Community & Environmental Defense Services (CEDS) is assisting community groups, nonprofit organizations, and individual home-property owners throughout the United States with concerns regarding existing and proposed transmission lines. While transmission lines are essential to maintaining reliable electric service and increasing green energy from wind and solar, in some instances major new lines are proposed because of the tremendous profits they can produce without providing benefits justifying the adverse effects.

This website summarizes the key issues associated with major transmission lines along with strategies for defeating poorly conceived projects. If you have any questions, including how CEDS can assist you with transmission-line related concerns, contact us at 410-654-3021 or Help@ceds.org.

Transmission Line Electromagnetic Fields (EMF) & Health

It is unclear what effect power-transmission line electromagnetic fields (EMF) have on human health. Here are recent, verbatim summaries of scientific research from credible sources.

National Cancer Institute: “Although a study in 1979 pointed to a possible association between living near electric power lines and childhood leukemia
(16), more recent studies have had mixed findings (17– 25). Most of these studies did not find an association or found one only for those children who lived in homes with very high levels of magnetic fields, which are present in few residences. Several studies have analyzed the combined data from multiple studies of power line exposure and childhood leukemia:

• A pooled analysis of nine studies reported a twofold increase in risk of childhood leukemia among children with exposures of 0.4 µTor higher. Less
  than 1% of the children in the studies experienced this level of exposure (26).
• A meta-analysis of 15 studies observed a 1.7-fold increase in childhood leukemia among children with exposures of 0.3 µTor higher. A little more
  than 3% of children in the studies experienced this level of exposure (27).
• More recently, a pooled analysis of seven studies published after 2000 reported a 1.4-fold increase in childhood leukemia among children with
  exposures of 0.3 µTor higher. However, less than one half of 1 of the children in the studies experienced this level of exposure (28).

For the two pooled studies and the meta-analysis, the number of highly exposed children was too small to provide stable estimates of the dose-response
relationship. This means that the findings could be interpreted to reflect linear increases in risk, a threshold effect at 0.3 or 0.4 µT, or no significant increase.

The interpretation of the finding of increased childhood leukemia risk among children with the highest exposures (at least 0.3 µT) is unclear.”

USEPA: “Electric and magnetic fields, also known as electromagnetic fields (EMF), consist of waves of electric and magnetic energy moving together. These energy fields surround us all the time. Scientific studies have not clearly shown whether exposure to EMF increases cancer risk. A few studies have connected EMF and health effects, but they have not been able to be repeated. This means that they are inconclusive.”

How Do Transmission Lines Affect Property Value

A 2018 study, The Pricing of Power Lines, examined the effect of proximity to High voltage Transmission Lines on the value of 5,455 vacant lots sold in Pickens County, SC. The researchers concluded that the value of lots adjacent to a power line sold for 45% lower and an 18% reduced values for lots within 1,000-feet.

A study published in 2002, Power Lines, Visual Encumbrance and House Values, found that homes within view of a power line sell for 5% to 20% less.

In a 2010 study, The Effects of Electric Transmission Lines on Property Values: A Literature Review, the authors concluded:

“The studies reviewed, while having some inconsistencies in their detailed results, generally pointed to small or no effects on sales price due to the presence of electric transmission lines. Some studies found an effect but this effect generally dissipated with time and distance. The effects that were found ranged from approximately 2% to 9%. Most studies found no effect and in some cases a premium was observed. This was attributed to the additional open area usually behind the residence created by the transmission line easement.”

Given that the studies cited above and other research documents that properties within view of a transmission up to 1,000 feet away may lose value, the potential property value impact zone likely extends no further than 1500-feet. Of course, if the pylons, towers, poles and circuits wires are not visible then the impact zone would be less than 1500 feet.

Transmission Line Visual Impacts

The towers (pylons, poles) supporting a transmission line may be 200-feet tall or more. Transmission line right-of-way may measure 50- to 600-feet in width and is frequently cleared of all vegetation except grass or other low-growing plants. Depending upon topography, forests, and other factors a transmission line may be visible from a distance of three miles or more. As noted above though, adverse effects on property value likely do not extend beyond 1500-feet from a transmission line or a lesser distance where it is no longer visible.

Those who study the effect of new transmission lines on views commonly begin their analysis three miles out. When passing through forest, a transmission line corridor appear as an ugly gash across the landscape. Such a scene detracts from the beauty of an otherwise natural view. When located near a community, transmission lines can lend an industrial feel to what otherwise tranquil residential neighborhood.

Following are two studies showing that a proliferation of transmission lines can harm a regional tourism-based economy where visitors are attracted by the scenic, natural or historic features of an area.

In a 2021 study, Analysis of the impact of high voltage power lines on the value of properties in environments of high ecological value and rural tourism: the case of the Lecrín Valley (Granada – Spain), the researchers reached the following conclusions:

“Through a comparative methodology, the projected losses to property values in the municipalities of the area and the economic and social implications caused by the visual impact of the HVPL [High Voltage Power Lines] are quantified. The conclusions point out that the infrastructure [High Voltage Power Lines] would rupture of the regional balance while generating precariousness, loss of wealth in economic and patrimonial terms for the region as a whole.”

“Therefore, according to the studies analysed in Sections 2 and 3, for habitual residences or second homes, average values of depreciation of 45%–50% would be applicable considering the special beauty of the zone. Such values would increase, as established by previous studies, in consonance with increased proximity to the pylons and can reach percentages close to 70%. That is why the two variables used to categorize the impact of the passage of the HVPL on the real estate value are the proximity to the pylons and visibility, as shown by the studies. The impact, however, is greater in a scenic area of great beauty where there are constant leisure and work displacements of both the resident and tourist population.”

In the 2017 study When tourists meet transmission lines: The effects of electric transmission lines on tourism in Iceland, the researchers concluded:

“Although transmission lines are necessary to carry renewable energy, they are often highly visible and frequently meet strong public opposition. This is especially true in areas with a high degree of perceived aesthetic naturalness, which are often valued landscapes for nature-based tourism. Due to tourism’s economic importance, and the growing necessity for a stronger transmission system, it is imperative to identify tourists’ opinions on transmission lines in natural areas. Attitudes were analysed by employing a questionnaire at seven locations where power plants are proposed. Results demonstrate that tourists are generally negative towards transmission lines, especially in the Highlands and consider them one of the least desirable infrastructures.”

The following graph from the Iceland study lists features which scenic area visitors find most to least acceptable, with transmission lines near the bottom.

For further detail options for assessing visual impacts and options for screening undesirable features from view, visit the CEDS Scenic Views & Land Development: Preserving Views from Your home & Other Favorite Places webpage: https://ceds.org/view/

Options for Gaining Transmission Line Benefits Without Impacts

In general, it is far easier to win changes that resolve impacts compared to stopping a  proposed transmission line project. In addition to winning good visual buffering with trees, earth berms, etc., impact resolving changes can include placing the a portion or all of a line underground, co-locating it along a highway, rail line or existing transmission line, or bumping the alignment away from sensitive areas.

Undergrounding: Burying Transmission Lines

Placing new transmission lines underground resolves much of the visual impact and greatly reduces electromagnetic field strength. Those wishing to construct new transmission lines will frequently argue that burying a line is substantially more expensive compared to overhead installation. However, when all the costs of an overhead line are summed for the 100-year transmission line lifespan, burial is a bargain, at least for those who must live with the project. These “all the costs” include: property value loss, decreased farm and forest productivity, health costs, tourism income losses, visual impacts, environmental damage, etc.

In their 2012 study Cost and reliability comparisons of underground and overhead power lines, the researchers wrote:

“This paper outlines the benefits of undergrounding power lines. We present research that reveals the reliability and operation and maintenance (O&M) impacts of electric underground lines relative to overhead lines. This research uses a comprehensive dataset from 163 US electric utilities. Holding the effects of other important operating variables constant, our research indicates that undergrounding reduces O&M cost and enhances reliability by reducing power outage durations.”

“In general, underground lines greatly diminish the need for right-of-way clearing expenses. As mentioned above, underground lines also lower the number of interruptions due to vegetation, animals, and weather.”

“Two main considerations beyond costs and reliability are increased aesthetic value and improved safety. Studies have shown that in an urban context, homeowners value the aesthetic improvements of underground lines, and this can increase property values.”

In their 2019 study, Underground power lines can be the least cost option when study biases are corrected, published in The Electricity Journal, the coauthors wrote:

“However, many studies of U.S. electric utilities have concluded that a broad undergrounding mandate would be too expensive and undergrounding can only be justified when factoring customers’ willingness to pay more for underground lines. We show that misleading national comparisons and improperly conducted U.S. studies have led to false conclusions about the economic efficiency of undergrounding power lines. Once data are standardized and properly disaggregated, the case for undergrounding improves significantly.”

In a 2022, Energywire article Are highway rights of way an answer to power siting dilemma?, regarding a study of the feasibility of placing transmission lines underground along Minnesota highways it was noted:

“The study also said underground HVDC transmission can be built at a cost comparable, on a capacity basis, to much of the 345-kilovolt alternating current (AC) transmission that has been built across the country. It’s a view not shared universally in the transmission industry, and cost is often cited as an obstacle to burying high-voltage power lines.”

The cost difference does not appear as great for High Voltage Direct Current (HVDC) lines. An HVDC circuit is buried in a trench 1.5-feet in width with a separation distance of 15- to 30-feet between circuits. Junction boxes are placed every 1,000- to 2,000-feet to join sections of HVDC cable.

In summary, the research cited above indicates that placing new transmission lines underground should always be given priority when:

• A line is proposed in a suburban or urban area where multiple homes would be within view of an overhead line,
• In the vicinity of rural towns or other home clusters,
• When an above ground line could be seen from multiple existing or future homes within the 1500-foot potential residential property value impact zone referenced above, or
• The transmission line would detract from scenic or historic features due to the industrial feel they impart to an area.

Co-Locating Transmission Lines

There is a growing trend towards locating new transmission lines along highways, rail lines, and existing transmission right-of-ways. In the 2022, Energywire article cited in the preceding section of this webpage, Are highway rights of way an answer to power siting dilemma?, the following appeared:

“Could a key to unlocking a cleaner, more durable power grid and furthering the adoption of electric vehicles be found in vacant strips of land alongside highways and interstates? The answer may be yes, and it’s a concept that’s gaining momentum across the country, according to a feasibility study done for the Minnesota Department of Transportation.”

Co-location options for existing transmission line corridors include:

• Stringing new circuits (wires-cables) on existing transmission line pylons (towers-poles) if space is available,
• Placing a new transmission line underground within the existing right-of-way, or
• Constructing a new line adjacent to the existing right-of-way.

Bumping A Proposed Transmission Line Route

CEDS has had considerable success in negotiating project changes that resolve our clients concerns while allowing applicants to achieve their goals. We call these Equitable Solutions.

Following is a relevant example.

As shown in the aerial below, CEDS assisted Pennsylvania residents in convincing a company that had proposed a new transmission line to change the alignment so it would not cut through a farm that had been in their family for generations.

Defeating Bad Transmission Line Projects

When CEDS first became involved in these cases we intensively researched how citizens fared in transmission line battles throughout the USA. This research showed a pattern we had seen with numerous other issues:

Citizens generally lost when they fought with just lawyers and experts, but the probability of success tripled when legal action was coupled with an aggressive political strategy.

Political action makes success far more likely because:

• publicity is generated well beyond that normally resulting from a purely legal strategy;
• decision-makers are more inclined to decide technical-legal questions in favor of citizens, particularly on close-calls;
• it enhances fund-raising and volunteer recruitment;
• it increases the likelihood legislative bodies will change laws in ways that resolve citizen concerns; and
• when done well, political action puts in place elected officials and advocacy groups which discourage future proposals involving poorly-planned projects.

Combining aggressive political action with Smart Legal Strategies – another CEDS innovation – further increases the probability of success. We call the combined approach Politically Oriented Advocacy. This approach dramatically increases the likelihood citizens will win transmission line cases. Consider the following example:

The Mid-Atlantic Power Pathway (MAPP) was a 500 kilovolt (kV) backbone line originally supposed to run 230 miles from Virginia, through Maryland, Delaware, ending in New Jersey.

When CEDS began assisting citizens with MAPP in late 2008, State officials were all of the same opinion – the transmission line was urgently needed to keep the lights on. We drafted an Initial Strategy Analysis setting forth options for ensuring MAPP would not harm nearby residents. A principle component of the analysis was an aggressive political organizing strategy along with the technical analysis required to support our arguments. The attitude of decision-makers changed dramatically as we implemented the strategy over the ensuing months. In fact, nine State experts eventually registered their opposition to MAPP. These experts were hired by some of the same agencies who’d strongly supported MAPP a year before.

Normally citizens pay upwards of $400,000 for just expert witness testimony in transmission line cases. In MAPP our clients paid but $5,000 or 1% of the total cost of the expert testimony. MAPP was put on hold by the State agencies for four months and the Delaware portion was indefinitely postponed. The company wishing to build MAPP subsequently withdrew their application. MAPP has been dead ever since.

A critical component of Politically Oriented Advocacy is not just opposing something but coming up with a way that makes things better. In the case of transmission lines our better way has taken the form of Comprehensive Energy Planning. Few states have a plan which: 1) shows future energy needs, 2) identifies all reasonable options for meeting those needs, 3) compares those options with respect to cost, reliability, environmental effects, etc., then 4) selects those energy choices which provide the greatest benefits with the fewest negative effects. While not right for every situation, this form of planning does show how citizens can avert an imminent threat and use their political clout to bring about a better future for all.

Keeping Routing Studies Honest

How do you ensure that a transmission line routing siting study fairly analyze all reasonable alignments to identify the best option?

Well, the first step is to understand how an analysis can be manipulated to select the route the applicant prefers vs. that which is best for the rest of us. With this understanding you can determine if the analysis was honest. And if not prove it to decision-makers.

CEDS has created the Siting Game for your use in understanding how siting factors and other analysis variables can be manipulated to make one route appear preferable. The Excel-based Siting Game is posted at: ceds.org/SitingGame.xlxs.

The Game consists of 17 siting factors common to transmission line proposals and begins with values assigned to six candidate routes. When you have a moment try altering the siting factor values to see how easily one of the six candidate routes can be made to appear preferable to the other five.

To learn more about how these analyses work and how to keep them honest, see the Siting Game Excel worksheet labeled How the Siting Game Works.

Need for New Transmission Lines

New transmission lines are usually justified with projections showing that the service area faces an imminent threat of blackouts or other electricity problems. After reviewing the findings from numerous independent evaluations of these projections, it is clear to CEDS that the threat is frequently overstated. Following are a couple of the more common shortcomings.

Flawed Growth Projections

This shortcoming results from reliance upon outdated electricity use projections based on long term trends showing continued growth well into the future. However, growth in electricity use has been slowing since 2002, it was flat in 2007-2008, then declined in 2009 (at least in the Mid-Atlantic states).

This trend is likely to continue due to increased efficiency caused by higher prices as well as state initiatives increasing demand-response and energy conservation. Even as the economy rebounds it is unlikely that growth in electricity use will return to pre-2002 levels.

In the near future utilities will begin supplying customers with advanced (smart) metering equipment which will accelerate conservation and further reduce peak-demand. And it is peak-demand which generally drives the supposed need for new transmission lines.

Flawed Modeling

Criteria for analyzing electric service reliability are established by the North American Electric Reliability Corporation (NERC). Good utility planning practice dictates the use of not only accurate electricity use projections but sound modeling. However, the applicant need analyses we’ve reviewed frequently show several bad planning practices. First, realistic reductions in energy use through demand-response and conservation are not included. Second, proposed increases in generating capacity are not included even though the increase meets NERC criteria for inclusion. Third, projections are based upon highly unreliable extrapolations rather then the required contingency analyses. Fourth, alternatives such as upgrades to existing transmission lines and substations are not thoroughly evaluated then compared to the proposed backbone project.

Transmission Line Basics

As shown in the following illustration, transmission lines convey electricity from locations where it is generated to the substations-transformers where it is then runs via distribution lines to our homes, businesses, etc.

Transmission lines consist of the circuits (wires-cables) that carry electricity. The circuits are mounted on structures called pylons, poles or towers.

Overhead transmission lines are located in a right-of-way 75- to 200-feet or more in width.

You can estimate the voltage of an existing transmission line by counting the number of insulators. For each insulator the voltage will range from 14- to 20-kilovolts (kV). So a 345 kV would have about 18 insulators like that pictured to the right.

Following are some good publications on the basics of electricity and transmission lines.

• Electricity Transmission: A Primer
• What’s Wrong with the Electric Grid?
• NERC Reliability Standards for the Bulk Electric Systems of North America