Big Power Line Project Proposed To Transport Iowa Wind Energy

A Texas energy company wants to build a 500-mile electricity transmission line originating in northwest Iowa that could help double Iowa's wind energy output. It would deliver wind power from Iowa to states east.

Published on: Oct 19, 2011

By Loren Gaylord Flaugh

Editor's note: Loren Flaugh is a freelance writer from Primghar, Iowa. He follows energy issues closely, after a career in the energy industry. For more information about Clean Line Energy and the company's proposed transmission line to transport wind-generated electricity from Iowa to Illinois and states further east, go to www.CleanLineEnergy.com.     

Stalled wind farm expansion in Northwest Iowa could receive a major shove forward, if Houston, Texas, based Clean Line Energy Partners gains regulatory and land owner approval for their proposed Rock Island Clean Line electric transmission project.

Clean Line Energy is focused on developing high voltage direct current (HVDC) transmission lines from regions where the best wind power potential exists. This $1.7 billion dollar project may spur on an additional $7 billion of wind farm construction in a region that includes Minnesota, South Dakota and Nebraska.  The 3,500 megawatt (MW), HVDC power line will originate in either O'Brien or Cherokee County. With a terminus at a DC to AC converter station near Chicago, the line will deliver three-phase AC power to utilities in Illinois and areas further east. The 500-mile, 600,000 volt (kV), HVDC line could power 1.4 million homes.

Ambitious best describes Clean Line's total initiative. Three other HVDC lines will exploit and export the wind energy potential of the American High Plains and ship electricity to demand centers like St. Louis, Memphis and the Southwest. 

Meetings have been held this year seeking landowner input

Director of development Hans Detweiler and other project members hosted informational meetings across Iowa and Illinois. The purpose is to seek public comment, discuss the need for power transmission, define the Rock Island Clean Line Project and to explain their transmission line routing process. About 60 to 80 landowners and other interested people attended a meeting at Paullina on June 2, 2011. O'Brien County economic development director Kiana Johnson said, "Some landowners were specifically asked to attend this open house."

Routing any new power line remains a prime concern for landowners, regulating authorities or people wanting consideration given for habitat areas. Clean Line has defined a "Study Corridor", a 3 to 10 mile wide strip starting in Northwest Iowa, traverses the state and ends near Chicago. Within that sliver of land a route will be finalized and sent to the Iowa Utilities Board and the Illinois Commerce Commission.

Many factors will go into making this final determination. Some include: landowner feedback, land usage, conservation agency input, water resources, engineering concerns and clearances from residences.

Right-of-way and easement issues of concern to farmers, landowners

Vice President, transmission and technical services, Wayne Galli, explained via email Clean Line's right-of-way and easement policies. Galli said, "During construction, there may be requirements for wider material lay down areas and constructions easements along the right-of-way.  Our typical easement will be around 200 feet wide and that will be the final easement width."

Because this is a HVDC line, as opposed to an HVAC line, the structures supporting the power cable are significantly smaller.  For example, a 3-cable 500 (kV) AC support tower is 1.5 times larger than a 600 kV DC tower.  This means that construction costs for an HVDC power line is 30% less than a HVAC line.

Though a galvanized steel lattice tower could be used, Galli indicated that a single monopole would also support the aluminum power cables.

"For typical tangent tubular steel poles, the height will range from around 120' to 160' and weigh upwards of 50,000 pounds. The base dimensions will be between 4' to 6' in diameter with a concrete foundation adding another 6" to 12".  Farmers should be able to farm right up to the edge of any foundation," said Galli. He said each landowner could determine which support structure is used, and adds "With lattice structures, typical spans can reach or exceed 1500' between structures, whereas with monopoles the structures are typically 900' to 1100' apart."  A greater distance between poles means that fewer structures will be required.

What about payments to landowners for construction right-of-way?

Though early, Clean Line communications director Sarah Bray addressed the issue of compensation payments to landowners for granting construction right-of-way. She said "It's still too early. We can begin to discuss compensation after we host informational meetings with Iowa Utilities Board staff, likely later this year."

Bray then moved on to discuss the issue of reclaiming the right-of-way once construction is completed.

"We take farming operations and other existing land use very seriously and are committed to minimizing the impacts of our project on current land use.  We've started discussions with the Iowa Department of Ag on how to minimize impacts to land use and we plan to enter into an Agriculture Impact Mitigation Agreement. This Agreement would govern our routing, engineering and construction practices to ensure landowner concerns are taken into consideration."

Bray continued, "Our construction contractors will be responsible for returning the right-of-way to farmable condition and the contractor will abide by this same agreement.  We are open to considering many ideas on how we can minimize the impacts that construction has on farming operations."

Building this transmission line would create new property tax revenue

While the temporary jobs (5,000) and permanent jobs (500) that this project could yield are important, others tout the property tax windfall it will bring to many localities.  O'Brien County Assessor Lowell Dykstra looked into the property tax potential based on 2011 levies and rates.  Dykstra said these rates could easily change by 2016, when the HVDC line is scheduled to begin operations.

Because Clean Line's proposed HVDC transmission line is directly related to wind energy conversion, the project will receive a graduated, seven-year tax abatement according to the O'Brien County Wind Energy Ordinance. With no property tax payment due the first year, the rate increases incrementally by 5% each year to 30% at the 7th year.

Based on a $250,000,000 estimated cost, Clean Line's converter station will have a taxable value of $75,000,000. At 10% tax rate the 3rd year, the property tax payment is $625,000. After the 7th year the property tax payment soars to $1,875,000.  Half that figure, or $937,500, will go to school districts, depending on the exact location of the site.

With a .67631 per thousand dollar levy for Northwest Iowa Community College, NCC would receive $50,723 after the 7th year. Because Center Township has a .43594 levy, Center Township benefits to the tune of $32,695 after the 7th year.  

Commenting on the potential impact, Dykstra said, "It will be a good thing.  We've been at it now for 10 years, but I don't want to get my hopes up. It will be good for the tax base."

Proposed Clean Line Energy project: Are local people for or against it?

Primghar Savings Bank vice president Rodd Holtkamp says, "If all this comes to be, there isn't a citizen in the county that won't benefit from it." Regarding the Clean Line representatives he met, Holtkamp says, "They're like a breath of fresh air.  They're very sincere, very open about their project and they go out of their way to explain everything.  They seem like really good people."

Dr. Alethea Stubbe, President Northwest Iowa Community College said, "We are excited about the potential of this project." She says, "This project will provide enormous economic impact with the creation of line construction, manufacturing and technical jobs, and the environmental benefits for the northwest Iowa region.  Northwest Iowa Community College has promoted clean energy for many years most recently working with green jobs training through our RECs, MidAmerican Energy and others. NCC has anticipated this expansion with a new high voltage Substation Technician program beginning Fall 2011 to meet the growing demand in Iowa by training additional substation technicians—the first in the state to do so. This project will also create opportunities to expand the curriculum of our on-of-a-kind Powerline program in the state."

Iowa Wind Energy Association supports Clean Line's transmission project

Harold Prior, Executive Director, with the Iowa Wind Energy Association (IWEA) submitted a statement in support of Clean Line's HVDC transmission project. 

The IWEA statement reads, "The project will result in the construction of many more wind farms in NW Iowa which results in more jobs, increased land lease payments to landowners and increases in the local property tax base which will provide more tax receipts to counties, cities and school districts.  We already export much of the wind energy generated in Iowa and IWEA supports the concept of Iowa continuing to grow its exports of electricity as well.  If we lead the nation in the production of corn, soybeans, hogs, cattle and eggs; why not electricity from wind energy as well!"

At the O'Brien County Fair in July, a poll was taken. After explaining the project's scope, the question asked was, "Are you generally supportive, unsupportive or not sure about the Clean Line transmission project?" Among fairgoers—mostly landowners—a fair amount of support exists. The result shows that 69% support the project, 13% were unsupportive and 17% weren't sure.

Company assures landowners the power line will not interfere with farming

Some landowners offered suggestions while others expressed skepticism regarding wind energy's basic usefulness. Others adamantly insisted wind energy will always be more expensive than power derived from fossil fuel or nuclear power plants. By aligning the power line to follow half-mile lines, section lines and property lines, this may make the project more tolerable to landowners, some suggested. Fears of power lines angling caddy-corner across farm ground, knee-deep ruts and packed down soil not repaired, as contractors' move along the right-of-way, were expressed.

When asked at the O'Brien County Fair if he could support the project, one clearly frustrated Highland Township landowner stated, "I'm not the one to talk to about this. I'm disgusted at the wind farm developer I've been dealing with. They have been jerking us around for ten years now. The transmission line should have come first ten years ago, then the wind farm developers.  So I don't support it." However, another landowner with farm ground in four townships, Doyle Wilson, said, "I think this proposed power line will enhance the whole area."

Economic impact from Clean Line projects could benefit a wide area

The economic impact from the Clean Line projects could affect a wider area than just northwest Iowa. A non-profit, rural policy advocacy group based in Lyons, Nebraska, The Center for Rural Affairs, offered their assessment, "This line is a welcome opportunity for both Iowa and the region, as expanding transmission infrastructure is critical in the effort to better develop wind resources. Rock Island will bring economic activity to rural regions throughout Iowa, Minnesota, Nebraska and South Dakota by employing the work force necessary for construction, creating property tax revenue, opening the door to new manufacturing initiatives and enabling a new generation of wind projects."

Invenergy LLC is a Chicago based wind farm developer with plans to build a 500 MW, 333 unit wind farm in O'Brien County. Alissa Krinsky, Invenergy's director of communications, submitted this August 11, 2011 statement from the Company.

Their statement reads, "Invenergy is committed to our ongoing development of renewable energy projects in Iowa, and supports the efforts of those businesses working to increase the capacity and efficiency of the region's electrical power transmission grid.  These types of projects allow Invenergy and other developers to harness the wind resources of Iowa, and to deliver power to end-users."

Because the Plains & Eastern Clean Line 7,000 MW power line will start at Guymon, OK, and cross the state, the Oklahoma Farm Bureau offered a statement. In his statement dated August 5, 2011, Oklahoma Farm Bureau president Mike Spradling said, "Transmission lines associated with renewable energy, particularly wind generated power that will be shipped out of state, should not be given the right of eminent domain.  We are not necessarily against Clean Line Energy.  However, we do not support the use of eminent domain by a privately owned company."

In several states the four projects will impact, Clean Line has filed papers seeking public utility status. Oklahoma administrative law Judge, Jacqueline T. Miller, has ruled Clean Line should be declared a public utility and recommended to the Oklahoma Corporation Commission that Clean Line be granted this status. The three-member commission now needs to decide the matter.

In submitting general policy positions from the Arkansas Farm Bureau, Steve Eddington reports, "We oppose the use of eminent domain procedures to condemn land for private easements. In all eminent domain transactions, consideration must be made of the value of the property, replacement costs, relocation expenses, and the loss of income during the replacement/relocation period. Eminent domain laws need to be used for public use."

In their general position statement, they support the expansion of all existing forms of energy sources like coal, nuclear, wind, tar sands and oil shale development. The Arkansas Farm Bureau policy position also states, "We support the use of renewable portfolio standards to stimulate electricity production from renewable sources such as wind, bio-mass, solar, tidal, hydroelectric and methane from manure and landfills."

What is the future of wind energy? What advances are being made?

Clean Line Energy president Michael Skelly answered several questions via a phone interview. The first question asked was: Has wind energy reached a tipping point where it is now considered a significant, reliable energy source?

Considering all forms of renewable energy sources, "Some may consider 2009 as a tipping point. Wind energy led the way that year by producing the greatest amount of power generation. However, I'm not a 100% there yet. We can never expect to have windy weather conditions a 100% of the time. But we're certainly getting closer to a tipping point," said Skelly.

Skelly was asked, will the next great leap forward in the wind energy industry be related to advancements in technology, or related to legislative activity of some sort? Skelly answered, "In terms of growth, it's related to technology because turbine design continues to get better and better."

Skelly cited a study that was done comparing two wind turbines from a Storm Lake, Iowa wind farm. One turbine was built with 2000 technology while the other turbine had a much newer design. Skelly said, "The study showed that wind turbines with the newest technology were 50% more efficient than generators built just 10 years earlier." He offered this remark about other forms of electrical generation like coal and nuclear by saying, "Other energy sources produce waste products that we don't particularly want."

These HVDC transmission lines will help get wind energy to marketplace

What's going to make wind energy much more meaningful than it is now? Skelly was asked. "Just the continued effort to develop new technology will make a difference.  We also think HVDC transmission lines will become a big part of getting wind energy to the marketplace," Skelly suggested. "We don't really expect to develop any new or innovative technology with our transmission projects.  We are simply using well proven HVDC transmission technology from the past and improving on it."

When asked about the future of the wind energy industry, Skelly concluded, "I think it looks great because we are going to continue consuming more electricity all the time.  Wind energy does not go way.  It's always going to blow."

Information about Clean Line's other HVDC transmission line projects

Besides the Rock Island Clean Line Project, Houston-based Clean Line Energy Partners has three other HVDC transmission projects in various stages of development meaning an estimated investment of $9.4 billion combined.

The thrust of Clean Line's plan for shipping wind power from the High Plains areas of Western Kansas, Eastern Colorado, Eastern New Mexico and the Oklahoma and Texas Panhandles is ambitious and enormous, to put it mildly.

Mother Nature's frequent creation and movement of weather systems, and the elevated terrain, cause wind in this region to blow almost all the time. Thus, this vast area has always been recognized as a prime region for wind farm construction. Wind farms continue to sprout at a steady pace. 

The 800-mile Plains and Eastern Clean Line Project is likely to be two 3,500 MW, HVDC transmission lines starting at two AC to DC converter stations near Guymon, Ok. One eastern terminus will be near Memphis, Tenn., where a DC to AC converter station will connect on to the Tennessee Valley Authority system for distribution of three-phase, AC power to smaller utilities in the Southeast. 

"Right now our focus is on the first 3500 MW line which is from Guymon to Memphis," said Galli. "The other terminus is undetermined." 

The Grain Belt Express Clean Line Project calls for the construction of an 800-mile, 3,500 MW HVDC transmission line that's to begin in West Central Kansas, near Spearville. The eastern terminus will be at converter station at St. Louis for three-phase, AC power distribution to it and areas further east.

The 3,500 MW Centennial West Clean Line is to start in Eastern New Mexico and end in Southern California. Exact start or end point has yet to be determined. The Spearville to St. Louis and the Guymon to Memphis lines do face one threat that every transmission system in this region faces. Both HVDC lines start at the western edge of Tornado Alley and then cross the full extent of this region. 

Galli, the Clean Line Energy vice president, says, "To design specifically for tornadoes would be nearly impossible because the wind loads are so unpredictable. The potential for debris impact to the cables is so great that the best one can do is to design structures that will withstand damage. The best defense against failure of structures is to have a good recovery plan with spare structures, hardware and cable that can be mobilized and installed quickly."

Clean Line's communications director, Sarah Bray, says, "We haven't purchased any transmission structures or overhead cable, yet. But we have established preferred provider relationships with General Cable of Arkansas and Pelco Structural of Oklahoma. We are currently in the process of pursuing additional alliances with local vendors to source materials for our projects." The preliminary agreement with Claremore, OK-based Pelco Structural LLC, for instance, is to buy 800 miles of tubular steel transmission poles to span the distance from Guymon to Memphis. General Cable is to provide aluminum transmission cable.

Clean Line intends to fund the development and construction costs for all projects. To recover their investment, Clean Line will sell transmission capacity to renewable energy developers and to the local utilities that purchase the power.

Considering all four projects combined, Bray says, "We've been in contact with more than 30 wind developers. Yes, we have held discussions with Invenergy, Florida Power & Light, Eurus and E.ON from Germany."

The last four wind energy developers have been looking to build wind farms in O'Brien County for as long as ten years now. Long term shipping agreements with wind energy developers are due to be finalized in 2014. The Rock Island Clean Line could begin operating in 2016.

Editor's note to readers: Following is a sidebar story to go along with the main story above. This sidebar explains the technical aspect of shipping electricity generated by wind turbines, with a look at how the proposed high voltage direct current transmission lines work.

Direct Current Transmission: Looking At 60 Acres of High Technology

By Loren Gaylord Flaugh

Though high voltage direct current transmission (HVDC) lines have been in existence for 60 years now, Houston based Clean Line Energy's application of  shipping HVDC electricity from wind turbines will be unique in one respect. 

The company's communications director Sarah Bray points out, "Several HVDC lines do exist; however, they were not constructed specifically for delivery of electricity generated from wind resources. In the U.S., these could be the first HVDC transmission lines specifically constructed to bring the country's best wind resources to market centers."

Most interstate transmission lines are high voltage alternating current (HVAC) facilities, but Clean Line believes, and independent studies show, HVDC overhead lines move significantly more power with greater efficiency over longer distances. Situated on a 60-acre site at each end of the proposed transmission line would be a $250,000,000 converter station with a companion HVAC switchyard and transformer complex. By reason, the potential site in O'Brien County would be near an existing 345,000 volt (kV) Mid American Energy AC transmission line.

Wayne Galli, vice president of transmission and technical services for Clean Line, explains, "The 345 kV transmission line that runs from the Raun substation near Sioux City northeast through O'Brien County is of importance to our project as currently configured. An HVDC converter station needs a very strong AC network to provide a voltage reference for it to robustly convert AC to DC.  Therefore, an interconnection to the existing 345 kV network is necessary."

Electricity will be converted to DC power for transport on the power line

So, how's all this stuff work?  Voltage collected from area wind farms arrives at the AC switch yard where a step-up transformer boosts the voltage to the required transmission line voltage of 600,000 volts.

After leaving the standard iron-core AC transformer, the voltage enters what's called a rectifier circuit where the conversion to DC begins. The rectifier circuit is comprised of a high-voltage triggered diode called a thyristor. The simplest rectifier circuit consists of a single thyristor, an inductor and an AC current supply.  For the largest commercial applications, however, twelve thyristors are used to form a 12-pulse converter bridge to smooth the output for connection onto the transmission line.

According to research from Stanford University, during the last 20 years, power companies have been pushing the state of the art in thyristor technology, more than doubling the device's throughput and increasing its voltage by 50%. 

After leaving the rectifier circuits, the DC voltage is then connected to the long haul transmission line for shipment to the Chicago metropolitan area. The DC voltage then goes through another converter station where an inverter circuit returns it to three-phase AC. Another AC transformer and switchyard then lowers the voltage for connection onto the power grid.

Though the 3,500 MW of power flowing through the overhead transmission wires is HVDC, both the input and output of the complex, expensive system is HVAC.

Direct current transmission systems have advantages. First, they can transmit nearly twice as much power when compared to AC systems of equal voltage. Second, control of the rectifier and inverter circuits makes it easier to synchronize input and output to the phasing of the HVAC power grid on either end.

The AC-to-DC converter stations on either end are extremely expensive

However, an HVDC system has one huge disadvantage. The AC-to-DC converter stations on either end are extremely expensive. Still, there is a break even point where a HVDC transmission system becomes cheaper. It has to do with the length of the line. When the transmission line is longer than 500 miles, HVDC becomes cheaper than an HVAC transmission line. Construction costs for an HVAC transmission system are more expensive. This is due to the smaller transmission structures and fewer overhead cables of the HVDC system.                   

Bray says, "We have signed an agreement with Siemens to provide HVDC technology solutions for the Rock Island Clean Line transmission project. The current lead time from the design phase to the fabrication phase to the full operation of a converter station is roughly three years from the time of notice to proceed. Our goal in partnering early with select technology vendors is to reduce the time spent on engineering so that this timeframe may be reduced. The HVDC converter stations are engineered by highly specialized technology vendors."