[ ♪ INTRO ♪ ] Right around Valentine’s Day, 2021, Winter Storm Uri landed in North America, bringing a lot of ice and snow with it.

Two days later, over half of the continental US was covered in snow, and with it, about ten million people lost power, including nearly four and a half million in Texas alone. And between the storm itself and power outages, around seven hundred Texans died due to the storm.~ Now, in some ways, this Winter Storm Uri was an anomaly.

In other ways, Texas itself is an anomaly: Most of the country shares electricity, while most of Texas operates on its own. But plenty of people outside of Texas lost power, too. And it’s not like this storm is the only reason Americans’ lights go out.

Across the United States, the average customer loses power about once or twice a year, for a total of about five hours of blackout per person annually. That might not sound like a lot, but it* costs the country tens of billions of dollars each year, a number that keeps going up as storms get stronger and infrastructure gets older. Now, the US electric grid is complicated.

Nearly ten million kilometers of wires link 11,000 power plants to over 150 million customers. It extends up into Canada as part of the North American Electric Grid, forming what some call the largest machine on the planet. There’s no one reason the country has so many blackouts.

That said, it doesn’t help that some parts of the grid are over 120 years old. Modernizing the grid won’t be easy or cheap, but in the long run, it would save money and lives. When we talk about ‘the grid,’ what we're really talking about are all the different sources of electricity out there and all the wires and buildings that connect them together.

Most electricity in the US flows from a power plant to a high-voltage substation, where it's combined with electricity from a bunch of other sources. Most might be from coal plants, plus a little natural gas, maybe some nuclear or water power, and so on. So when you tell your electric company that you want wind instead of coal, they don’t flip a switch that stops the coal power from reaching you and opens up the wind power.

Instead, they’re promising that they’ll use a little more wind and slightly less coal when they combine all the different sources. After that, the combined electricity goes down more wires and eventually ends up at your outlet. At least, it does when there’s enough to go around.

A power plant can’t start after you plug in your laptop. You already need electricity at your house by then, and some plants can take hours to get going. So power companies predict ahead of time how much electricity their customers will need throughout the day.

Coal or nuclear plants will run all the time, including overnight, when demand is lowest. Those sources take a long time to start, so they’re no good for quick adjustments, but they are consistent and reliable. People start using more electricity in the morning, max out around dinner time, then taper off at bedtime.~ Electric companies know this, so as the day goes on, they might start burning more natural gas, which tends to be more expensive but produces electricity more immediately.

Or they’ll start letting water through a hydroelectric dam. It’s always a balance. Producing a little too much means wasting energy, pointlessly burning fossil fuels, or lowering reservoirs.

And generating way too much could overload the system, breaking one of those substations, your toaster, or whatever happens to bear the brunt of the excess. On the other hand, if they generate too little, one of two things will happen. Either everyone gets less or most people get what they’re paying for, and the rest get nothing.

When everyone is shortchanged, it’s called a brownout. Your lights might dim, and if your computer is plugged in, it might automatically shut off to protect its circuits. When some people lose power completely, of course, it’s a blackout.

Unexpected blackouts and brownouts often happen during heat waves, when everyone suddenly cranks the AC, and there’s just not enough power to go around. But if all those people suddenly turned the AC off at the same time, it could still cause a problem. Because now there would be way too much electricity instead of too little.

During Winter Storm Uri, the group managing Texas’s electricity underestimated how much they’d need to produce by about 14 percent. Once they realized it, they tried to kick on more oil and natural gas. But the cold meant that the fuel flowed unusually slowly, which meant there was even less electricity than expected.

Without enough electricity, pumps couldn’t speed up fuel supplies, so there was even less fuel to burn. And even less fuel to burn meant even less power to the pumps.. On top of the oil and natural gas going down, it was too cold for wind turbines to function, and solar panels were covered with snow.

And even before the storm, companies hardly had any backup supplies in storage in case of emergency, either. So, a lot of production ground to a halt. And since most of Texas is disconnected from the rest of the country’s grid, utilities outside the state couldn’t lend a hand.

But too much demand doesn’t cause most of Americag’s blackouts. At least, not directly. Something like 10 percent are caused by animals.

And most of those are squirrels. They gnaw on wires, equipment, and anything else they can find. Then there’re birds, whose electrically conductive poop can cause sparks between wires and equipment.

And, unfortunately, their conductive bodies can do the same. Trees get into the action too, even in calm weather. In 2003, power lines in Ohio nudged a nearby tree in the wind, setting off a chain reaction that led to the largest blackout in US history.

Now, a lot of these problems disappear when power lines are buried underground, where squirrels won’t gnaw and birds can’t fly. Underground wires are also protected from another major cause of power outages: Weather. Storms bring down trees that crash into power lines or utility poles, and snow and ice weigh wires down until they snap.

When a wire breaks far from your home, electric companies can usually redistribute power to ensure you still get what you need. But when it happens nearby, you have to wait for a team to come and fix what got broken. Those problems all disappear once power lines are buried.

And with climate change making extreme weather more common, underground wires can seem like the obvious answer. But, of course, it’s not that simple. Underground power lines can be more prone to flood damage if water gets into connection points between jackets that hold the wires.

There are good ways to secure those connections and avoid flood damage, but it’s also not as straightforward as moving the current wires underground. Buried lines have to be carefully insulated so they don’t get too hot or touch the surrounding ground, where electricity would naturally flow instead of going into your home. And they’re harder to maintain because you have to dig every time you want to repair or upgrade.

Then there’s money: Burying power lines can cost about half a million dollars per kilometer in rural areas and up to about three times that in cities. So, it’s not cheap, especially when your average American has power for 99.9 percent of the year. While some areas have rushed to bury their power lines, many companies and governments prefer not to spend the money.

Plus, the weather doesn’t just affect utility poles and power lines. It also affects power plants and substations themselves, which can’t exactly be hidden underground. And during the storm in Texas, those were often the pieces of the puzzle that went down.

In some places, it may be more cost-effective to upgrade existing equipment to make sure it can handle whatever might come its way. And then some. This can include adding a coating to the blades of wind turbines to keep them working even when it’s icy.

Or adding a structure around natural gas plants that blocks weather from hitting anything critical.~ Now, that’s definitely not a comprehensive list of everything that can go wrong with the power grid. Because, again: Largest machine on Earth. But other countries also have power grids and the people in charge of them also need to predict demand and deal with wildlife and weather.

Yet, the average German loses power for less than 15 minutes a year. For Brits, the number is around an hour. But for Americans, it’s about five hours.

At least part of that difference comes down to climate: Europe just has less extreme weather than much of the US. Some countries, like Germany, also accidentally produce way more electricity with wind turbines than they can use. So, to avoid overloading their own grid, they either sell it to other countries in the network and bulk up the continent as a whole, pay customers to use it, or stop other countries' wind turbines from spinning.

Companies in the US generally don’t make more electricity than they need to, and there’s not as much redundancy built into our grid as there is in European systems. So if one part goes offline, it’s harder to make up for it because there aren’t multiple pieces serving the same function. That keeps electricity prices down because there’s less equipment to maintain.

But it also means we rely more on each individual piece of equipment. And that equipment is getting pretty old. Much of America’s grid was built in the mid-1900s, and some pieces go back to the 1800s.

Even the parts from the sixties and seventies were only designed to last about fifty years. The grid was also built to handle way more than it needed to at the time, but we don’t have much wiggle room left. In a lot of areas, it’s gotten increasingly difficult to shove enough power through those wires.

Eventually, repairing equipment as it breaks and adding new power sources as demand increases just won’t cut it. If you thought half a million dollars a kilometer was expensive for underground power lines, brace yourself. Estimates vary, depending on what exactly people mean when they say something like ‘upgrading the grid.’ But updating and improving the US electric grid would cost something like five trillion dollars in total.

And the whole thing would take decades, just like building the grid did in the first place. That cost might sound huge, but to put it in perspective: In years with particularly extreme weather, power outages in the US can cost the country around a hundred billion dollars if you combine the different economic impacts from the blackouts. And those extreme weather events get more frequent with time.

So either way, we’re spending trillions over a few decades. It’s just a matter of how much ice cream we’re comfortable with throwing out during heat waves or how okay we are with neighbors freezing during ice storms. But if electrical engineers had a blank check and limitless resources, one of the things they would implement are smart grids, where computers monitor different areas and reroute electricity as needed.

The US grid has some smart parts, but it needs a lot more before electricity is spread perfectly evenly. The North American Electric Grid is also generally split into three sections: East, West, and Texas. The more connected those pieces are, the more they can help one another.

But that ideal interconnected grid could make it prone to cyber attacks that could shut everything down at once.~ And engineers are constantly improving the systems in the grid to fend off potential attackers who are trying to get in. And to make the grid more robust, it can be split into more microgrids: Areas that can be disconnected in emergencies so loads can be shifted to sources with more available power. It would also have more distributed generation, where more small power generators are closer to customers.

As we rely more and more on renewable energy sources, distributed generation will need to become more and more common. Coal has been the grid’s reliable backbone for a century, with other fossil fuels filling in most of the gaps. But as green sources become more plentiful, the grid will have to adapt more quickly to gusts and clouds, and other fluctuations in supply.

Understanding those ripple effects will mean diving headfirst into how traditional power plants provide electricity and all the different stages between that plant and your home. To adapt to a renewable future, we'll need to change some fundamental pieces of how the grid works. And that's a problem that engineers haven't fully solved.

At least, not yet. Thanks for watching this episode of SciShow! We’ve made thousands of educational videos over the years, and we’ve been able to offer them for free because of our patrons on Patreon.

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