Experts say the cascading blackout that put millions of Westerners in the dark last week was no surprise: Major power outages have more than doubled in the last decade.

"This is just evidence that we need a smarter, better, more secure system," said Massoud Amin, director of the Technological Leadership Institute at the University of Minnesota, who has analyzed federal data on the reliability of the nation's electric grid.

Blackouts disrupt power to at least a third of U.S. homes each year, and studies show the number of outages is rising.

The grid's shortcomings have been well-documented, but efforts to modernize it haven't kept up with demand. Many electrical transmission lines are outdated, and parts of the grid date back to the time of Thomas Edison.

The chairman of the Federal Energy Regulatory Commission, which oversees the nation's grid, acknowledged increasing problems with the system.

In a July interview with ProPublica, FERC Chairman Jon Wellinghoff said that while the electric grid is reliable, it is degrading. "It's not getting better," he said. "It's getting worse."

Many experts say smart-grid technology would help. Such a system would be able to intelligently respond to sudden peaks or drops in demand and energy supply.

Last week, for example, a mishap involving a single worker doing repairs on a power station near Yuma, Ariz., led to rolling blackouts over parts of Arizona, Southern California and Northern Mexico. The short circuit caused San Diego County's power-supply system to completely shut down after it was required to take on the demand of those affected in Arizona and buckled under the extra load.

Had a smart grid been in place, it might have helped isolate the outage and prevent it from spreading. By monitoring activity on transmission lines in real time, a smart grid also can help pinpoint a problem and redirect power accordingly.

The Obama administration has allocated $11 billion in stimulus funding toward the electric grid. Of that, $4.4 billion was dedicated directly to building a smart grid. But the money will take years working its way through the bureaucratic pipeline; so far, only $1.4 billion has been spent.

Experts also say smart grids are only part of the solution and that transmission lines also have to be built.

"These are essential facilities. They are like highways, they are like airports—everyone relies on them," former FERC Chairman Jim Hoecker said.

But transmission lines cost money, and utilities say investing too much more in infrastructure will cost consumers. According to David Owens, executive vice president for business operations at Edison Electric Institute, transmission costs make up 35 percent to 40 percent of a typical homeowner's energy bill. Shareholder-owned utilities will invest $11.2 billion in transmission in 2011—almost twice as much as in 2004. The increase pushes the envelope on what customers are willing to pay, Owens said.

Wellinghoff, FERC's current chairman, said the commission also needs broader authority to oversee transmission lines. That would require congressional approval.

One project that might benefit from broader FERC power is the Susquehanna-Roseland power line. The line, which would run from Pennsylvania to Northern New Jersey, has been delayed for two years because a four-mile stretch passes through a national park. Although the line would follow the same path as a pre-existing line, the National Park Service has blocked construction to analyze the effect of the line on the environment. Wellinghoff said FERC's engineers had already done an environmental review.

Absent new transmission lines and a smart grid, large blackouts could become more common.

Last week's massive outage echoed a blackout eight years ago. In 2003, a power surge on a transmission line that circles Lake Erie left dozens of cities in the East and Canada without power, shutting down 21 power plants in just three minutes.

After the power came back on, politicians, regulators and industry officials all pledged to push for a more reliable, modern grid.

But the promises did not translate into action.

"We have overharvested the infrastructure," Amin said. "We aren't milking the cow dry; we already have milked the cow dry. It has gotten to the point where there are many choke points. We cannot just sit and watch the load increase."