Electric Grid Overview

Posted on April 23, 2014 by

[ Our energy, transportation, electric, water and other infrastructures are all heavily dependent on each other, making the U.S. one of the most vulnerable nations on earth.  Although transportation is the most essential of all, especially trucks, which make the electric grid and electricity generation contraptions possible from mining to manufacture to thousands of components delivered via world-wide supply chains to final delivery to the site, electricity outages can take down transportation (i.e. gas pumps are electric, etc).

To understand why, it helps to learn how the electric grid works, which I’ve attempted to do below.

Alice Friedemann   www.energyskeptic.com  author of “When Trucks Stop Running: Energy and the Future of Transportation”, 2015, Springer and “Crunch! Whole Grain Artisan Chips and Crackers”. Podcasts: Practical Prepping, KunstlerCast 253, KunstlerCast278, Peak Prosperity , XX2 report ]

Electricity is essential.

In a blackout all of these essential services fail: Pumping of potable water, sewage, and irrigation water; sewage treatment; food and fuel supply and storage; refrigeration; medical facilities, prisons, banking, communications, refineries, shipping, transportation, commerce, and home/commercial life-support systems (heating, ventilation, and air conditioning), etc.

Modern life is impossible without it.

Electric power transmission and distribution (T&D) in the United States is in urgent need of expansion and upgrading.  It’s been called the world’s largest machine run by over 3,100 utility companies, with nearly 3,000 power plants that generate 4.16 million GWh.  Fossil fuels generated 70% of the electricity — 49% coal and 21% natural gas.  Renewable energy only contributed 8.4%, with 6% of that from hydropower.

The American Society of Civil Engineers has warned that without an investment of $100 billion, the US power generation system will collapse by 2020. Growing loads, aging equipment, and wind and solar power are destabilizing and stressing the system, which increases the risk of widespread blackouts. Modern society depends on reliable and economic delivery of electricity.

Recent concerns have stemmed from inadequate investment to meet growing demand, the limited ability of those systems to accommodate renewable-energy sources that generate electricity intermittently, and vulnerability to major blackouts involving cascading failures.  And also, distant sources of renewable generation can’t be used without expanding the grid.

The high-voltage transmission system (or grid) transmits electric power from generation plants through 163,000 miles of high-voltage (230 kilovolts [kV] up to 765 kV) electrical conductors and more than 15,000 transmission substations. The transmission system is configured as a network, meaning that power has multiple paths to follow from the generator to the distribution substation.

The distribution system contains millions of miles of lower-voltage electrical conductors that receive power from the grid at distribution substations. The power is then delivered to 131 million customers via the distribution system. In contrast to the transmission system, the distribution system usually is radial, meaning that there is only one path from the distribution substation to a given consumer.

Problems with the Current System

Most U.S. transmission lines and substations were constructed more than 40 years ago and are based on 1950s’ technology, but demands on the electric power system have increased significantly over the years. Since 1990, electricity generation has risen from about 3 trillion kilowatt-hours (kWh) to about 4 trillion in 2007. Long-distance transmission has grown even faster for reliability and economic reasons, including new competitive wholesale markets for electricity, but few new transmission lines have been built to handle this growth.

From 1985 through 1995, transmission investment was fairly stable at the level of about $4.5 billion per year. In the late 1990s, the restructuring and re-regulation of the U.S. transmission system led to a decrease in investment down to about $3 billion a year and is operating at or near its physical limits often.

Inadequate system maintenance and repair also have contributed to an increase in the likelihood of major transmission system failures.  Of greatest concern is the risk of these disturbances cascading over large portions of the T&D systems. The 2003 blackouts in the world’s two largest grids—the North American Eastern Interconnection and the West European Interconnection—resulted from such cascading failures. Each event affected 50 million people.

If the electric grid comes down from cyber or nuclear war, an Electromagnetic pulse, natural gas shortages (natural gas peaker plants are essential to balancing “renewable” energy), coal shortages, terrorist attacks, natural disasters, oil shocks, and so on, the electric grid could be down for a year or more in one or all of the regional networks.

Anyone who hopes that renewable energy could compensate even slightly for oil in the future needs to understand that above all, there has to be a 100% reliable and vastly expanded electric grid. Yet The Grid is rusting and falling apart right now for many reasons.  One of them is deregulation, which has made it unprofitable to maintain The Grid because it harms the profits of the shareholders.

There’s no point in building wind, solar, hydro, and nuclear power plants without a robust and expanded electric power grid.  And without the electric grid, it will be hard to make microchips and other gadgets essential to civilization, there will be no refrigeration, lights, electrified transportation, hospital services, internet, computers running — we are as dependent on the electric grid as we are on oil.  A decentralized system is not capable of making steel, aluminum, make cement, and all the other heavy duty chores needed to maintain civilization as we know it.

A quick way to get up to speed on this topic are the following:

I think the grid is fascinating, an immense puzzle, the world’s largest machine – I hope you’ll read these and other books to really grasp the immensity, complexity, and vulnerability of the grid.

Grid Stability

Blackouts happen when there’s too much or too little power and the frequency deviates too much from the very narrow band of 60 Hz frequency – a great explanation of this is:

Chris Lee. March 13, 2013. Stabilizing the electric grid by keeping generators in sync Better grid design should keep generators from fluctuating in phase. Nature Physics, 2013. DOI: 10.1038/nphys2535

Los Angeles Times: Green energy is making collapse of the electric grid more likely

Evan Halper. Dec 2, 2013.   Power struggle: Green energy versus a grid that’s not ready. Minders of a fragile national power grid say the rush to renewable energy might actually make it harder to keep the lights on.  Los Angeles Times.

The grid is also built on an antiquated tangle of market rules, operational formulas and business models.  Planners are struggling to plot where and when to deploy solar panels, wind turbines and hydrogen fuel cells without knowing whether regulators will approve the transmission lines to support them.

Energy officials worry a lot these days about the stability of the massive patchwork of wires, substations and algorithms that keeps electricity flowing. They rattle off several scenarios that could lead to a collapse of the power grid — a well-executed cyberattack, a freak storm, sabotage.

But as states, led by California, race to bring more wind, solar and geothermal power online, those and other forms of alternative energy have become a new source of anxiety. The problem is that renewable energy adds unprecedented levels of stress to a grid designed for the previous century.

Green energy is the least predictable kind. Nobody can say for certain when the wind will blow or the sun will shine. A field of solar panels might be cranking out huge amounts of energy one minute and a tiny amount the next if a thick cloud arrives. In many cases, renewable resources exist where transmission lines don’t.

“The grid was not built for renewables,” said Trieu Mai, senior analyst at the National Renewable Energy Laboratory.

The role of the grid is to keep the supply of power steady and predictable.

Engineers carefully calibrate how much juice to feed into the system as everything from porch lights to factory machines are switched on and off. The balancing requires painstaking precision. A momentary overload can crash the system.

California has taken some of the earliest steps to address the problems. The California Public Utilities Commission last month ordered large power companies to invest heavily in efforts to develop storage technologies that could bottle up wind and solar power, allowing the energy to be distributed more evenly over time.

Whether those technologies will ever be economically viable on a large scale is hotly debated.

Already, power grid operators in some states have had to dump energy produced by wind turbines on blustery days because regional power systems had no room for it. Officials at the California Independent System Operator, which manages the grid in California, say renewable energy producers are making the juggling act increasingly complex.

“We are getting to the point where we will have to pay people not to produce power,” said Long Beach Mayor Bob Foster, a system operator board member.

Joel Brenner.  2011. “America the Vulnerable: Inside the New Threat Matrix of Digital Espionage, Crime, and Warfare”.

Electric grid Vulnerability

Retired military officers wrote a 62 page report called “Powering America’s Defense: Energy and the Risks to National Security”.   The report discusses the U.S. electric grid, which it says is “unnecessarily vulnerable.”

The grid is very vulnerable to cyber attacks as explained in my two book reviews of:

  1. Richard Clarke. 2012. CYBER WAR. The Next Threat to National Security and What to Do About It”.
  2. Joel Brenner.  2011. “America the Vulnerable: Inside the New Threat Matrix of Digital Espionage, Crime, and Warfare”.

Also  see:

Emergency drill: Cyberattack on electric grid

Assault on California Power Station Raises Alarm on Potential for Terrorism. April Sniper Attack Knocked Out Substation, Raises Concern for Country’s Power Grid (Wall Street Journal). New York Times: Sniper Attack at power hub still a mystery

Philip Ball. Jan 2004. Power blackouts likely: Electricity systems are becoming ever more vulnerable, and there’s no quick fix.  Nature.   Geomagnetic storms could cause large blackouts in the future, and the way the grid is growing makes it more vulnerable, according to John Kapperman, a government advisor.  The Sun ejects streams of charged particles that can warp the Earth’s magnetic field, producing dazzling atmospheric effects such as the aurora borealis. The changing magnetic field also induces a direct current in transformers. This causes huge electrical surges, because the grid is meant to take only alternating current. “It’s very difficult to design a transformer that can cope with this,” says Kappenman. The effect on power grids can be devastating. In 1989, the power grid in Quebec, Canada, was shut down within 90 seconds of a major geomagnetic storm. As the grid grows, and more interconnecting wires are added to the system, it actually becomes more vulnerable to such storms. Over the past 50 years, there has been a tenfold increase in the lengths of power lines in the United States. “The power companies have unwittingly built risks into the grid, and the risk is spiralling out of control,” he says.

H. Byrd. 12 May 2014. Lights out: The dark future of electric power. NewScientist.com

We predict that blackouts will occur with greater frequency and greater severity due to trends in both electricity supply and demand. Supply will become increasingly precarious because of the depletion of fossil fuels, neglected infrastructure and the shift toward less reliable renewable energy. Demand, meanwhile, will grow because of rising populations and affluence.

Resource depletion is already having an effect on countries that rely on fossil fuels such as coal for electricity generation. Countries with significant renewable resources are not immune either. Weather is not predictable and is likely to become less so, courtesy of climate change: in the past decade shortages of rain for hydro dams has led to blackouts in Kenya, India, Tanzania and Venezuela.

Deregulation and privatization have created further weaknesses in supply as there is no incentive to maintain or improve the grid. Almost 75% of US transmission lines and power transformers are more than 25 years old and the average age of power plants there is 30 years.

The looming threat of blackouts cannot be solely blamed on vulnerabilities in generation, however. Over-consumption is also a factor. Between 1940 and 2001, average US household electricity use rose 1300 per cent, driven largely by growing demand for air conditioning. And such demand is forecast to grow by 22 per cent in the next two decades.

It is worth reiterating what is at stake here. We analysed almost 50 significant power-outages across 26 countries. They had numerous causes, from technical failure to sabotage. Nonetheless, the same set of problems emerged.

Blackouts affect computers, microprocessors, pumps, fridges, traffic and street lights, security systems, trains and cellphone towers, with consequences across society. The economic losses can be enormous: power outages are already estimated to cost up to $180 billion a year in the US.

GPS pioneer warns on network’s security.   Financial Times.

The Global Positioning System helps power everything from in-car satnavs and smart bombs to bank security and flight control, but its founder has warned that it is more vulnerable to sabotage or disruption than ever before – and politicians and security chiefs are ignoring the risk.

Impairment of the system by hostile foreign governments, cyber criminals – or even regular citizens – has become “a matter of national security”, according to Colonel Bradford Parkinson, who is hailed as the architect of modern navigation.

“If we don’t watch out and we aren’t prepared,” then countries could be denied everything from ‘navigation’ to ‘precision weapon delivery’, Mr Parkinson warned.

“We have to make it more robust … our cellphone towers are timed with GPS. If they lose that time, they lose sync and pretty soon they don’t operate. Our power grid is synchronized with GPS [and] our banking system.”

Western governments are “in their infancy in recognizing the problem”, Mr Parkinson told the Financial Times in an interview on the fringes of a conference for government officials, academics and defense contractors at the UK’s National Physical Laboratory.

He said: “[In the US] I don’t know anyone that is really in charge of it. The Department of Homeland Security should be [but] … they don’t have any people that understand it very well. They’ve got one person without any budget to speak of.”

National Academy of Sciences on why blackouts are a system problem

Jay Apt, et al. Electrical Blackouts: A Systemic Problem Although human error can be the proximate cause of a blackout, the real causes are found much deeper in the power system. issues in Science & Technology. National Academy of Sciences.

Problems at the root of blackouts:

  • Monitoring of the power grid is sparse, and even these limited data are not shared among power companies.
  • Industry standards are lax; for example, vegetation under transmission lines is trimmed only every five years.
  • Operators are not trained routinely with realistic simulations that would enable them to practice dealing with the precursors to cascading failures and the management of large-scale emergencies.
  • Power companies have widely varying levels of equipment, data, and training. Some companies can interrupt power to customers quickly during an emergency, whereas others are nearly helpless.
  • Decades-old recommendations to display data in a form that makes it easy to see the extent of a problem have been ignored. This was a contributing cause of the 1982 West Coast blackout, where “the volume and format in which data were displayed to operators made it difficult to assess the extent of the disturbance and what corrective action should be taken.”
  • Monitoring of the power system is everywhere inadequate, both within regions and between them.

After the passage of the Public Utilities Regulatory Policies Act in 1978 and the Energy Policy Act of 1992, the electricity industry became a hybrid of vertically integrated utilities and new structures of multiple forms. “Merchant generators,” independent of utility companies, installed their own plants and sought customers anywhere in the country. Aggregators bargained for better rates on behalf of large numbers of customers. Energy brokers used the open market and long-term contracts to buy and sell power.

Restructuring has transformed the operation of the electricity system. Utilities formerly transmitted power from a nearby generation plant to customers. Now, industrial customers can buy power from plants hundreds of miles away, putting major burdens on the transmission system and increasing the likelihood of a blackout. That has made a huge difference: The number of times that the transmission grid was unable to transmit power for which a transaction had been contracted jumped from 50 in 1997 to 1,494 in 2002. This metamorphosis has done little to improve the physical system of transmission or its control systems. The burden of making the new system operate reliably has instead fallen on people.

No organization that generates, transmits, or distributes electric power wants low reliability. But in a deregulated competitive electricity market, companies have to pay for investments out of the revenues they earn. Unless companies can find a way to bill customers for reliability, or unless regulators mandate reliability investments and ensure that they are reimbursed, no investments will be made. None of the 19 states that have implemented electric restructuring has figured out how to pay for investments to prevent low-probability events such as blackouts

 

How the Electric Grid Works

National Academy of Science report written for the Department of Homeland Security: “Terrorism and the Electric Power Delivery System. 2012. National Research Council.

As systems became larger and power had to be carried over longer distances, power lines were operated at ever higher voltage in order to minimize losses. Efficient high-voltage transmission lines also made it possible to locate ever larger generators in remote areas rather than close to towns and cities. By the middle of the 20th century, system operators began to connect individual high-voltage systems together so that power could be moved from region to region, both to promote economic efficiency and to increase reliability by making it possible to move power into regions suffering from temporary shortages. Once electric power has been generated, the voltage is stepped up and power moves over long distances through the high-voltage transmission system, a complex network of lines, most of which are carried aboveground on tall towers. At key points throughout this system are substations that contain transformers to increase and decrease the voltage, switching gear that connects the system in desired configurations, and circuit breakers that open and close connections while also acting as giant fuses to protect expensive equipment from damage, as well as a variety of other devices.. When power reaches an area where it will be used, the voltage is reduced and power is distributed to customers over lower-voltage distribution lines. Unlike the transmission system, which is a large interconnected network, many distribution systems branch out radially to deliver power to customers, although some older, dense urban areas, such as New York City, use network configurations for distribution. All the elements of the transmission system, and increasingly those of the distribution system, are monitored and controlled by information and communication systems.

Keeping power flowing to customers is a continuous process of control, recovery, and repair. Most outages are local, brief in duration, and caused by problems at the level of the distribution system—such as lightning strikes, wind storms and tree falls, short circuits caused by wild animals such as squirrels, vehicles that crash into power poles, and similar events. Line crews can usually fix these outages in a matter of hours. Distribution systems that incorporate automation can often isolate a problem and restore service for many affected customers in a matter of seconds or minutes. Outages caused by disruptions in the high-voltage transmission system are less common. When they do occur, because of faulty equipment, weather, or for other reasons, many such outages are never noticed by customers, because automatic controls and system operators can limit their impact and maintain the supply of power to the distribution system. But, of course, the transmission system does occasionally experience problems that result in loss of service to customers. Weather events, such as hurricanes and ice storms, earthquakes, and similar natural events, can bring down many transmission lines, and, less frequently, can damage transformers, circuit breakers, and other equipment such as the terminal facilities for direct-current (DC) lines. Inadequate attention to maintenance can also contribute to blackouts, such as from arcing to vegetation from inadequate tree trimming.

If protection systems are poorly designed or do not operate properly, faults or equipment failures can cause outages and may cascade or propagate into blackouts. Once an overloaded circuit or transformer in the system either fails or is intentionally removed from service, the power flows through other available circuits in proportion to the paths of least resistance. These alternative circuits may in turn become overloaded and either fail or be taken out of service by the protection system. This repeated, possibly uncontrolled, cycle of overload and equipment removal/failure is a dynamic, frequently oscillating phenomenon that can lead to a cascading outage. A local failure can escalate into a cascading failure in a matter of a few minutes, potentially leading to a wide-area blackout.

Structural Changes in the Industry

The electric power industry has undergone considerable changes in the last two decades that have affected how the electricity infrastructure operates. Some of the once vertically integrated electric utilities that supplied generation, transmission, and distribution services have undergone restructuring that separated them into distinct entities with responsibility for only one or a few such services. In 1996, to mandate and facilitate competition at the wholesale level, FERC required transmission-owning utilities to “unbundle” their transmission and power-marketing functions and provide nondiscriminatory, open access to their transmission systems by other utilities and independent power producers. Some utilities pursued unbundling by creating separate divisions within their companies, others spun off certain assets into separate but affiliated companies, and others sold off assets to separate owners (primarily generating facilities). Some states required—or created powerful incentives for—utilities to divest their generation assets as part of a restructuring effort. Others required vertically integrated utilities to divest their transmission assets to independent entities. In addition, power marketers—who often do not own generation, transmission, or distribution facilities—now buy and sell power on wholesale markets and market electricity directly to customers. All of these changes created even greater variations of the operational landscape within the industry. Competition in the electric power industry has led to significant changes in the operation of the system.

The Energy Policy Act of 1992 made it possible for competitive power producers to be entitled to access and use a utility’s transmission system. In some regions, these requirements put new demands on an already stressed power system. In 1996, FERC issued regulatory policies (FERC Orders 888 and 889) that formally required transmission owners to provide open and nondiscriminatory access to the competitive wholesale generation market, and to provide comparable terms and conditions to all market participants, including the generation used to serve a utility’s own customers. FERC policies, in combination with technological and economic changes in the industry, placed extraordinary new demands on transmission systems. Utilities that previously planned and operated their systems for the benefit of their own customers’ requirements were now required to take other market interests into account.

 

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