One of the biggest challenges is just keeping the lights on, literally. It's something we take for granted. Enter a dark room, flick a switch, the light goes on. It's hot, we turn on the air conditioner, and we're refreshed. We really don't think about the power until it goes out. Those of you living in heat stroke parts of the country know that the electricity grid keeping your A/C running is being stressed to the max. Drought-stricken Texas, for instance, has declared several energy emergencies this month, asking consumers to conserve power in order to prevent blackouts. For the most part, the national power grid is stable, but that was not the case eight years ago, when, on August 14, 2003, a million square miles of the Midwest and Northeast experienced the biggest blackout in U.S. history.

[MAN PLAYING SAXOPHONE]

[ASSURAS] 50 million people in eight states and parts of Canada found themselves coping in the dark and stifling August heat for days.

[MAN] We actually have a very serious problem.

[TEXT ON SCREEN] New York

[ASSURAS] Starting in the afternoon, subways stopped, forcing evacuations. Hundreds resorted to walking across the Brooklyn Bridge.

[MAN] Now they have taken to the roadway.

[ASSURAS] Traffic was a mess.

[WOMAN] Pedestrians, be patient.

[ASSURAS] Everyday life more or less ground to a halt.

[WOMAN] No TV, no radio, no computer, no air-conditioning, no refrigerator, no freezer.

[ASSURAS] By the time it was over, the blackout had contributed to 11 deaths and cost the economy as much as $10 billion.

[TEXT ON SCREEN] Cleveland

[ASSURAS] All because a power line near Cleveland sagged into a tree, causing a short. Operators failed to contain the outage and it cascaded into a crisis. And it wasn't the first time. In 1965, 30 million people in the east went without power because of malfunctioning lines in Canada. And in 1977, lightning strikes in New York took power out to nine million people, sparking chaos and riots.

[TEXT ON SCREEN] CAN IT HAPPEN AGAIN?

So, can it happen again? Has the electricity grid been improved enough to make it more reliable since that big meltdown eight years ago? And considering how much more we're demanding of our electricity infrastructure -- all our newfangled digital devices, adding new power sources like wind and solar, plus electric vehicles -- you might wonder what's being done to make the grid more resilient, reliable, and maybe even a bit smarter.

From New York's Times Square to Seattle, and all our homes and businesses in between, what keeps them and our electronics running is, of course, electricity, pulsing through the grid.

[MASSOUD AMIN, ELECTRICAL ENGINEER ] It's the most complex, and, at the same time, the most amazing engineering achievement of the 20th century.

[ASSURAS] The grid is so amazing, says electrical engineer Massoud Amin, that an elite science panel rated it even higher than man's landing on the Moon.

[ARMSTRONG] That's one small step for man...

[AMIN] It underpins our economy, Our quality of life, our society -- everything we depend on.

[ASSURAS] There are actually four distinct grids, or interconnections, covering the U.S. mainland and parts of Canada, creating a web of 450,000 miles of transmission lines, carrying electricity from more than 6,000 power plants to 140 million customers.

But all of that can be compromised. Like it was on that hot day of the massive meltdown in 2003.

[CLARK GELLINGS, ELECTRIC POWER RESEARCH INSTITUTE] When there's hot weather and there's power flow on wires, wires sag. Those wires sag, then hit trees that shouldn't have been there. Period.

[ASSURAS] That's it?

[GELLING] Yeah. Then...

[ASSURAS] Oh.

[GELLING] Then, we can't recover quickly enough because we don't have good information about the situation.

[ASSURAS] Since 2003, some corrections have been made to prevent major disasters, but over the past decade, the number of smaller outages has doubled, from 149 in the first part of the decade, to 349 in the second, costing up to $180 billion a year. The biggest culprit -- aging equipment.

[TEXT ON SCREEN] Outages affecting 50,000+ customers: 200-2004,149; 2005-2009, 349

[AMIN] The system that was built predominantly in the '50s, '60s, '70s, and early part of '80s is being harvested more than seeds are being planted in. In other words, you're milking the cow dry.

[TEXT ON SCREEN] Building is closed due to power outage

[TEXT ON SCREEN] Building is closed today

[TEXT ON SCREEN] Closed No power

[ASSURAS] And that's why power outages can happen at any time, anywhere. Even the Federal Energy Regulatory Commission, FERC, the nation's power industry watchdog, found itself in the dark when the electricity went out in Washington, D.C., this June.

[TEXT ON SCREEN] OUTAGE NOTICE. June 2, 2011 6:19 a.m. – FERC is closed due to the Pepco power outage.

[ASSURAS] Kind of ironic, wasn't it, to have power out for two days?

[JOHN WELLINGHOFF, CHAIRMAN, FERC] It was a little hard to tell people that FERC was out of power. A lot of people said they knew that a long time ago, but it was not something that was fun.

[ASSURAS] And stresses on the grid are surging. Think of our daily energy demands alone. According to the Energy Information Administration, homes with central air-conditioning have almost tripled since the '70s. We're buying more and bigger TVs and plugging in more electronic devices, like cell phones and iPads every day.

[GELLING] If you have a photo frame at home, you know that if every home put one of those in, you would have to build five new 250-megawatt coal-fired power plants to supply the photo frames of the world.

[ASSURAS] And most of those devices are being plugged-in in major metropolitan areas along the east and west coast, causing choke points.

The system is not modern.

[GELLING] Agreed, but we do a lot more now. We're beginning to put sensors in place that do a better job in monitoring. We've done so much better in training the operator. We've done so much better in understanding how to keep the right of way clean under those lines, trim those trees, monitor the trimming.

[ASSURAS] The three Ts: training, trees, and technology improvements -- they are mandated by NERC, the North American Electric Reliability Corporation.

[GERRY CAULEY, CEO, NERC] One of the things we can do is we can enforce compliance, to get everybody's attention to follow the rules.

[TEXT ON SCREEN] Norristown, PA

[ASSURAS] So we went to see how it's all working with the country's biggest grid operator, PJM.

If we're looking at, for example, the middle map, and if a blackout's happening, what are you going to see?

[MIKE BRYSON] The middle map there is our transmission map. You would start seeing the yellow and purple lines and green lines turning white, which means those lines are out of service.

[ASSURAS] Operations Manager Mike Bryson showed us how faster computers are helping divert electricity around problem areas, to make sure your power stays on.

[BRYSON] We'll get the tools that will say, rather than we're seeing data that's seconds old, we may be seeing data that's sub-seconds to help us with our decisions.

[ASSURAS] Tools like these robot-like sensors being developed by the Electric Power Research Institute, EPRI. And then there is this contraption.

[TOM NELSON, NATL INST. OF STANDARDS & TECHNOLOGY] This would be an indication of something that's really bad has happened.

[ASSURAS] The Phasor Measurement Unit, or PMU. It's being developed by the National Institute of Standards and Technology to provide grid operators with situational awareness.

[NELSON] It's taking data and transmitting that data back maybe a hundred times a second, so the operator can see what's happening. It's like an MRI for the electric systems.

[ASSURAS] Knowing what's happening in realtime, something that wasn't possible in 2003.

[TEXT ON SCREEN] Cleveland August 14, 2003 Blackout

[NELSON] They would have been able to see that things were happening. They could have taken corrective action and prevented the widespread blackout.

[ASSURAS] The hope for the future? An electric grid that can not only detect problems but fix them before it's too late.

And are we talking, really, about getting to what's called a "Smart Grid"?

[WELLINGHOFF] Ultimately, we are -- a Smart Grid both at the distribution level for the individual consumer, where that consumer can know more about their own energy use and control their costs as well, and then also know it better at the bulk power system level.

[GELLINGS] It's going to help me incorporate renewable resources. It's going to help me make sure that people who buy electric vehicles can supply them. It's going to take all of those and integrate them together in a very effective way.

[TEXT ON SCREEN] To learn more about smart grid water heaters go to energynow.com

[ASSURAS] To get the Smart Grid started, millions of Smart Meters are being installed. They allow homeowners to program appliances to switch on when electricity rates are lower. EPRI estimates a fully evolved Smart Grid will cost almost $500 billion over the next 20 years. But the question still remains -- given the grid today, can a 2003 meltdown happen again?

[BRYSON] It certainly could happen again.

[WELLINGHOFF] Well, we hope it couldn't happen again.

[GELLING] Yes, it could happen again.

[ASSURAS] You might be wondering what the Smart Grid could end up costing you. Well, probably an extra $9 to $12 a month on your utility bill, according to the Electric Power Research Institute. None of us likes to pay more for our electricity, but listen to this. Analysts at the financial consulting firm the Brattle Group say transmission investment alone through 2030 would support up to 200,000 fulltime jobs every year and stimulate the economy by $30 billion to $40 billion annually.