Electric Highways in the Sky
By Kaye Northcott
‘There continue to be more and more parts of your electric bill over which we simply do not have control.’
Roland Witt, General Manager
Coleman County Electric Cooperative
Texas is requiring utilities to generate 5,880 megawatts of electric power from renewable sources by 2015 and 10,000 megawatts by 2025. No problem there. Wind power entrepreneurs have created a new energy boom in West Texas. There’s already more wind electricity available than the limited transmission system in the region can handle. And hundreds of private companies have proposed new electric highways. They are waiting for the Public Utility Commission of Texas to determine who will get the cost-plus contracts and where the lines will be constructed.
Most of us would like to be spared the gritty details about the cost of producing electric power. Talking about the cost and reliability of transmission seems even more deadly dull. But Texas Co-op Power feels obliged to bring co-op members an explanation of what we have control over and what we don’t. Today’s subject is transmission, the electric highway in the sky that needs new routes, just like our vehicular highways do.
If you need motivation to read this, all you need to know is that you will pay the cost of these new transmission lines in your monthly electric bills.
The new energy kid on the block—nonpolluting wind—is strongest in the Panhandle and West Texas, but the greatest power need is in the more populous region farther east. So to get those cheaply generated electric volts from sparsely populated West Texas to the big markets, billions of dollars must be spent to build electric lines. And new procedures must be designed to harmonize the output of wind farms with electric energy generated from other sources, mainly natural gas, making sure the instantaneous production of power meets the instantaneous needs of millions of Texans. The new lines must also alleviate congestion around Dallas/Fort Worth, San Antonio/Austin and Houston.
A ballpark figure on the cost of constructing a mile of 345,000-volt transmission line is $1 million, about the cost of building a mile of asphalt highway. The Electric Reliability Council of Texas (ERCOT), the nonprofit grid operator, issued a report in April indicating that constructing transmission lines to transport wind-generated electricity from west to east will require an investment of anywhere between $3 billion and $6.4 billion over the next few years. The ERCOT grid covers about 75 percent of the state and represents 85 percent of the state’s electrical load, including that generated by cooperatives.
THE WIND IS FREE, BUT THE HIGHWAY IS NOT
The Fort Worth Star-Telegram estimates that the most ambitious transmission plan could cost Texans within ERCOT $320 per capita. Barry Smitherman, chairman of the Public Utility Commission of Texas (PUCT), estimates that new wind power transmission should cost individual consumers no more than $4 a month. The Wind Coalition, an association of wind energy businesses, promptly responded to the ERCOT estimates by saying that savings from wind-powered electricity can offset the transmission construction costs within two years by replacing more expensive forms of energy. This could be correct, but the figures come from wind-farm entrepreneurs who are proposing to build more wind farms than Texas could possibly accommodate in the near term.
Cooperatives have a limited number of transmission lines (Brazos Electric Cooperative has 2,577 miles of transmission line, the most of any Texas co-op generator). Although cooperatives can monitor the transmission expansion plans of others and propose new routes that they consider necessary to meet their member loads, co-ops have no authority over where the lines will go or what they will be charged to use them. PUCT makes those decisions.
ERCOT estimates that between 1,600 and 3,000 circuit miles of transmission will have to be constructed in the next five years. The latter figure would be sufficient to carry 17,956 megawatts (MW) of wind-generated electricity. One megawatt provides approximately enough energy to light 500 to 700 homes when the wind is blowing. That equals between 9 million and 12.5 million homes. As of 2000, the U.S. Census Bureau reported that the state had 7.4 million households.
WIND MUST HAVE A PARALLEL POWER
Even if transmission facilities were constructed to connect and transmit all this proposed wind generation, wind energy alone still could not provide reliable service. Because wind energy is intermittent, there always must be conventional generation, primarily natural gas or coal, ready to supplement electricity when the wind either dies down or blows so hard wind generators cannot operate. Electric is also needed to provide what are called “ancillary” transmission services, such as maintaining proper voltage throughout the transmission grid.
Are consumers going to be required to pay for more transmission lines than are needed because more wind farms are being built than can be used? When there’s more electric power available at a particular time of day because the wind is blowing, will conventional plants that burn coal or natural gas have to curtail their output for a few hours? Who decides which electricity uses the grid and who profits? These issues will be in play with wind power and perhaps later with large-scale solar power.
Renewable power, particularly wind, will absolutely be part of all Texas electric companies’ generation portfolios in the future, no matter what kind of new construction is needed. State law requires increasing use of renewables. The bulk of the power is to be transmitted to the populous areas of Dallas/Fort Worth, Austin/San Antonio and Houston. PUCT is studying four proposals that would transmit from 12,000 to 24,000 MW. The agency also will designate specific routes. Wind farm entrepreneurs are participating in routing negotiations. Transmission construction for this round of wind farms should be complete in five years. Proximity to a transmission line may mean the difference between financial success and failure.
There’s even disagreement about how much capacity is available in existing facilities when wind developers who want to use the lines come up against the reliability concerns of transmission operators. As Kenneth Starcher, director of the Alternative Energy Institute at West Texas A&M University, explained, “Imagine a pipeline is half full. Wind farm developers look at a line with only 50 percent of load and see 50 percent unused. The utilities say they need the extra capacity for emergencies, for reliability. The utilities have to plan for the worst possible scenario because the available electric power changes all the time.”
Although the new transmission facilities will raise costs for co-op customers in ERCOT, there is no question that the existing shortage of transmission facilities also can affect what people pay. When transmission lines are not adequate to bring the lowest cost power to an area, they are called “congested,” and the lost opportunities to use lower-cost power are called congestion costs.
In West Texas, one also hears about “stranded” wind. That’s the potential available electricity from already constructed wind farms that has no transmission outlet. Sometimes the fate of electricity generated by wind and coal (a major source of CO2) are conjoined. For example, when the state of Kansas denied an air permit to construct the Holcomb coal plant, developers scrapped plans to build transmission lines from Kansas to the Texas Panhandle. Those same lines would have scooped up stranded wind power and transmitted it to waiting customers on the Southwest Power Pool grid.
Ultimately, PUCT must decide how much additional transmission should be built, where it will be built, who will build it and, of course, who will pay for it. There also will be questions regarding just how much wind can be reliably integrated in the ERCOT grid. “Hopefully, the Public Utility Commission will give thoughtful and objective consideration to these complex issues,” said Greg Jones, chairman of the board of Texas Electric Cooperatives and manager of Cherokee County Electric Cooperative Association.
SIDEBAR: THE OTHER GRIDS
Four grids touch Texas. Each grid performs intricate adjustments to transmit exactly the amount of electricity customers need at the instant they want it. Since electricity can’t be stored, this balancing act involves thousands of calculations over the state’s various grids at five-minute intervals. Generators must respond instantaneously to changes in consumers’ load.
ERCOT, the state’s largest grid, is not the only regional transmission organization experiencing growing pains.
The need for new transmission infrastructure is just as crucial in the Southwest Power Pool (SPP) and two other grids that serve parts of Texas.
SPP serves parts of eight states. SPP supplies electric transmission paths for portions of the Texas Panhandle, South Plains and Northeast Texas.
The SERC Reliability Corporation (SERC) is responsible for transmission services in part of Southeast Texas, and the Western Electricity Coordinating Council (WECC) picks up the western tip of Texas, including El Paso.
All these organizations are charged with ensuring the reliability of electric service by setting standards governing the operation of both generation and transmission facilities and monitoring the flow of power over transmission lines.
Grid operators must handle transmission congestion, which is much like highway congestion. It occurs when large amounts of energy (cars) want to travel on limited-capacity transmission lines or flow paths (roadways).
The system operator will manage the output of the various generation resources and may limit the amount of energy that can flow on congested lines or paths to assure that maximum operating limits for the transmission lines are not exceeded.
If the grid becomes unstable due to the loss of generation or transmission facilities, the grid operators will take corrective action, including such measures as ordering rolling blackouts.
In order for grids to freely exchange energy, they must be synchronized with each other. SPP and SERC are part of the Eastern Interconnect, which is not synchronized with either ERCOT or WECC.
SPP has proposed transmitting wind electricity from the Panhandle east across Oklahoma until it reaches a point where it could be transferred to the ERCOT grid to serve Dallas/Fort Worth. The idea has been nixed by ERCOT. Under the ERCOT plan, wind power from the Panhandle and West Texas will move over new lines that will be directly connected to the rest of the ERCOT grid.
Spokespeople for all the grids say they are improving their services. In January, the SPP board approved a $2.2 billion transmission expansion plan for 2008-17.
Some of the thorny ERCOT transmission issues before the Public Utility Commission of Texas (PUCT) include:
Q. Who will be selected to build the transmission lines needed to reap wind electricity?
A. Many companies are competing for PUCT approval to build the transmission lines needed to transmit wind energy from the Panhandle and West Texas to other parts of ERCOT. Under the PUCT rules, transmission owners are guaranteed recovery of their costs and a return on their investment. This makes investment in transmission facilities very attractive.
Q. Where will the new transmission lines be built?
A. The PUCT has already designated four zones in the Panhandle and West Texas that have the most active wind- energy businesses and the greatest potential for production. Detailed transmission routes are being studied.
Q. Who pays for what?
A. Wind farms must finance the “gathering system” of lower-voltage lines needed to move wind energy to the “backbone” system of higher-voltage lines, including new 345,000-volt lines, that will then move electricity from the western part to the eastern part of the state. The cost of the backbone system is paid by all users of electricity in ERCOT, whether or not they actually receive any wind energy.
Q. Will all wind farms have the same access to the new transmission facilities?
A. The ultimate routing of the new lines will have a significant impact on how much it costs a wind generator to connect to the high-voltage lines. The farther a wind farm is from the new high- voltage transmission lines, the greater the cost to construct gathering system lines needed to reach the high-voltage lines.
Q. How will costs be allocated to electric users throughout the system?
A. Like Americans pay for postage stamps. A first-class stamp costs the same whether a letter is carried across town or across Texas. All retail electric users in ERCOT will pay the same transmission cost per kilowatt-hour for the electricity they use.
Kaye Northcott is editor of Texas Co-op Power.