For a commodity we take for granted, electricity is remarkably challenging to deliver. The national grid that sends electrons to our computers and toasters is, in essence, one huge electrical circuit. The laws of physics dictate that supply and demand must stay in exquisite balance, like a ballerina endlessly pirouetting en pointe. If one transmission line fails, the system must instantaneously reroute power or other lines and power plants will fall like so many dominoes, causing massive blackouts.
The surprise is that the unsung managers of the grid successfully maintain this delicate balance virtually all the time, using automation and their own judgment to keep electricity flowing amid storms, floods, and power-plant crashes. Indeed, problems like those suffered by power lines in Ohio, which may have led to the Aug. 14 blackout, are solved constantly every day on the grid. "This blackout should not have occurred," says William Massey, a commissioner at the Federal Energy Regulatory Commission (FERC). "There was a system failure."
The reasons for the failure -- and why some areas of the country, such as New England, did cope -- are still unknown. But to those who understand the vulnerabilities of the electricity grid, there's no mystery about the steps that now need to be taken to reduce the chances of future blackouts. They have a vision of a technologically advanced digital system with enough smarts to manage this fragile balance on its own. Here's what we need to get there:
Tough, Uniform Standards
Today's electricity system is a complicated patchwork of hundreds of power plants and thousands of miles of transmission lines, divided up into scores of different control areas, each run by different authorities. After the blackout of 1965, the North American Electric Reliability Council (NERC) was created to set standards and rules for key technical details, such as how precisely the quality of the electric current must be controlled, or how much transmission capacity must be held in reserve. But the standards are voluntary and are not always met. "The incentive to cheat is universal," says Ralph Cavanagh, co-director of the Natural Resources Defense Council's energy program. That can lead to problems when electrons flow across the seams between regions using different rules. There's a simple, inexpensive solution to this: mandatory national standards, with NERC cops on the beat to enforce them.
Rapid surges or drops in power can burn out transmission lines and wreak havoc at power plants. That's why each component is protected by relays -- essentially, circuit breakers -- that open to remove the line or plant from the grid. The problem is that there's no communication between the various parts of the grid. "There is no way for one system operator to know the details of what's going on in other areas," says Marija D. Ilic, professor of electrical and computer engineering at Carnegie Mellon University. Ilic and others have developed software that looks across seams of the grid and better manages the overall flow of electricity.
Faster Digital Switches
Imagine how hard it would be to ship freight on the railroads if it took 10 days to open and close a switch. That's how slow the current mechanical switches are on the electricity grid relative to the speed of electrons, says Kurt E. Yeager, president of the Electric Power Research Institute. As a result, there is always a split-second delay in responding to problems -- which in some instances could be too long. That's why a consortium organized by EPRI is developing digital switches that operate at the speed of light, along with sensors capable of spotting disturbances instantly. With the new technology, the grid would be smart enough to react to problems before they spread. "The key is to make the grid self-healing," says Bruce Germano, vice-president of Long Island Power Authority.
Adding more transmission lines also helps. But the new technology can make far better use of existing wires. A substation in New York is being outfitted with the new digital switches, and it will pass along nearly 200 megawatts more power than before. Adding digital smarts is one of the big-ticket items in upgrading the grid. The cost is pegged at $50 billion to $100 billion over 5 to 10 years. But that's a bargain, experts say, since routine outages alone cost the economy an estimated $100 billion a year.
The grid operates on alternating current -- the same frequency of 60 cycles per second as the stuff that comes out of your wall plug. This makes managing the grid more difficult since small frequency fluctuations on the grid can damage equipment elsewhere. But if the AC power generators were isolated from each other using high-voltage direct-current links, there would be less need to synchronize frequencies. "The grid would be less likely to go out," explains Sarosh Talukdar, professor of electrical and computer engineering at Carnegie Mellon University. A few such links, including an 846-mile line between the Pacific Northwest and Los Angeles, have been built. EPRI's Yeager also envisions small direct-current minigrids to deliver higher-quality power to industrial parks, office towers, or residences.
Distributed Sources of Power
If subway systems, hospitals, factories, office buildings, and even homes had their own power sources, blackouts would be far less disrupting. And these small generators -- everything from solar panels and windmills to diesel-powered facilities and small turbines -- could feed their excess electricity into the grid, reducing the need for new power plants and transmission lines. "In my lifetime, there's going to be a paradigm shift to distributed resources," predicts Shalom Zelingher, director of research and technology development at the New York Power Authority. One reason Zelingher and most other energy experts are sanguine: So-called distributed power schemes can save money, especially when generators are attached to the grid. Companies with their own power sources can use the cheapest electricity -- theirs or the grid's -- and also sell excess power back to the system.
Paradoxically, however, attaching many small power sources to the grid increases the potential for problems, since the intermittent electricity generated by these sources would be "just another vehicle to upset the delicate balance of the system," says Yeager. Therefore, a grid smart enough to handle the added complexity must be created first.
Once electricity experts figure out the precise causes of the Aug. 14 blackout, they will be able to make immediate fixes to prevent the same chain of events from recurring. And the $100 billion investment to create the smart digital grid will slash even further the chances of massive blackouts, as well as routine outages.
Of course, technology will never make the system completely fail-safe. "There is no way of guaranteeing that complicated systems will never go down," says Carnegie Mellon University economist Lester B. Lave. But taking these steps will reduce the odds that the lights go out again anytime soon.
By John Carey in Washington, with Adam Aston in New York