extremely high; in practice this means a portfolio of gas and renewable energy in our electric resource mix.  
Can wind and natural gas complement each other?
  • Yes, we need a balanced energy portfolio.  Wind can’t supply all our electricity, and modern, natural gas-fired generation is the best complement for wind energy.  Gas plants can ramp up and down quickly to deal with variability in wind generation.  Natural gas is domestically produced and cleaner than most alternatives.  Together, wind and gas can replace aging coal plants, creating a cleaner, more modern energy mix.
Does wind reduce the efficiency of fossil generation?
  • While adding new wind energy to the power supply may reduce by a very small amount the operating efficiency of a small number of fossil fuel plants, any increase in emissions from fossil fuel plants as a result of such inefficiency would be far outweighed by the decrease in emissions as a result of the displaced fossil fuel generation.
What happens when the wind stops blowing? Do the lights go off?
  • Utilities purchase renewable power to add diversity to their generation mix and meet state renewable portfolio requirements. 
  • Wind power works together with other sources of power generation that continuously respond to changes in electricity demand.  When the wind blows, wind power allows grid operators to ramp down other generators and save fuel.  Conversely, when the wind stops blowing, another generator—often a natural gas or hydropower facility—can increase its output to compensate.
  • The nation will have a diverse stream of energy resources for many years to come, including wind, nuclear, gas, coal, and other resources.
What is a capacity factor?
  • Capacity factor for a power plant is a measure of how often an electric generator runs for a specific period of time.  It compares how much electricity a generator actually produces with the maximum it could produce at continuous full power operation during the same period.  
  • A megawatt is a unit for measuring power that is equivalent to one million watts.  One megawatt is equivalent to the energy produced by 10 automobile engines.
  • A megawatt hour (MWh) is equal to 1,000 kilowatt hours (kWh).  It is equal to 1,000 kilowatts of electricity used continuously for one hour.  It is about equivalent to the amount of electricity used by about 330 homes during one hour.
  • To give an example illustrating capacity factor, if a 1 MW generator produced 5,000 MWh over a year, its capacity factor would be 0.57 because 5,000 MWh equals 57% of the amount of electricity the generator could have produced if it operated the entire year (8,760 hours) at full capacity and produced 8,760 MWh of electricity.  
  • Generators with relatively low fuel costs are operated to supply baseload power, and typically have average annual capacity factors of 70% or more. Generators with lower capacity factors may indicate that they are operated during peak demand periods and/or have high fuel costs, or their operation depends on the availability of the energy source, such as hydro and wind energy.
Where will the renewable energy that will be transported on this line come from?
  • Clean Line anticipates that the energy transported on this line will be sourced from the Oklahoma Panhandle and Texas Panhandle, within an approximately 40-mile radius of the project’s Oklahoma converter station.
Is there enough wind power being developed there to fill the capacity for the line?
  • In 2014, Clean Line conducted an open solicitation pursuant to its FERC negotiated rate authority. Clean Line received requests from fifteen different potential transmission customers for 17,091 MW of transmission service, nearly four times the Project’s total transfer capacity during the initial open solicitation window. Since then, several respondents have increased the size of their capacity requests. To date, Clean Line has received requests for a total of 22,190 MW of transmission service, over five times the Project’s total transfer capacity.

How many wind farms will connect to the line? How far away from the converter station?
  • The Plains & Eastern Clean Line will be responsible for bringing on line over 4,000 MW from new clean energy projects that otherwise would not be built due to limitations of the existing electric transmission grid. The energy may come from multiple wind farms built by different developers in the Oklahoma Panhandle region.

How will wind farms connect to the Plains & Eastern transmission line?
  • A collector system will consist of AC transmission lines that will connect the new wind generation projects radially into the converter station. 
  • Clean Line believes that development of a collection system should be conducted in concert with wind developers that will build the wind farms that will connect to the Plains & Eastern Clean Line project.  We have begun preliminary evaluation to determine where the collector system may go and how long the lines may be, but final routes will be identified at a later date, once Clean Line determines the new wind farms that will connect to the HVDC line.
  • The Final Environmental Impact Statement (EIS) for the project includes possible locations of the AC collector lines. These routes, as described in the FEIS, represent where AC transmission lines could connect the wind farms with the Oklahoma converter station.
  • The right-of-way for each AC transmission line would be 150 to 200 feet wide. In its Record of Decision, DOE did not select the final routes for the AC collection system. Rather, DOE identified the agency's preferred alternative as the construction of between four to six AC collection transmission lines within a 40-mile radius from the Oklahoma converter station. The decision notes that the specific locations of these transmission lines cannot be known at this time and will depend on the locations of future wind farms that may be constructed in the future to connect to the Plains & Eastern Clean Line project.
Can I hook a wind turbine to your transmission line?
  • The wind energy facilities that will connect to the Plains & Eastern Clean Line will be utility scale projects at the western end of the line.  Each wind farm project that connects to the line will likely be in the hundreds of megawatts.
Will the transmission line affect my ability to get a turbine on my property?
  • Generally, it is possible to route the line through a proposed or existing wind farm where necessary.
  • Wind turbines are spaced widely, with a minimum of 1,000 – 1,400 feet between each wind turbine.  The Plains & Eastern Clean Line will need about 150-200 feet of right-of-way.  For a visual depiction of how transmission lines can easily be located within or near a wind farm, please click here.
Is there a letter from ten Eastern Governors regarding Plains & Eastern Clean Line?
  • No. In 2009, ten East Coast Governors did write a letter to leaders in Congress regarding renewable energy development.  This letter was sent to express the Governors’ support for renewable energy in general, and their opposition to certain federal policies which might have favored Midwestern wind energy and transmission lines over their local resources. The policies referenced in their letter were not passed into law.
  • This letter was sent prior to the start of development of the Plains & Eastern Clean Line and does not mention Plains & Eastern Clean Line. The Plains & Eastern Clean Line is not receiving any federal subsidies for the development of the proposed transmission line. In the letter, the Governors “support the development of wind resources for the United States wherever they exist” and seek a level playing field for renewable energy development.  Plains & Eastern Clean Line’s participant-funded business model is entirely consistent with such a level playing field approach.

    Click here to read the full letter sent from the ten Eastern Governors.


How did Clean Line identify its the route for the direct current transmission line?
  • Since 2010, Clean Line has pursued a multi-step routing process that incorporates best practices for siting  linear infrastructure to avoid and minimize impacts from the project. Clean Line has conducted extensive public outreach involving landowner, community leaders, agency representatives and other stakeholders and is committed to minimizing impacts to existing land use in accordance with environmental, cultural, and engineering considerations. Clean Line believes that a process that involves seeking input from those affected  by the project is critical to the ultimate success of the Plains & Eastern Clean Line. Through direct outreach with the public and coordination with public agencies and non-governmental organizations, Clean Line solicited stakeholder input to refine and identify the proposed right-of-way for the direct current transmission line.

Will you route the line along existing transmission lines, roads, section lines, or other property lines?
  • Routing along existing linear infrastructure (such as other transmission lines, roads, and pipelines) or property lines is widely accepted as a best practice because it helps to minimize new fragmentation of existing land use and habitats; however, we must balance that with the potential impacts on land use in the area as well as other applicable criteria.

Will you build within other transmission lines or utility rights-of-way?
  • When paralleling existing transmission lines, our right-of-way would typically be adjacent to (but not overlapping) the existing rights-of-way. When doing so, Clean Line will maintain safety clearances as dictated by the National Electrical Safety Code and applicable state and local codes.

Are there any issues with crossing existing transmission lines?
  • No.  While engineering is needed, there are no prohibitive issues with crossing existing transmission lines.
  • Generally, our conductors will be higher voltage and cross above existing lines (higher voltage lines are on top, generally). Crossing locations will be determined in coordination with the owners of the existing infrastructure and applicable regulations.
What impacts do you anticipate to birds/other species?
  • We will seek to avoid and minimize impacts to wildlife habitat; our routing and siting process takes into account sensitive environmental areas and habitats.  Clean Line has an Avian Protection Plan for each project that describes measures to reduce adverse impacts to birds.  To review Clean Line’s Avian Protection Plan, please click here.
How will you get through lesser prairie-chicken habitat?
  • The long-term viability of the lesser prairie-chicken and other prairie birds is a paramount concern in areas which Clean Line is developing projects; specifically in parts of Oklahoma and Kansas.
  • Clean Line has worked with the US Fish and Wildlife Service, Kansas Department of Wildlife, Parks, and Tourism, the Oklahoma Department of Wildlife Conservation, and other stakeholders to ensure that the project avoids or minimizes potential adverse effects associated with this species and its habitat.
Do landowners have any say where the structures are placed within their easements?
  • In order to reduce the potential impact of structures on private properties, Clean Line will make reasonable efforts, consistent with design criteria, to take landowner feedback into consideration when determinding structure placements on their properties. Easement agreements will be negotiated individually with each landowner and will consider many factors including, but not limited to:
    • Existing uses of the land (e.g., crops vs. grazing vs. forested),
    • Type and number of structures that will be placed on the land,
    • The requirement for future access rights to the land, and
    • Environmental conditions.

Land Use

How wide will the right-of-way (ROW) need to be?
  • Right-of-way refers to the actual land area needed for a specific purpose, such as the easement for a transmission line. Together all the easements will make up the right-of-way for the project. 
  • Clean Line estimates that the right-of-way for its projects typically will be between 150 to 200 feet wide; though the line will directly impact much less land than that. Less than 1% of the total easement property for the project would be taken out of production if the structures are placed in farmland. 
  • The right-of-way width requirement is largely determined by how close structures are placed to each other, terrain, and clearance requirements.  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 wires due to wind.
  • Some additional areas may be necessary for lay down or access during construction; Clean Line will provide additional compensation for these areas through separate agreements with landowners.
How much room is needed for structures within the easement?
  • With either lattice or monopole structures, less than 1% of the total easement area for the project will be occupied by the structure footprints.
  • Guyed structures with supporting wires will typically occupy 10-15% of the easement area due to the space requirements of the supporting wires.

Can farming / ranching continue in the easement / under the lines?
  • Yes.  Clean Line will acquire easements, but the land will still belong to the landowners and can be utilized for activities such as farming, grazing cattle, and other activities that do not interfere with the operation of the line.
  • Farming of row crops (e.g., wheat, corn, soybeans, etc.) can continue under the lines. There will be sufficient clearance under the transmission line to grow full-height crops (up to about 10 feet tall), not including tree crops, and to operate standard farm equipment.
  • Ranching and grazing are totally compatible and will not be restricted. 
Can anything be planted in the easement area?
  • The land under the transmission line can be used for crop production and pasture/grazing lands. Most crops less than ten feet tall may be grown safely under power lines. Clean Line must comply with the National Electrical 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, vegetation growing within the easement area must be limited in height to maintain safety and reliability standards..

How close can one get to the structures/poles for farming operation?
  • Landowners will be able to farm right up to the structures.
How will Clean Line acquire right-of-way for this project?
  • Clean Line will acquire an easement from landowners. The easement grants Clean Line certain surface rights over a specific portion of the property. Landowners are not selling their land. Easement agreements will be negotiated individually with each landowner and will consider 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
  • Clean Line requires that its representatives follow a Code of Conduct, which provides that all representatives treat every landowner with consideration and respect.  In addition, Clean Line strives to build and maintain long-lasting relationships with landowners by working in a respectful and collaborative manner for the life of the project.  To read the Code of Conduct for Oklahoma, please click here.  To read the Code of Conduct for Arkansas and Tennessee, please click here.    
How much will you pay for right-of-way?
  • Clean Line Energy is committed to compensating land owners fairly.
  • The landowner compensation package will include an easement payment based on the size and market value of the easement acreage required and an additional payment for each structure placed on the landowner’s property.
  • Clean Line has gathered input from various landowners and stakeholder groups about how to compensate for right-of-way, and we will continue to work with landowners and other parties to determine the best approach for fair compensation.
  • For example, a compensation package could include:
    • An easement payment based on acreage affected and the market value of the land
    • An additional payment for each structure on a landowner’s property
    • Other payments may be made in certain circumstances, including for: 
      • Crop damage 
      • Commercially marketable timber 
      • Irrigation interference 
      • Damage to drainage tile 
  • Since some easements may be very small in size, Clean Line will pay landowners a minimum easement payment of $2,000 per parcel, regardless of the size of the easement area on their land. In the event that no structures are constructed on a landowner’s parcel, the landowner will also receive a minimum structure payment.

Will structure payments be annual or one-time?
  • Historically, utilities have made one-time payments for transmission line easements and structures.
  • During its extensive outreach efforts, Clean Line heard that landowners have a strong interest in annual payments as compensation for structures on their properties.  Therefore, Clean Line has decided to offer landowners the option of receiving for each structure on their property an up-front payment or an escalating annual payment for as long as the structure is on their easement.
  • The easement payment will be made up-front.
When will landowners receive easement payments?
  • Representatives are available to begin discussion of compensation for easements with affected landowners. A portion of the compensation for easements will begin as soon as landowners sign an easement agreement, and all remaining payments per the terms of the easement agreement will be paid before construction commences on an easement.
How will the market value be determined?
  • Prior to formal negotiations with a landowner, a market study is performed within each county along the proposed right-of-way by a certified independent appraiser to determine the average fair market value of different land use types within each county. These average fair market values and specific characteristics of each parcel are reviewed to determine the fair market value for each easement along the proposed right-of-way and to determine whether an appraisal is required under the Uniform Act. If an appraisal is required under the Uniform Act, a qualified real estate appraiser employs standard appraisal practices to determine the fair market value of the easement. The appraiser evaluates the characteristics of the property and easement rights being acquired and examines available market data of comparable, recent sales in the same geographic area. Each landowner will be notified of such an appraisal and is encouraged to accompany the appraiser during inspection of the property to identify and discuss any features of the property that the landowner believes have bearing in the determination of the fair market value of the easement.

Will Clean Line compensate for crop damage or soil compaction during construction?
  • Clean Line is committed to minimizing impacts of our project on current land use.
  • Clean Line will repair damage to soil resulting from construction and maintenance of the transmission line and will compensate for crop damage that occurs during construction.
Will Clean Line pay for extra herbicide/fuel and lost production due to farming around structures?
  • Clean Line’s total offer will be intended to compensate landowners for any damages incurred as a result of structures placed on their property.
Will the line impact aerial spraying practices?
  • The project team has and will continue to collaborate with owners and operators of local airstrips as well as appropriate state associations to better understand the impacts that a transmission line might have to aerial spraying.
  • In order to minimize impacts to runways, Clean Line has asked for information on private runways during its outreach efforts and has utilized the additional information as criteria in identifying potential routes.  Clean Line would like to know if additional runways can be identified; please submit a comment here to let the routing team know about your runway if you have not already done so.
  • Clean Line will work with landowners concerned about potential interference with aerial application.  To minimize potential interference, potential routes for the Plains & Eastern Clean Line may be identified along existing divisions of land and/or located in parallel to existing aerial obstructions (such as other transmission lines) to the extent practicable.
  • Clean Line plans to supply the applicable state associations with GPS coordinates for the transmission structures in all states the project will traverse.
What will Clean Line pay if trees must be removed?
  • Clean Line will compensate for commercially marketable timber that is taken down as a result of construction and maintenance of the line.
Will even the small trees have to be removed? Can landowners keep the wood?
  • Trees and other vertical vegetation that pose a threat to the safety or reliability of the transmission system will need to be cleared or managed in order to comply with NERC standards for vegetation clearance distances. Landowners will be given the option to keep the felled trees.

Will you be on public land or private land?
  • Right-of-way acquisition for a project of this size in this part of the country may involve both private and public land; however, our project will pass through primarily private easements as most of the land along our potential routes is private.
What if damages occur to fencing or other property during construction or maintenance?
  • Clean Line will either repair or compensate landowners for damages to improvements, such as fences, incurred as a result of the construction or maintenance of the line on their property.
Will homes be located within the easement?
  • No.  In order comply with National Electrical Safety Code requirements and good utility practice, habitable structures may not be located within transmission line easements.
How close can the transmission line be to a home? Can any structure be within your right-of-way?
  • Clean Line’s proposed right-of-way avoids all identified homes.
  • Safety and reliability requirements establish minimum clearance distances between the conductors and any structures. Habitable structures are not allowed within the right-of-way.
  • Clean Line would like to know if you have a home in the current proposed right-of-way; please submit information to your land agent along with a map reflecting your information.

Will the Plains & Eastern Clean Line reduce property values?
  • Every landowner’s property is different, and without knowing all the specifics it is difficult to say definitively  what impact, if any, the proposed transmission line would have on a property. However, the relationship between transmission lines and property values has been the subject of systematic research for nearly 50 years. Clean Line commissioned Tom Priestly to perform a review of this body of research. His review concluded that these studies show that being close to electric transmission lines can have little or no negative long-term effects on residential property values, with average impacts ranging from no effect on value to a decrease in value of up to 10 percent. All that said, landowners will be compensated for 100% of the fee value of the land in which the easement area is located and will receive additional payments if they have structures on their land.



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 across long distances. DC lines can transfer significantly more power with greater efficiency than comparable AC lines.  For more detailed information about DC, please click here.
What is the difference between alternating current and direct current?
  • Historically, the transfer of electricity between regions of the country has been over high-voltage alternating current (AC) transmission lines, which means that both the voltage and the current on these lines move in a wave-like pattern along the lines and continually change direction. In North America, this change in direction occurs 60 times per second (defined as 60 Hertz [Hz]). The electric power transmitted over AC transmission lines is exactly the same as the power we use every day from AC outlets but at a much higher voltage. Over the past 40 years, high voltage direct current (HVDC) transmission lines have been constructed that offer significant electrical, economic, and environmental advantages over AC transmission lines for long distances. DC transmission is especially suited for integrating and transporting power generated by various renewable energy sources. Unlike an AC transmission line, the voltage and current on a DC transmission line are not time varying, meaning they do not change direction as energy is transmitted.

Is DC a new technology?
  • Direct current transmission (DC) 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 North America.
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, and the AC grid across our nation also requires significant expansion.  DC complements the existing AC transmission network and can be an additional source for system reliability.
Why did Clean Line select DC for the Plains & Eastern Clean Line project?
  • Direct current (DC) is the preferred technology for moving large amounts of power over long distances. The use of a 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, smaller footprint than AC lines that carry similar amounts of energy, and the ability to control the power flow.

Will DC strengthen the grid?
  • DC lines do in fact strengthen the grid.  DC lines are completely controllable, unlike AC, where the power flows on the path of least resistance.  Clean Line has been working with the regional transmission operators, the Southwest Power Pool (SPP), Mid-Continent Independent System Operator (MISO) and Tennessee Valley Authority (TVA), to ensure that the project can be integrated into the system without violating any reliability criteria.
What is the voltage rating of this line?
  • The Plains & Eastern Clean Line is a +/- 600 kilovolt high voltage direct current transmission line.
Can you place the line underground?
  • Underground cable systems for power transmission are very complex and depend upon a number of factors in order to operate efficiently and reliably.  To date, there have been no underground cable systems designed or installed at the proposed voltage and power ratings that will be utilized by the Plains & Eastern Clean Line, nor over the proposed distances. The highest achieved cable ratings for HVDC, thus far, are ±500 kV at about 2000 MW and utilized in very specific applications and relatively short distances compared to the Plains & Eastern Clean Line. 
  • Undergrounding the Plains & Eastern Clean Line would be technically and economically infeasible.
What is a converter station?
  • Converter stations are required for each of Clean Line’s projects to convert power from AC to DC or vice a versa. The DC converter station in the wind resource area is used to convert the incoming AC power generated by the wind farms into DC power. The delivery converter station on the other end converts DC power into AC power to be delivered to customers through the existing AC grid. The delivery converter station in Arkansas can both deliver into and pick-up energy directly from the state.

What is the life span of the converter station and the transmission line?
  • While the design life of a DC converter station is typically 30 years, operational experience of existing DC lines reveals that they are operated safely and reliably well beyond this standard time frame.  For example, the Pacific DC Intertie, which connects wind and hydro resources of the Pacific Northwest to Los Angeles, has been functioning successfully (with the appropriate upgrades and maintenance) since 1970 and is expected to operate for many decades into the future.
How many converter stations will there be?
  • The project will include three converter stations: one at each endpoint and an intermediate delivery converter station in Pope County, Arkansas.

What equipment does the converter station entail?
  • Each converter station is equipped with the following components:
    • DC switchyard:  DC lines enter the converter station through the DC switchyard.
    • Converter buildings: These buildings contain the valve halls, the control room, mechanical and electrical operations and additional operational and maintenance facilities.
    • Valve halls: This is the heart of the conversion process.  Each valve hall contains numerous valves (“electronic switches”) that switch off and on to convert DC to AC and vice versa.
    • Synchronous condensers or STATCOMs: The function of the condenser or STATCOMs, if needed, is to assist in control of the AC voltage and to enhance the performance of the conversion process.
    • Converter transformers: Specialized converter transformers which step the AC voltage up to 600 kV and provide some cancellation of harmonics generated in the conversion process.
    • AC switchyard:  This is where the power will enter or leave the HVDC Converter Station and enter into the AC network which will then disperse the energy into the power grid and ultimately to consumers.   This part of the station looks like a typical AC substation with the addition of various filter banks.
How large will the converter station site be?
  • The endpoint converter stations and associated alternating current (AC) switchyards near Guymon, Oklahoma and Millington, Tennessee are expected to each require on 45 – 70 acres. The intermediate delivery converter station and associated AC switchyard near Pope County, Arkansas is expected to require 20 – 45 acres.
Is there noise associated with the converter station?
  • Noise from the converter station is not typically an issue.
  • Noise is typically limited to 55 decibels (dB) or below at the edge of the perimeter fence of the converter station and the sound will dissipate as you get farther away.  An example of the 55dB noise level is a “quiet suburb conversation at home” – quieter than a central air conditioner unit from 100 ft. away.
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 Plains & Eastern 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, and will not flow through the earth below.


What type of structures will the transmission line use?
  • There are many factors that must be considered when determining the structures to be used for the transmission line, including terrain requirements, land-use constraints (for instance avoiding interference with center pivot irrigation systems), and cost (steel prices can vary widely over time).
  • Several structure types are under engineering review.  Clean Line is currently analyzing a variety of structures including steel monopole and steel lattice structures.
  • For a simulation of what the structures might look like, please click here.  
How tall will the structures be?
  • We anticipate the majority of the structures will typically be between 110 and 150 feet tall. However, the exact height of the structure depends on several variables, including: engineering requirements, topography, structure type, and span length. Generally, the taller the structures, the greater the span between structures; and, the shorter the structures, the shorter the span between structures. This means if structures are at the taller end of the 110 to 150 foot range; there typically will be fewer of them. Instances when the structures could exceed 150 feet in height include river crossings or terrain that would require longer span length.

How large will the foundation footprints be?
  • The typical foundation footprints will be between six feet and eight feet in diameter for tubular monopole or lattice mast type structures with a single pier foundation.  Typical lattice structures with four “legs” and four foundations will have a footprint of about 27 feet x 27 feet.  Typical guyed lattice mast structures will have one foundation with a footprint of six to eight feet in diameter.  The four guy wires to aid in the support of these lighter structures will extend outward to a distance of 80 to 105 feet from the center of foundation.  In rare instances, terrain could require the guy wires to exceed 105 feet from the center. Guyed lattice mast structures will only be placed in areas where they are compatible with current land use. We will not use this type of structure where there are row crops or similar agricultural activities.
What is the minimum clearance below your transmission line?
  • Minimum clearances are designated by the National Electrical Safety Code (NESC) and vary depending on several factors, such as vehicular traffic or pedestrian usage.  The design of our transmission line must meet or exceed NESC requirements.
  • For a line of this type and voltage, minimum ground clearances according to NESC is 31 feet.  Clean Line intends to use an additional 3 foot buffer for a total clearance of 34 feet at the lowest sag in the line.  This is an absolute minimum at the lowest point on the conductor, at lowest possible sag.  The majority of the time, the actual clearance will be higher.
What is the span length between structures?
  • Clean Line anticipates that there will be between 3 and 6 structures per mile, with span lengths from 1,000 feet to 1,600 feet between structures.  As with structure height, there are several variables that factor into the exact span between structures, such as structure type, soil conditions, and topography.
  • These ranges will encompass the large majority of span lengths along the line, but there may be longer or shorter spans lengths due to engineering and environmental considerations, such as river crossings.

Electronic Interference

Are there any impacts to radio signal? If so, what are they?
  • FM radio receivers typically do not pick up interference from transmission lines.  If there is AM radio frequency interference, it typically occurs immediately under a transmission line and dissipates rapidly away from the line.
Are there any impacts to television signal? If so, what are they?
  • Digital television signals are not impacted; therefore, television interference is highly unlikely.
Will the line interfere with GPS signals?
  • GPS units associated with farm equipment will operate with their traditional degree of accuracy near and under high voltage transmission lines.
  • Information about television and radio reception, cell phones, wireless internet, and global positioning system (GPS) satellite receivers is discussed in the section on electric fields in a whitepaper that Clean Line commissioned to summarize research conducted on these topics.  The section on magnetic fields discusses standards throughout the world and research regarding potential effects on implanted medical devices. At the end of the whitepaper is bibliographical information for all the studies referenced or summarized.  To view that study, please click here.
Will the transmission line impact or induce currents on natural gas pipelines?
  • Since the transmission line is DC, there is no varying magnetic field that can induce a current into the adjacent pipeline structures.
  • Under normal operations a bi-pole HVDC 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.  This return path can be another set of wires on the transmission structure (sometimes referred to as a dedicated metallic return or dedicated metallic neutral).  At this time, Clean Line intends to utilize a dedicated metallic return. 
Is there sound associated with the line? How much and what will it sound like?
  • At the edge of the right-of-way, the sound associated with the line should be in the same range as a whisper.  Audible noise is produced by corona on transmission line conductors. Corona is an electric discharge from the conductor caused by ionization of the air. This sizzling or crackling sound is called random noise.  Random noise results from a multitude of small snapping sounds at corona points on the conductor.

Health and Safety

What is EMF?
  • EMF stands for electric and magnetic fields. 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 electrons. EMFs are naturally present in the environment and are present wherever electricity is used, for example a toaster, cell phone, a battery operated device, a lamp, a 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.

What health effects are associated with electromagnetic fields (EMF)?
  • There are no known long-term health impacts from the EMF associated with a transmission line. The magnetic field of a DC line is similar in nature to the natural magnetic field of the Earth (the same field that allows a compass to work), and the strength of the magnetic field while standing beneath the conductors is comparable to the strength of the Earth’s field.  The static electric field of a DC line when standing beneath the conductors is ten times weaker than the static electric charge you may get from walking across a carpet on a dry winter day.
  • For more information on electromagnetic fields and HVDC transmission, please click here to download a fact sheet.

What is stray voltage?
  • The term “stray voltage” can refer to several phenomena involving the creation of an unintended electric potential difference (voltage) between two conductive surfaces. In areas where power lines traverse agricultural land, the term often refers to the development of a potential difference between the grounded neutral conductor of a power line (a wire that usually carries minimal current) and the ground to which it is connected, causing current to flow on the grounded neutral. This current, in turn, can develop a potential difference with nearby conductive material present in agricultural operations.
  • Under normal operation and with proper safety measures in effect, stray voltage remains below levels that affect the health or behavior of persons or animals. 
  • There is also no stray voltage from a DC line.  DC transmission lines do not induce voltages on neighboring vehicles, structures, fences, or other conductive materials or nearby surfaces.
Are there any studies that would suggest harm to people or animals either short-term or long-term from the transmission line?
  • Several studies have assessed the impacts on agricultural operations of stray voltage, along with electric and magnetic fields, corona and air ions. According to an epidemiological study of 500 herds of Holstein dairy  cattle, herd health, measured using multiple indicators, did not differ between periods before and after a nearby +/- 400 kV direct current line was energized. These results did not vary based on the herd’s distance from the high voltage direct current power line. Another study conducted by Oregon State University titled “Joint HVDC Agricultural Study” determined that no differences were found between cattle and crops raised under+/-500 kV direct current lines and those raised away from the lines. A report by the Western Interstate Commission for Higher Education also determined that a +/- 400 kV direct current transmission line did not affect crops, vegetation, or nearby wildlife, nor were the electric and magnetic fields from the line felt by persons walking in the right-of-way.

Who did your health testing to determine there are no known health effects on humans or animals?
  • Clean Line worked with Exponent to review existing independent studies and compile materials pertaining to health effects from direct current transmission lines for Clean Line’s use.  Exponent is an engineering and scientific consulting firm providing solutions to complex problems. Exponent’s multidisciplinary organization of scientists, physicians, engineers, and business consultants brings together more than 90 technical disciplines to address complicated issues facing industry and government today. The firm has been best known for analyzing accidents and failures to determine their causes, but in recent years it has become more active in assisting clients with human health, environmental and engineering issues associated with new products to help prevent problems in the future. 
  • Potential health impacts, if any, from the Plains & Eastern Clean Line will be discussed in the Environmental Impact Statement currently being prepared by the U.S. Department of Energy. This report will be available to the public.
Is it safe to park vehicles underneath the line? Can a vehicle shock you?
  • It is safe to park beneath the line, though if the vehicle is strongly insulated from the ground, you could get a static electric shock from touching the vehicle in the same way that shuffling your feet on a carpet could give you a static electric shock when touching a doorknob due to an accumulation of charge.
Can my livestock graze under or around the transmission line?
  • Yes.  Extensive studies indicate that exposure to transmission lines pose no harmful effect to farm animals.
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. Clean Line’s Avian Program establishes a framework for reducing risks to birds and describes Clean Line’s policy to develop and implement Avian Protection Plans.  To read and download Clean Line Energy Partners’ Avian Program, please click here.


How many jobs will the Plains & Eastern Clean Line create?
  • The Plains & Eastern Clean Line will bring substantial economic benefits throughout the project region. It is estimated that the Plains & Eastern Clean Line will result in thousands of direct construction jobs building the transmission line, associated facilities, and new wind farms and hundreds of permanent jobs maintaining and operating the transmission line and the associated wind farms. Additionally, businesses will see increased demand for their products and services, 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.

Does the Plains & Eastern Clean Line project require or expect federal subsidies?
  • No.  There are currently no federal subsidies for transmission lines and Clean Line has not sought any.
Who will pay for the Plains & Eastern Clean Line?
  • The development and construction of the Plains & Eastern Clean Line is estimated to cost roughly $2 billion. Clean Line will finance the transmission lines and will sell transmission capacity to wind energy developers that wish to transmit their energy to market, and to utilities that choose to buy the low-cost clean energy delivered by the line.

What if Clean Line cannot find customers for the energy?
  • If a large majority of the capacity is not sold, then the project will not be built. We would have in place the entirety of the construction financing prior to commencing construction.

Is there a demonstrated need for transmission lines like these?
  • Numerous studies by the U.S. Department of Energy (DOE) and other government and nongovernmental organizations have demonstrated a need for HVDC transmission lines.  Clean Line will still have to sell the capacity on its transmission lines before they are built, and if the capacity is sold to customers then the need is assured.
Will Clean Line have customers between the end points?
  • Clean Line is working to secure customers in Arkansas, Tennessee, and throughout the Mid-South and Southeastern United States. 

Construction / Operation / Maintenance

When will Plains & Eastern Clean Line begin construction?
  • The Plains & Eastern Clean Line is expected to begin delivering electricity as early as 2020.
What local business opportunities might be associated with construction?
  • We will need a wide variety of services, materials, and equipment to construct the transmission line like surveying, right-of-way clearing, and pouring concrete.
  • While construction may not begin for a number of years, we want to learn about qualified local businesses that could provide products and services for the Plains & Eastern Clean Line.  If you would like to stay informed of our progress and be notified when we seek sub-contractors, please submit your business information online here.
During construction will there be oversized or overweight vehicles/equipment on roads?
  • Yes. The construction of a transmission line of this size generally requires the use of oversized vehicles and machinery. Clean Line recognizes the risks associated with heavy traffic on county and local roads. We will minimize the impact of these vehicles to existing road networks and will repair any damage caused by construction activities. Clean Line will work with the state departments of transportation and county officials and engineers to plan road use during construction.

What portion of the right-of-way will need to be cleared?
  • The amount of right-of-way that will need to remain cleared of tall-growing vegetation for the operation of the line will depend on the types and prevalence of woody, vertical vegetation that grows within the transmission line right-of-way, its potential height at maturity, and conductor clearances relative to potential vegetation height at maturity. Typically, agricultural crops (with the exception of tree crops), pasture lands, and grasslands will not need to be cleared for the operation of the line; however, trees and other vertical vegetation that pose a risk to the safety or reliability of the transmission system, per NERC Reliability Standard FAC 003-3 (or future versions), will need to be routinely maintained based on potential safety and reliability concerns.
How will Clean Line address impacts of construction to farmland?
  • We will work to prevent and/or mitigate agricultural impacts associated with the construction process. Reclamation activities that may be implemented on impacted areas include, soil removal, soil de-compaction, soil fertilization, erosion prevention, and repair of damaged soil.

  • Clean Line will consult with landowners and/or tenants to identify the location and boundaries of agriculture or conservation reserve lands and to understand the criteria for maintaining the integrity of these committed  lands. Additionally, Clean Line will work with landowners and/or tenants to identify specialty agricultural crops or lands (e.g., certified organic crops or products that require special practices, techniques, or standards) that may require protection during construction, operation, or maintenance. Clean Line will avoid and/or minimize impacts that could jeopardize standards or certifications that support specialty croplands or farms.

What is a Multi-Use Construction Yard or Lay-Down Yard?
  • Multi-use construction yards, sometimes called lay-down yards, are typically located off the right-of-way (ROW) on a parcel specifically negotiated for storing equipment, components and other materials. Construction work is coordinated from these areas. Multi-use construction yards will be nearby but not necessarily adjacent to the ROW. Clean Line will locate multi-use construction yards outside the ROW and typically at intervals of approximately 25 miles. Additionally, they will be located within approximately 10 miles of the ROW or Project facility. Typical multi-use construction yards will be approximately 25 acres in size, fenced and access-controlled.
  • Clean Line will negotiate with landowners interested in hosting such facilities.

  • Staging areas are typically located within the ROW and are used as miniature multi-use construction yards.The components for a few structures may be arranged in a staging area immediately before they are assembled. Staging areas will not be common, due to the extra work involved in the off-load and on-load of structure parts (double-handling). Construction crews will naturally minimize handling time and costs, usually by transporting components directly to each structure location.

  • In some instances, weather, topography, other environmental factors, or construction activities such as pulling and tensioning of the conductors may require activity outside the staging areas or ROW. These specific instances will be discussed with landowners in advance and will only take place where such use is permitted.

  • A staging area is displayed in the construction simulation video on the Plains & Eastern Clean Line website in order to demonstrate what this area may look like when used.

Are any access roads going to be built for the project?
  • There will be a mixture of temporary and permanent roads—though permanent roads in cropland would be highly unusual. Clean Line will negotiate the nature of access roads with landowners, and the landowners will be compensated accordingly.

  • Roads not otherwise needed for maintenance and operations will be reclaimed to preconstruction conditions. Reclamation practices may include decompacting, recontouring, and re-seeding. Roads needed for maintenance and operations will be retained.

  • Construction crews will make an effort to access the right-of-way easement from public roads that intersect or are adjacent to the right-of-way. Once an access road is established, construction will follow the right-of- way to the next access road location, which preferably will be located at the next public road crossing. In some instances, depending on topography or other environmental conditions, off-right-of-way access may be needed to facilitate construction or maintenance of the line.

Who will operate the Plains & Eastern Clean Line?
  • Like many other transmission lines, the Plains & Eastern Clean Line will be controlled by one of the regional transmission organizations (RTO).  RTOs are responsible for planning and coordinating the transfer of energy over large multi-state areas.  An RTO controls and monitors an electric transmission grid that is larger and uses higher voltages than a typical single power company’s distribution grid. 
Who will operate the converter station?
  • Typically, converter stations of this sort are operated remotely by highly skilled operators in cooperation with the Regional Transmission Organization (RTO) to ensure reliability and transparency in administration of the tariff.
  • Operation staffing will consist of Clean Line employees or other contractors with appropriate technical expertise and certification by the North American Reliability Corporation (NERC) as system operators.
What is the maintenance plan for the line? Will you ever use helicopters?
  • There will be a regular maintenance plan for the line.  The plan will involve visual inspections, and this typically involves a helicopter.  This typically takes place a couple of times a year.  Repairs will typically take place from land-based crew and trucks. 
  • Any emergency repairs would need to happen immediately. Landowners will be notified prior to any scheduled maintenance work conducted on their property.
How will you maintain vegetation in the right-of-way? Will you use chemical herbicides?
  • Clean Line will minimize clearing vegetation within the ROW, consistent with a Transmission Vegetation Management Plan filed with NERC, and applicable federal, state, and local regulations. Clean Line will work with landowners to plan vegetation maintenance in ways that minimizes conflicts with existing land uses, including local farming practices.
  • Prior to the beginning of operations, Clean Line will develop a Transmission Vegetation Management Plan which will define site-specific standards, measurable metrics, and vegetation management objectives; and prescribe controls or treatment options (e.g., mechanical, biological, or chemical) to achieve defined objectives that support the goals of an integrated vegetation management framework.

  • Additionally, on organic farms, no herbicides, pesticides, fertilizers, or seed would be applied unless approved by the landowner.