"The Most Significant Engineering Achievement of the 20th Century"1
by Cathy Day & Kevin Gibbons
Although we may recognize our dependence on electricity when we flip a switch or take a cool drink from the refrigerator, we may have little thought for how the electricity arrives at our homes. All of the public discourse seems to be centered on production and consumption - like coal-fired power plants and efficient light bulbs. Only if a high-voltage line is proposed for our area are we likely to take note of the issues surrounding transmission. How does the electricity get from that coal plant to our light bulbs? Beyond our local area, why should we care about the electric grid? This primer condenses information about power lines, voltage, rural electrification, regulation, and policy to provide an overview of how electricity transmission affects our lives.
The United States at Night2
Table of Contents
- What is the grid?
- Where is the grid?
- How has the grid become what it is today?
- Who benefits from the grid? Who suffers from it?
- Who controls and regulates the grid?
- Why do people argue about the grid?
- To Learn More
- Works Consulted
What is the grid?
The electric grid is a series of transmission wires, metal towers, voltage converting substations and their associated control structure. The "Where Is the Grid?" below section goes into more detail on such grid infrastructure. This section looks at the system as a whole.
Current and Voltage
An analogy between electricity and water in pipes helps explain current and voltage. Current is like the amount of water flowing through the pipe, and voltage is similar to how much force is pushing the water through the pipes. More current creates more resistance in wires.
AC, DC, and HVDC
Direct current (DC) is an electrical current that flows one way through a circuit. Batteries are a good example of DC that is frequently used in our households. Notice that batteries always have a positive and a negative end. In a direct circuit, the voltage source circulates current one way (as shown in the diagrams below and in the color section), and the voltage must be held constant.
Alternating current (AC) is an electrical current that changes direction frequently and cyclically. AC has been preferred over DC for home and office consumption because 1) AC can be distributed over long distances without losing much electricity as heat, and 2) it is much easier to increase or decrease the voltage of AC using transformers. Therefore, utilities are better able to produce energy at a high voltage from a central generator and distribute that to homes.
For transmission of bulk electricity across distances of hundreds of miles, high-voltage direct current (HVDC) lines are more efficient, but they require expensive conversion infrastructure.4
The United States electric grid grew up over time from being a very local phenomenon to a much more nationally and even internationally integrated entity, but it is still a very loose affiliation of regional grids. Power in the U.S. is circulated within separate regional grids, with some direct current (DC) connections between them that are more easily controlled than alternating current (AC) connections [see "AC and DC" for more information]. Modern DC connections can allow power transmission that is controlled and keeps regional grids separate from one another. For example, the western states of the U.S., along with the western provinces of Canada, largely keep their power to themselves, and Texas has few connections with any other state.3 Yet, several parts of these systems are connected with non-regional systems with interties, or high-voltage, often DC, connections.
Despite these separate zones, within zones there is a high interdependency among the members of the grid. The interconnected system helps keep costs down, decreases the risk of problems like blackouts, and allows areas of high power production to be linked with areas of high power use. The least expensive power plant available to the system can, in theory, push other power generators to become more efficient or shut down. The more power production plants that connect to one another, the more ability the system has to continue to produce power when one plant unexpectedly fails.5 Having a variety of power plants also helps ensure that if coal costs suddenly rise or water supply is drastically diminished, the cost and supply of power do not drastically change.6 Areas with heavy potential for wind power production can, all else being equal, send their power over the grid to reach consumers hundreds of miles away.
The set of smaller grids that make up the international grid are connected together with varying degrees of interdependence. For example, most of the midwestern U.S. is part of the Eastern Interconnect, which links AC power systems all over the eastern U.S. and Canada except for Quebec. Within the Eastern Interconnect, however, different subgroups, called regional transmission organizations (RTOs), control different areas of the grid. For example, within Wisconsin, the grid is controlled by the Midwest Independent System Operator. Reliability control in Wisconsin, on the other hand, is shared between the Midwest Reliability Organization and the ReliabilityFirst Corporation, which also serves Chicago and other states to the east.9 Each of these subareas is connected within the Eastern Interconnect, and the Eastern Interconnect itself is connected via interties (see "A DC Example" box) to the Texas, Quebec and Western regions.
Environmentally conscious consumers of energy have many reasons to closely follow the grid's development. The wide range of alternative energies being explored - from solar to wind to storing electricity in electric hybrid cars - require increasing coordination of the grid. Wind and solar, for example, only produce energy when the wind is blowing or the sun is shining. Since regulations require the system to have a continuous source of power to meet customers' demands,10 wind and solar must be operated in tandem with other systems that provide power at night and when the wind is not blowing. The need for steady sources of backup to wind power were illustrated vividly in Texas in 2008, when 1,100 megawatts of power was cut from "interruptible" (usually industrial) customers because wind speed quickly dropped and power demand was rising.12 (Interruptible customers usually agree to the possibility of being cut off from power in exchange for lower rates. They tend to be heavy users of power.)13 Most areas of the grid would have been able to draw on power from other areas, but Texas's grid is largely separate from the rest of the country. The Texas example highlights the need to ensure backup power, storage or demand response (cutting off power to certain customers) for some renewable power sources.
Source: POWERmap, "Electrical Transmission," Platts, A Division of the McGraw-Hill Companies, 2009. Retrieved from http://teeic.anl.gov/images/photos/Argonne_transmission_USA.gif
Where is the grid?
Power failures of 1965 and 2003
On August 14, 2003, a high voltage line in Ohio sagged down into an untrimmed tree and began the cascading power failure that resulted in the largest blackout in American history.
Power lines are made to shut down in such conditions, to help ensure human safety and continued power distribution. When one line shuts down, current moves to the line with the most room to flow. As one line after another in Ohio became overtaxed and overheated and sagged into untrimmed trees, more and more power was forced onto the rest of the Eastern Interconnect and the system became strained, causing power generators to shut down.
The warning systems in Ohio should have told the system controllers that the line was down, but they failed. The highly interconnected nature of the grid was meant to ensure that failure of one part of the system would not mean failure for the rest of the system, but without knowledge of what was happening, the network's problem spiraled out of control. Fifty million people lost power for as much as two days.7
Such failures were nothing new. November 1965 saw a similar blackout in the northeast that affected 30 million people. The cause in 1965: one faulty relay in Ontario that caused a similar series of system overloads and subsequent failures, leading to the blackout that hit New York City at 5:27 p.m. In 1965 the power was mostly back on by the middle of the night. Yet the knowledge of how the failure happened, investigated in subsequent days, did not prevent the same thing from happening in 2003.8
In some senses, the grid is everywhere, but it is more concentrated and apparent around power plants and in the substations where the voltage is altered to make it safer or to increase its travel efficiency. We also tend to notice it where high voltage transmission lines, with metal towers that dominate the landscape, run close to us.
The grid tends to be most present in areas where power is most needed for homes and industry, called load centers. The reasons for this are various, but one of the most important is the electricity that is lost along transmission lines. Most transmission lines are alternating current (AC) lines, so some electricity is lost as heat over vast distances.15 So, despite the advantages of grid interconnection, it does not necessarily end up making sense to build massive coal-fired power plants just outside of the mines in Wyoming if we are trying to entirely power Los Angeles or Chicago. This becomes an increasingly important issue as we work to find renewable power alternatives. The best sources of wind and solar power, for instance, are not necessarily close to the places that need them, like the Eastern seaboard.
One solution for efficiently sending power over long distances is using high-voltage direct current (HVDC) instead of AC. Per mile, HVDC loses less of the energy produced than AC does.16 The problem is that HVDC is more expensive than is AC transmission due to the complexity of equipment used to convert between AC and HVDC.17 It is in use at a few locations that connect otherwise separated grids (e.g. connecting Hydro Quebec's system to the large Eastern Interconnection system that covers the eastern U.S.), but most connections are AC.
The electric grid infrastructure dominates parts of our landscape, but we often tend to pass by it without knowing exactly what we are looking at. We know, for example, that high-tension lines carry electricity, but why are they different from the wires that lead to our homes? There is more on some of the technical reasons for the grid infrastructure in the next section, but here is a summary of what we see in the landscape:18
These take a variety of different forms, from coal-fired to solar to hydroelectric, but all are the source of electricity generation. To transmit their electricity over long distances, the electricity is transformed into higher voltages.
Step-up Transmission Substations
Step-up substations take power plant-generated power and convert it to higher voltages for long distance transmission.
Step-up Transmission Substation19
High voltage electricity is carried along high voltage power lines that are supported by the immense metal towers like the one in the picture.
The Texas Power Grid
Texans have a long history of desiring a high level of independence from the rest of the U.S. The electric grid is no exception. In 1941 the state's electricity producers joined forces to ensure that Texas-produced electricity went to Texas industrial production for the war effort. In 1970 NERC gave authority to a Texas-only entity, ERCOT, to maintain Texan grid reliability-- separate from other grids.14
Electric Transmission Lines20
Step-down Transmission Substations
A DC example: the Pacific DC Intertie
The Pacific Northwest and Los Angeles are connected by the Pacific DC Intertie. It is a high voltage DC transmission line which can send power either north or south. The intertie sends power in whichever direction has the highest needs at a given time. For example, the Pacific Northwest may use more power in winter for heat, and Los Angeles may use more in the summer for air conditioning. So, the Pacific Intertie nicely serves as a way to share power between the two areas.11
Figure: The Pacific DC Intertie http://en.wikipedia.org/wiki/File:Pacific_intertie_geographic_map.png
These substations convert high voltages into lower voltages, or "subtransmission" voltages. Power from step-down transmission substations may be sent directly to industrial facilities with high power needs, or may be sent on for distribution to smaller customers.
At distribution substations voltage is dropped again and is then distributed to both commercial and residential customers.
Utility Pole or Underground Transformers
At utility poles near houses or connected to underground wires, these transformers convert the distribution voltages to the levels we use in the home. Voltage usually decreases to 220-240 volts inside houses and is halved again for many uses.21
A pole transformer converts voltage from high transmission voltages to lower voltages for use in the home.22
Putting it all together
In order to transmit electricity efficiently, minimizing heat losses, power transmission companies send their power at very high voltages over long distances. Voltages on these wires are as high as 765 kilovolts (or even 1,000 kilovolts). At high voltages, little current is required, and it is high current that causes the most resistance in the lines and therefore the most energy lost along the way.23 These high voltage lines run along the huge, metal towers we often see in more open landscapes. That power has to be returned to lower voltages to make it safer for use. At distribution substations (fenced-in areas with various coils and boxes where you will often see many electric lines entering and leaving), the electricity's voltage is reduced, often to 7.2 kilovolts (7,200 volts). Transformers are an important element of substations. Transformers can change low voltage into high or vice versa. Transformers function by running alternating current through various numbers of coils next to another set of coils. If there are more turns in the second coil than in the first, voltage will increase, and fewer turns decreases voltage. That electricity is redistributed and then passes through further transformers when it reaches customers. For example, when electricity runs through a transformer that may be located on a pole near your home, it is converted into 240 volts that some of your larger appliances run on. Many household uses require only 120 volts, and thus use only half of the power (supplied by one of the two wires carrying 240 volts into the home) that is brought into the home from conversion.24
NERC Interconnections (in quote boxes) and regional reliability councils (differentiated by color), http://en.wikipedia.org/wiki/File:Nercmap.JPG.
How has the grid become what it is today?
The story of the growth of the grid is inseparably weaved with increasing demands for electricity over time. Inventions have been the mother of necessity, as far as our power demands are concerned — inventors and political actors have also had a lot to do with it. The grid is the result of a national project to deliver electricity to all.
This brief, historical narrative of the progression of the American electrical grid is divided into three parts:
1. Urban electrification, focused mainly on Chicago (1880-1935)
2. Rural electrification (1935-1970)
3. The grid today (1970-present)
The grid has a long and complicated history. This section sketches just the broad social forces and key historical actors that shaped and were shaped by these technologies.
The City Alight (1880-1935)
The initial development of electricity was driven by a desire for brighter, cleaner, safer lighting and for mechanical substitutes for transportation by horse. By the 1870s and 80s, inventors and entrepreneurs throughout Europe and North America were dedicating themselves to harnessing the power of electricity.25
Chicago provides an excellent example of how the grid came to be, as one of the foci of early grid integration.26 Electricity entered into Chicago spaces rather chaotically. Many small-scale companies sprang up throughout the city utilizing different systems with different advantages and disadvantages. One major element of competition between them was centralized versus self-contained production systems.27 Thomas Edison's electric utility model, with a central generating unit connected to a larger grid, and George Westinghouse's addition of alternating current into the grid system,28 soon became the dominant model adopted in Chicago and other cities.
"Edison Jumbo Dynamo No. 1," Department of the Interior, National Park Service. 1881: http://www.nps.gov/archive/edis/edisonia/graphics/15400008.jpg.
Using Edison's centralized model, Chicago Edison Company (CEC) and the Chicago Arc Light and Power Company came out ahead of their competitors. Those companies acquired many of the numerous smaller companies in the Chicago area and were given permission by the city to string above-ground electrical lines to distribute power. They supplied lights and electricity to their users. Soon they had overlapping networks in the city and were competing for customers. By 1892 CEC had a generator capacity of 3,200 kW and supplied 43,200 incandescent lights throughout the city.
Access to electricity was initially only possible for businesses and the affluent, but no one ever doubted that electricity would take over from dirtier, less healthful gas lighting: "Chicagoans increasingly linked things electrical with notions of amenity, class, and modernity."29
Businessman and investor Samuel Insull was one of the major forces behind the creation of today's integrated grid. While he is responsible for many innovations, his disputably most influential contribution was how he was able to cultivate consumer demand for electricity through novel management practices. He became President of CEC in 1892 and undertook his ambitious vision of delivering central station service throughout the entire city. Under Insull's management, CEC instituted an AC-DC system, which uses alternating current and to raise the voltage for use in transmission, requiring substations with transformers and converters to lower the voltage to meet the needs of the district and convert to direct current. The system made electricity more affordable. Insull also oversaw the adoption of meters (which were already in use in the UK) to monitor consumption. Perhaps more pivotal than the adoption of an AC-DC system or meters was Insull's innovative way of billing electricity consumers - a scheme that is still in use in the U.S. today. Insull wanted to provide power to all types of consumers, thus increasing electricity consumption. He helped encourage consumption by adopting a billing scheme that charged heavy consumers lower kilowatt-hour rates than small consumers.30
Insull rose quickly, acquiring companies, wealth, influence, and notoriety. By the time of the stock market crash in 1929, he was a multi-millionaire who controlled 60 utility corporations. He ended up losing the majority of his wealth in the Crash. His name was associated with the "Power Trust," a group of electric companies owned by the Morgan Bank, the Mellon family, and the Duke family, among others, that were implicated in forcefully suppressing the availability of electricity, especially to rural consumers.31
While his name was heavily marred by the end of the 1930s, Insull's dream had been carried through: the Chicago region was mostly alight with an integrated grid. The future drivers of increased demand for electricity were more household electrical appliances and expansion of electricity into the rural areas. However, utility companies were financially crippled by the stock market crash and politically crippled by news of the "power trust." The resultant public distrust of utility companies and the election of Franklin D. Roosevelt partially set the stage for rural electrification driven by government grants and local power cooperatives.
Bringing the Farm Family out of the Dark (1935-1970)
The Milwaukee Electric Railway and Light Co., "The Electrical House that Jack Built," Milwaukee, 1916. Accessed through the Wisconsin Historical Society: http://content.wisconsinhistory.org/cdm4/document.php?CISOROOT=/tp&CISOPTR=50415&CISOSHOW=50394.
In 1935 the editor of Wallace's Farmer, a Midwestern journal, wrote of his trip through the Iowa countryside that "too many farm people were living in the dark or the half-dark ... the contrast between the town and the country was the contrast between electricity and the old oil lamp."34 By 1930 13% of the country's farms had electricity, compared with 85% of non-farm households. There seemed to be a widening disparity between urban and rural, rich and poor, and disseminated information concerning power and rural electrification focused on modernizing farm families and relieving the labor burden of the farmer on his field and his wife in the household. 35
Utility companies were slow to expand to the rural areas, claiming that electrifying sparsely populated areas was not profitable. Rural residents founded electric cooperatives as a means for households to gain access to electricity. Members bought shares, and the cooperative built transmission lines to connect the communities that they served to the utility companies' lines.
Cooperatives were not new to farm households. Electric cooperatives were in part modeled on the Canadian and European systems, but they also built upon the telephone cooperative model that many areas had adopted.
Between 1930 and 1935 the Tennessee Valley Authority was established, the Hoover Dam was completed, and the Works Progress Administration (WPA) was created. Within this context the Roosevelt Administration and Congress passed the Rural Electrification Act, which established the Rural Electrification Administration (REA) to bring electricity to rural households. Morris Cooke, whose ideas inspired the structure of the REA, was appointed as its first head. Politicians were very wary of utility companies at the time, so co-ops were assigned preference and received many of the government development grants and loans, which were the main financial drivers of the REA. The legislature also passed the Public Utility Holding Company Act (PUHCA) in 1935, which established electricity generation and transmission as a regulated industry. Thus, the grid progressed through decentralized and regulated local distribution networks throughout the American countryside.
In terms of electrifying rural households, the REA was an overwhelming success. Almost no corner of the U.S. is without access to electricity. These changes in the countryside were enacted in a short time: 11.6% of rural households had access to electricity in 1935, and 90.8% had access by 1953.36 Considering the huge land area and the fast pace of the electrification, it is easy to see why some people would call the grid "The Most Significant Engineering Achievement of the 20th Century."
Source: U.S. Department of Agriculture. Rural Electrification Administration. "Brief History of the Rural Electrification and Telephone Programs," April 18, 1982 (accessed at http://rurdev.usda.gov/rd/70th/rea-history.pdf).
The Grid as We Know It (1970-present)
Forming "The Grid"
When did the US first start to have something that we would recognize as "the grid"?
Let's start with a definition. There are many ways to define an "electric grid," but we liked this one best: "a network of synchronized power providers and consumers that are connected by transmission and distribution lines and operated by one or more control centers."32
Going by that definition, the answer to our question is "1927." In 1927 the Public Service Electric & Gas Company, Philadelphia Electric Company, and Pennsylvania Power & Light Company formed the Pennsylvania-New Jersey Interconnection, which was the first "continuous power pool" that resembled the vast network of transmission lines that we have today.33
During the late 20s through the 50s local utility companies linked their local transmission systems to form small networks or "power pools" that jointly owned power plants and/or connected neighboring transmission networks to facilitate power sales.37 These utilities still operated in limited areas and were "vertically integrated," which is to say that they were in charge of producing and distributing electricity to their localities.38
Electricity as a Commodity
Starting in the late 1970s and progressing through the Reagan administration, the U.S. government deregulated certain facets of the grid and energy markets emerged as corporations began to exert greater influence on the multiple facets of electricity.39 Power plants were bought and sold, and corporations that had a wide range of assets were now utility operators. Electricity became a commodity, and people began widespread trading in electricity contracts, futures, and other derivatives.
As electricity was further deregulated, the Federal Energy Regulatory Commission (FERC) responded to the need to ensure reliability by encouraging the establishment of regional transmission organizations (RTOs). The FERC requires any companies that control electric transmission facilities to participate in an RTO in order "to promote efficiency in wholesale electricity markets and to ensure that electricity consumers pay the lowest price possible for reliable service."40
Electricity production and consumption in the U.S. began with utility companies delivering service to customers in dense cities around the nation. As the gap of access to electricity widened between rural and urban residents, the Roosevelt administration established the REA, which oversaw the creation of the vast network of infrastructure that is so visible on the American landscape. Today, electricity is a partially regulated commodity that is transmitted through that network, and federal and state politicians continue to argue for the merits of more and less regulation.
Who benefits from the grid? Who suffers from it?
Enron and the Fragile Network
The complexity and vulnerability of the energy market and the networks that it affects was most noticeable in recent history between 2000 and 2001 when California experienced 38 rolling blackouts. It later became clear that these blackouts were the result of the Enron Corporation manipulating the price of electricity by intentionally removing power from the market by shutting down power plants.41
The grid can benefit all of its users, from power producers to electricity distributors to customers. They all gain decreased costs, increased reliability, and an increased possibility of using less polluting energy sources.
Negative impacts of the grid vary depending on the stakeholder. Users often do not want to see new power lines in their neighborhoods for both aesthetic reasons and worries about impacts to health. One review of health research found that electric and magnetic fields (EMFs) produced by power lines, wiring in buildings, and appliances may increase the risk of childhood leukemia, adult brain cancer, Lou Gehrig's Disease and miscarriage, but there has not been scientific consensus.42 Consumers may also be concerned about keeping prices down. Sometimes concerns over aesthetics and health clash with concerns over prices, as new lines can decrease prices due to more competition and higher reliability. Consumers may pay for new lines fairly directly as their utilities or new producers of electricity pass on their costs in rising consumer prices.43 Environmentally aware consumers may focus on how the grid allows for the use of alternative power sources.
Producers and distributors of power, as well as those charged with ensuring overall grid reliability, are most concerned with the continued and increased reliability of the grid and with keeping costs down. Increased interconnection is often seen as a benefit. Yet, the greater complexity of the grid, and higher level of central control can increase the chances that a small, seemingly isolated problem can affect the entire grid, as witnessed in the 1965 and 2003 blackouts.
Who controls and regulates the grid?
Despite the interstate nature of the current grid system, the federal government's control of power transmission through the Federal Energy Regulatory Commission (FERC) remains rather limited. It can regulate rates and transmission for investor-owned utilities (IOUs) (which comprise only a little more than half of utilities in some areas), but not for public-owned utilities (POUs), which are subject only to the regulation imposed by their own boards. In addition, following the 2003 blackout, Congress gave FERC the ability to give permits for new transmission lines that cross state boundaries, but to date courts have prevented FERC from issuing such permits if the states turn them down.44
States, too, are somewhat limited in their rights to regulate the power industry. Like FERC, their public utility commissions are allowed to control only investor-owned utilities. Some of the publicly-owned utilities are state-owned, which gives some states further power. Also, states do have the right to "set retail rates, review utility operations...and issue siting approvals (permits) for new transmission lines."45 The latter gives them more power over the siting of transmission lines than the FERC has so far been allowed to exercise. State power over permitting has tended to limit the introduction of new power lines, even in highly congested areas where new lines would decrease the likelihood of potential power outages.46 New lines are politically unpopular in some cases, since few consumers choose to have high-voltage transmission lines running near them.
Why do people argue about the grid?
The Smart Grid
Because the grid must instantaneously use the energy it generates, power generation and use must be carefully balanced. The smart grid is a series of infrastructure improvements that would help enable power generators to better create that balance, and potentially to reduce the need for transmission and peaker plant infrastructure over time.
One of the major ideas underlying the "smart grid" is that instead of relying on just increasing or decreasing supply, the grid could also signal users to decrease demand at crucial moments of heavy load. Advanced Metering Infrastructure (AMI) could allow consumers to set controls on their systems that signal their appliances to use power at times when demand and prices are low.
These systems can also better sense and respond to what is happening on the grid. In some places this capability is already well-developed, but designers are attempting to make such technology even more advanced, combining more detailed grid information with weather and grid modeling information.
Phasor Measurement Units (PMUs), located all over the grid wires and better sensing problems on the grid than the system they replace, may help to better improve the ability to "see" what is happening on the grid.
Advances in distributed generation, like home solar panels, both assist and are assisted by the creation of the smart grid. The load production is closer to where it is needed and can help balance peak load needs.47
So, those who control the grid are largely the Independent System Operators (ISOs) or Regional Transmission Organizations (RTOs) which were created by FERC. They tend to run the grid in several states or in large states, and work to constantly coordinate and monitor supply and demand.48 The realm in which FERC has been allowed to exercise broader power is in the creation and enforcement of reliability standards. After the 2003 blackout, an act of Congress (EPACT05) allowed FERC to designate an organization to control reliability standards. FERC selected the renamed North American Electric Reliability Organziation (NERC) to take on this role. NERC has designated some of its reliability functions, however, to its eight reliability regions.49
To the average consumer, there may seem to be little to argue about. An interconnected grid allows for reliable, reasonably priced power, and can make it possible to make more and better use of alternative energy sources. Yet, people do argue, a lot, about siting new transmission lines, and, increasingly, about whether new transmission lines are even necessary.
The argument ends up being somewhat complex, as there are a variety of different issues around which to focus decisions: 50
- Should the focus of improving the grid be on making more renewable energy possible or on minimizing the transmission congestion which can lead to blackouts?
- Who should make the decisions? FERC? Local/regional transmission organizations? Each of the Interconnects? If the latter, who is in charge, since in the Eastern Interconnect there are multiple subregional entities with transmission authority?
- Should the decisions be about where to build new lines? Or more broadly about solutions to transmission problems, including "demand response" which allows energy users to be cut off from power during extremely high demand moments.
- How do we ensure that any changes fairly include input from all producers and transmission authorities?
All want to make the best possible grid, but a certain perspective on what is "best" can greatly skew the argument. For example, some suggested solutions for the congested northeastern U.S. focused on increasing available power, while ensuring that the maximum use was made of renewable power sources. As a result, it was suggested that "massive transmission construction to bring wind power from the Dakotas to the East Coast" was necessary. The northeastern regional transmission organizations (RTOs) pointed out the need to consider possibilities like demand response and closer Canadian renewables.51
As projects in Washington State's Olympic Peninsula have shown, real-time price information transmitted to consumers with automated control systems, combined with "grid-friendly appliances" that are equipped to shut themselves down temporarily when the grid overloads, can substantially reduce the need for new transmission infrastructure. The consumer response system decreased peak transmission loads by half for days at a time, and customers decreased their energy bills by 10 percent.52 If such systems can address peak demand, new transmission lines become unnecessary until further into the future, if needed at all.
Much of the uncertainty about how to resolve problems in the grid revolves around the more recent changes in energy markets. Increased use of wind energy generation means more variable power supplies that have to be backed up by storage or by other power generation systems. Demand response for both large and small consumers is becoming an increasingly viable way to deal with peak energy use. More and more grid customers are contributing to the grid with "distributed generation," in which both home and industrial customers produce some or all of their own power.53 These and other changes make adapting the grid an increasingly complex proposition, but also allow for more flexible options for the future of electricity production, transmission and distribution.
To Learn More
The basics on transmission, especially from a policy point of view:
Brown, M.H. and R.P. Sedano. "Electricity Transmission: A Primer." National Council on Electricity Policy, 2004. Available from http://www.ncouncil.org.
A concise timeline of the grid:
Smartgrid.gov. "Electric Grid History." Office of Electricity Delivery & Energy Reliability, U.S. Department of Energy. http://www.smartgrid.gov/about/smart_grid_history.
A straightforward description of transformers:
California Energy Commission. "How Does a Transformer Work?" http://www.energyquest.ca.gov/how_it_works/transformer.html.
If you want to get into the engineering nitty-gritty, this is a good one:
Miller, R.H. and J.H. Malinowski. Power System Operation, 3rd Edition. Boston, MA: McGraw Hill, 1994.
A very nice set of photos that illustrates the parts of the grid system:
OSHA. "Electric Power eTool: Illustrated Glossary: Substations." http://www.osha.gov/SLTC/etools/electric_power/illustrated_glossary/substation.html.
ABB. "The Western USA Interconnection (Pacific Intertie)." 2009. http://www.abb.com/cawp/gad02181/25d976c493ca472dc125766a0045818a.aspx.
Bonneville Power Administration (BPA). "Factsheet: Celilo Converter Station." 2005. http://www.bpa.gov/corporate/pubs/fact_sheets/05fs/fs1005b.pdf.
Brown, M.H. and R.P. Sedano. "Electricity Transmission: A Primer." National Council on Electricity Policy, 2004. Available from http://www.ncouncil.org.
California Energy Commission, "How Things Work: How Does a Transformer Work?", California Energy Commission, April 22, 2002. http://www.energyquest.ca.gov/how_it_works/transformer.html (Accessed March 15, 2010).
Eaton, J.R. and Cohen, E. Electric Power Transmission Systems, 2nd Edition. Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1983.
ERCOT. "History." Electric Reliability Council of Texas, 2010. http://www.ercot.com/about/profile/history/.
Kaplan, S.M. "Electric Power Transmission: Background and Policy Issues." Congressional Research Service Report for Congress, April 14, 2009.
Kline, Ronald R. Consumers in the Country: Technology and Social Change in Rural America. Baltimore, MD: The Johns Hopkins University Press, 2002.
Koerner, Brendan I. "Why Texas Has Its Own Power Grid." Slate.com, August 19, 2003. http://www.slate.com/id/2087133/.
McGraw, Thomas K. TVA and the Power Fight, 1933-1939.
Miller, R.H. and J.H. Malinowski. Power System Operation, 3rd Edition. Boston, MA: McGraw Hill, 1994.
Minkel, JR. "The 2003 Northeast blackout: five years later." Scientific American, August 13, 2008. http://www.scientificamerican.com/article.cfm?id=2003-blackout-five-years-later&page=2 (Accessed March 26, 2010).
Miras, J.C. "The Advantages of DC Transmission over AC Transmission Systems." Jcmiras.Net_01: Internet, Programming and Power Engineering, August 4, 2006. http://www.jcmiras.net/jcm/item/86/ (Accessed March 15, 2010).
National Institute of Environmental and Health Sciences (NIEHS). "Electric and Magnetic Fields." NIEHS - National Institutes of Health. http://www.niehs.nih.gov/health/topics/agents/emf/ (accessed March 27, 2010).
Niles, Raymond C. "Property Rights and the Crisis of the Electric Grid." Columbia International Affairs Online: Journals 3(2) 2009.
North American Electric Reliability Corporation (NERC). "2009 Summer Reliability Assessment," North American Electric Reliability Corporation, May 2009. http://www.nerc.com/page.php?cid=4|61 (Accessed March 26, 2010).
O'Grady, E. "Loss of Wind Causes Texas Power Grid Emergency." Reuters, February 27, 2008. http://www.reuters.com/article/idUSN2749522920080228 (accessed March 26, 2010).
OSHA. "Electric Power eTool: Illustrated Glossary: Substations." (n.d.). http://www.osha.gov/SLTC/etools/electric_power/illustrated_glossary/substation.html Accessed March 15, 2010.
Pacific Northwest National Laboratory (PNNL). "GridWise Demonstration Project Fast Facts." Richland, WA: Pacific Northwest National Laboratory, December 2007. Available from http://www.pnnl.gov.
Platt, Harold L. The Electric City: Energy and the Growth of the Chicago Area, 1880-1930. Chicago, IL: University of Chicago Press, 1991.
Sparrow, J., J. Summers, T. Vuong and J. Cheng. "Events/1965: Great Northeast Blackout." Fairfax, VA: George Mason University, The Blackout History Project. http://blackout.gmu.edu/events/tl1965.html. Accessed March 26, 2010.
U.S. Dept. of Energy/Litos Strategic Communication. The Smart Grid: An Introduction. Available at http://www.oe.energy.gov/smartgrid.htm. No date.
Alternating current (AC): electric flow which changes its voltage frequently and cyclically between positive and negative (60 times per second in the U.S.). This is the kind of current used to transmit most of our electricity over long distances and which is transformed and used in homes and businesses. It is easily transformed from high voltages that carry power more efficiently to low voltages that are safer for human use.54
Demand response: a smart grid-related solution to a lack of energy in a transmission system. High energy users, from industrial users to high energy appliances like clothes dryers, can be cut off from energy during brief periods of high energy demand.
Direct current (DC): electric flow which is continuous through wires or transmission lines. There is no change in the voltage charge. This kind of current is found in battery operated devices and in some long-distance, extra-high voltage transmission lines.
Distributed generation: power production on a more localized model than is currently common. Includes such production as home solar panels and wind turbines.
Electric Grid: a network of synchronized power providers and consumers that are connected by transmission and distribution lines and operated by one or more control centers
Federal Energy Regulatory Commission (FERC): The U.S. federal entity charged with supervising and controlling power production and creation of new power infrastructure in the U.S. It has limited powers, with many permitting and control functions devolving to states, the utilities, or transmission organizations.
Interties: connectors between regional electric grids. They can be both alternating current and direct current connections, and are usually meant to allow power to flow to where it is most needed.
NIMBY (not in my backyard): a policy-driving sentiment of citizens who desire to prevent new infrastructure or pollution from affecting their local neighborhoods.
Peak (transmission) demand: the period of each day when electrical usage is highest. It is sometimes tied to such moments as the hottest part of a summer day (when air conditioners are turned up high). Often, special generation facilities are designated to be brought online (into grid use) just for peak demand. In theory, the interconnected grid helps decrease the need for such facilities.
Peaker plants: power generation plants that are used specifically to meet the needs of extra high peak demand moments (as in the hottest part of the summer). Often used to a very limited extent and usually use fossil fuels
1 Declared by the National Academy of Engineering at the start of the 21st century as "the single most important engineering achievement of the 20th century." In: U.S. Dept. of Energy/Litos Strategic Communication. The Smart Grid: An Introduction, n.d., 5
2 Lewis Barbier, "The United States at Night," Exploration of the Universe Division, Goddard Space Flight Center, NASA, January 18, 2003. Retrieved May 5, 2010 from http://nightglow.gsfc.nasa.gov/states_night.html.
3 Mathew H. Brown and Richard P. Sedano, Electricity Transmission: A Primer, (National Council on Electricity Policy, 2004: http://www.ncouncil.org), 36,37.
4 Figure and text: Stutz, Michael. "Direct vs alternating current." "What is alternating current?" 1999-2000. http://www.allaboutcircuits.com/vol_2/chpt_1/1.html.
5 Mathew H. Brown and Richard P. Sedano, Electricity Transmission: A Primer, (National Council on Electricity Policy, 2004: http://www.ncouncil.org),10.
6 Mathew H. Brown and Richard P. Sedano, Electricity Transmission: A Primer, (National Council on Electricity Policy, 2004: http://www.ncouncil.org), 8-11.
7 J. R. Minkel, "The 2003 Northeast Blackout--Five Years Later," (New York: Scientific American, August 13, 2008: http://www.scientificamerican.com/article.cfm?id=2003-blackout-five-years-later).
8 James T. Sparrow et al., "Great Northeast Blackout," (The Blackout History Project, June 27, 2000: http://blackout.gmu.edu/events/tl1965.html).
9 NERC, "2009 Summer Reliability Assessment," North American Electric Reliability Corporation, May 2009. Retrieved March 27, 2010 through: http://www.nerc.com/page.php?cid=4|61.
10 Robert H. Miller and James H. Malinowski, Power System Operation, 3rd Edition, (Boston, MA: McGraw Hill 1994), 63.
11 ABB. "The Western USA Interconnection (Pacific Intertie)." 2009. http://www.abb.com/cawp/gad02181/25d976c493ca472dc125766a0045818a.aspx and Bonneville Power Administration (BPA). "Factsheet: Celilo Converter Station." 2005. http://www.bpa.gov/corporate/pubs/fact_sheets/05fs/fs1005b.pdf.
12 Eileen O'Grady, "Loss of Wind Causes Texas Power Grid Emergency," Reuters, February 27, 2008, accessed online at http://www.reuters.com/article/idUSN2749522920080228.
13 Stan Mark Kaplan, "Electric Power Transmission: Background and Policy Issues," Congressional Research Service Report for Congress, April 14, 2009, 33.
14 ERCOT. "History." Electric Reliability Council of Texas, 2010. http://www.ercot.com/about/profile/history/ and Koerner, Brendan I. "Why Texas Has Its Own Power Grid." Slate.com, August 19, 2003. http://www.slate.com/id/2087133/.
15 Robert H. Miller and James H. Malinowski, Power System Operation, 3rd Edition, (Boston, MA: McGraw Hill 1994), 12-19. Mathew H. Brown and Richard P. Sedano, Electricity Transmission: A Primer, (National Council on Electricity Policy, 2004: http://www.ncouncil.org), 35.
16 JC Miras, "The Advantages of DC Transmission over AC Transmission Systems" Jcmiras.Net_01: Internet, Programming and Power Engineering, August 4, 2006. Retrieved March 15, 2010, from http://www.jcmiras.net/jcm/item/86/.
17 Robert H. Miller and James H. Malinowski, Power System Operation, 3rd Edition, (Boston, MA: McGraw Hill 1994), 232.
18 Following descriptions based on: OSHA, "Electric Power eTool: Illustrated Glossary: Substations," (n.d.). Retrieved March 15, 2010, from http://www.osha.gov/SLTC/etools/electric_power/illustrated_glossary/substation.html.
19 Karora, "Haywards electrical substation," Wikimedia Commons, September 19, 2004: http://commons.wikimedia.org/wiki/File:Haywards_Electrical_Substation.jpg.
20 Nixdorf, "Electric transmission lines," Wikimedia Commons, July 14, 2004: http://en.wikipedia.org/wiki/File:Electric_transmission_lines.jpg.
21 California Energy Commission, "How Things Work: How Does a Transformer Work?", California Energy Commission, April 22, 2002. Retrieved March 15, 2010 from http://www.energyquest.ca.gov/how_it_works/transformer.html.
22 "Polemount Transformer," Wikimedia Commons, September 11, 2004: http://en.wikipedia.org/wiki/File:Polemount-singlephase-closeup.jpg.
23 Robert H. Miller and James H. Malinowski, Power System Operation, 3rd Edition, (Boston, MA: McGraw Hill 1994), 24-25.
24 California Energy Commission, "How Things Work: How Does a Transformer Work?", California Energy Commission, April 22, 2002. Retrieved March 15, 2010 from http://www.energyquest.ca.gov/how_it_works/transformer.html.
25 Harold L. Platt, The Electric City: Energy and the Growth of the Chicago Area, 1880-1930, Chicago, IL: University of Chicago Press 1991, xv.
26 Harold L. Platt, The Electric City: Energy and the Growth of the Chicago Area, 1880-1930, Chicago, IL: University of Chicago Press 1991, xv.
27 Harold L. Platt, The Electric City: Energy and the Growth of the Chicago Area, 1880-1930, Chicago, IL: University of Chicago Press 1991, 23-24.
28 Raymond C. Niles. "Property Rights and the Crisis of the Electric Grid." Columbia International Affairs Online: Journals 3(2) (2009).
29 Harold L. Platt, The Electric City: Energy and the Growth of the Chicago Area, 1880-1930, Chicago, IL: University of Chicago Press 1991, 39.
30 Harold L. Platt, The Electric City: Energy and the Growth of the Chicago Area, 1880-1930, Chicago, IL: University of Chicago Press 1991, 84-85.
31 Richard Freeman. "How Roosevelt's RFC Revived Economic Growth, 1933-45" Economic Intelligence Review 33(11), March 17, 2006.
32 WhatIs.com. "Electric grid." "The Tech Dictionary and IT Encyclopedia." TechTarget, 2008. http://whatis.techtarget.com/whome/0,289825,sid9,00.html
33 Smartgrid.gov. "Electric Grid History," (Office of Electricity Delivery & Energy Reliability, U.S. Department of Energy, 2010: http://www.smartgrid.gov/about/smart_grid_history).
34 Ronald R. Kline Consumers in the Country: Technology and Social Change in Rural America. Baltimore, MD: The Johns Hopkins University Press 2002, 3.
35 Ronald R. Kline Consumers in the Country: Technology and Social Change in Rural America. Baltimore, MD: The Johns Hopkins University Press 2002, 3-5.
36 U.S. Department of Agriculture. Rural Electrification Administration. "Brief History of the Rural Electrification and Telephone Programs," April 18, 1982 (accessed at http://www.rurdev.usda.gov/rd/70th/rea-history.pdf).
37 Smartgrid.gov. "Electric Grid History," Office of Electricity Delivery & Energy Reliability, U.S. Department of Energy, 2010: http://www.smartgrid.gov/about/smart_grid_history.
38 Tverberg, G. E. "The U.S. electric grid: will it be our undoing?" The Oil Drum, May 7, 2008: http://www.theoildrum.com/node/3934.
39 Tverberg, G. E. "The U.S. electric grid: will it be our undoing?" The Oil Drum, May 7, 2008: http://www.theoildrum.com/node/3934.
40 U.S. Federal Regulatory Commission. "Regional Transmission Organizations." Docket No. RM99-2-001; Order No. 2000-A, February 25, 2000: http://www.ferc.gov/legal/maj-ord-reg/land-docs/2000A.pdf.
41 Egan, Timothy. "Tapes Show Enron Arranged Plant Shutdown." The New York Times, February 4, 2005: http://www.nytimes.com/2005/02/04/national/04energy.html?_r=1&ex=1107666000&en=01449ebf62df572e&ei=5070.
42 California Electric and Magnetic Fields Program. "Electric and Magnetic Fields: measurements and possible effect on human health — what we know and what we don't know in 2000," (California Department of Health Services and the Public Health Institute, December 2000: http://www.ehib.org/emf/).
43 Mathew H. Brown and Richard P. Sedano, Electricity Transmission: A Primer, (National Council on Electricity Policy, 2004: http://www.ncouncil.org), 22-23.
44 Stan Mark Kaplan, "Electric Power Transmission: Background and Policy Issues," Congressional Research Service Report for Congress, April 14, 2009, 5-6.
45 Stan Mark Kaplan, "Electric Power Transmission: Background and Policy Issues," Congressional Research Service Report for Congress, April 14, 2009, 6.
46 Stan Mark Kaplan, "Electric Power Transmission: Background and Policy Issues," Congressional Research Service Report for Congress, April 14, 2009, 6-7.
47 U.S. Dept. of Energy/Litos Strategic Communication. The Smart Grid: An Introduction. Available at http://www.oe.energy.gov/smartgrid.htm. No date.
48 U.S. Dept. of Energy/Litos Strategic Communication. The Smart Grid: An Introduction, n.d., 12.
49 Points drawn directly from: Stan Mark Kaplan, "Electric Power Transmission: Background and Policy Issues," Congressional Research Service Report for Congress, April 14, 2009, 8-9.
50 Points drawn directly from: Stan Mark Kaplan, "Electric Power Transmission: Background and Policy Issues," Congressional Research Service Report for Congress, April 14, 2009, 14.
51 Stan Mark Kaplan, "Electric Power Transmission: Background and Policy Issues," Congressional Research Service Report for Congress, April 14, 2009, 12.
52 Pacific Northwest National Laboratory (PNNL). "GridWise Demonstration Project Fast Facts." Richland, WA: Pacific Northwest National Laboratory, December 2007. Available from http://www.pnnl.gov
53 Stan Mark Kaplan, "Electric Power Transmission: Background and Policy Issues," Congressional Research Service Report for Congress, April 14, 2009, 32-33.
54 J. Robert Eaton and Edwin Cohen, Electric Power Transmission Systems, 2nd Edition, (Englewood Cliffs, N.J.: Prentice-Hall, Inc., 1983), 3.