With nearly 18,000 megawatts of capacity, Texas, if it were a country, would be the sixth-largest generator of wind power in the world, right behind Spain. Now Texas is preparing to add several thousand megawatts more—roughly equal to the wind capacity that can be found in all of California. Most of these turbines are in west Texas, one of the most desolate and windy regions in the continental United States. Fifteen years ago, when the groundwork for this boom was being set, this area had little but cotton and grain farms, oil fields, scrub and dry riverbeds, and small towns that were mostly withering.

A turbine at the Horse Hollow wind farm.

Today it’s a land of spindly white turbines that line the highways—and the pockets of landowners. At night, when the wind blows strongest and steadiest, if you stand out in one of the fields you can hear the great blades make a ghostly shoop-shoop sound as they turn. Wind power has brought prosperity to towns that were literally drying up less than a generation ago. “In the 2011 drought a lot of people around here would have filed for bankruptcy if not for the turbines,” said Russ Petty, one of Rolan’s brothers, who was giving me a driving tour of the property. “What it’s done is helped keep this land in the family.”

It has also shown that a big state can get a substantial amount of its power from renewable sources without significant disruptions, given the right policies and the right infrastructure investments. The U.S. Department of Energy’s 2015 report “Wind Vision” set a goal of getting 35 percent of all electricity in the country from wind in 2050, up from 4.5 percent today. In Texas, at times, that number has already been exceeded: on several windy days last winter, wind power briefly supplied more than 40 percent of the state’s electricity. For wind power advocates, Texas is a model for the rest of the country.

But it also reveals what wind power can’t achieve. Overall, wind still represents less than 20 percent of the state’s generation capacity—a number that dips into the low single digits on calm, hot summer days. And even with the wind power boom, the state’s total estimated carbon emissions were the highest in the nation in 2013, the most recent year for which data is available—up 5 percent from the previous year.

An abandoned gas station blown over by strong desert winds, just north of the Mexican border.

What’s more, the conditions that have spurred Texas’s boom may not be easily duplicated. Not only is Texas scoured by usually steady winds, but it has something most other places lack: a gigantic transmission system that was built to bring electricity from the desolate western and northern parts of the state to the big cities of the south and east, including Dallas, Austin, San Antonio, and Houston. Under a program known as Competitive Renewable Energy Zones, or CREZ, the power lines were approved in 2007 and cost nearly $7 billion to build. They have added a few dollars a month to residential electricity bills, but they now look like a far-sighted infrastructure investment that other states are unwilling or unable to make.

I drove nearly 1,200 miles, from Abilene to Amarillo and many places in between, this summer to explore the wind explosion in Texas. I wanted to understand what was driving this ongoing boom, and what the ultimate limit might be. How much wind power can the Texas grid absorb, economically and physically? And can other states, and other nations, achieve what Texas has, or are there conditions here that will be difficult or impossible to reproduce anywhere else?

Prospecting

Russ Petty at the door to one of the turbines that Invenergy operates under a lease with his family.

Guy Payne is one of the beneficiaries of the wind boom. A former prison guard, he was driving a chain bus—used to transport shackled prisoners—when “I started passing all these wind turbines,” he recalls. In 2003, a friend who’d left the corrections business mentioned the opportunities available in wind energy: free training, good pay and benefits, outdoor work, and a much lower chance of being assaulted by a convict. After a six-month training program with General Electric in Tehachapi, California, Payne became a wind turbine technician, a job that combines many functions: electrician, mechanic, tower climber, emergency first responder. He now oversees 65 technicians for a wind developer, Invenergy, working at multiple farms. One of them, with 100 General Electric turbines, sits in cotton fields east of Lubbock, on the edge of what locals call the Caprock and geographers call the Llano Estacado. This vast mesa, which covers much of northwest Texas and eastern New Mexico, has some of the best, most consistent wind on the North American continent—often well above the 28 miles per hour that’s ideal for generating electricity.

The day I visited, Payne was getting ready to bring Invenergy’s latest Texas farm online. A 257-megawatt complex that will cover 66 square miles of cotton fields and scrub, the Wake Wind Energy Center illustrates how quickly such farms can sprout: ground was broken in January, and the turbines were on track to be at full power production by October.

Named for a small ghost town that today is marked only by an antique cotton gin, Wake incorporates state-of-the-art technology: 260-foot towers with rotors 330 feet in diameter, and advanced software that allows technicians to troubleshoot the turbines using laptops. Rapid improvements in technology have made turbines so much cheaper to build and easier to maintain that wind power almost competes with electricity from natural gas on price alone. (Wind power operators are subsidized by federal tax credits and by the long-distance transmission lines that were built at ratepayer expense.)

Wake is distinctive in another way as well: most of the electricity produced here will go directly to two companies, fiberglass giant Owens Corning and Equinix, which operates big data centers in Dallas. In fact, a growing number of wind farms in Texas are funded by corporations that want to lock in a price for power over 20 years. Facebook, for example, said last year that it will partner on construction of a 200-megawatt wind farm near its new $1 billion data center in Fort Worth, allowing it to claim that the facility (which will get its power from the regular Texas grid) “will be powered by 100 percent renewable energy.” And Google, which has already invested $75 million in a wind farm near Amarillo, plans to partner with Invenergy on a new 225-megawatt facility north of Lubbock.

Left: A Texas state waffle, common in complimentary hotel breakfasts in Sweetwater. Center: A ripe cotton seed, ready for harvest. Right: A sign outside a church in Harper reflects the area’s traditional reliance on cotton farming.

Left: A Texas state waffle, common in complimentary hotel breakfasts in Sweetwater. Center: A ripe cotton seed, ready for harvest. Right: A sign outside a church in Harper reflects the area’s traditional reliance on cotton farming.

Left: A Texas state waffle, common in complimentary hotel breakfasts in Sweetwater. Center: A ripe cotton seed, ready for harvest. Right: A sign outside a church in Harper reflects the area’s traditional reliance on cotton farming.

One reason all this is happening is that Texas deregulated its electricity market in 2002, forcing power generators, transmission providers, and electricity retailers to separate. Unlike deregulation in California, which led to a near-collapse of the grid and a series of major blackouts in 2000 and 2001, the policy in Texas has mostly worked as planned, thanks to efficient grid operations and the abundance of transmission lines in the CREZ network. “There’s no regulatory agency, no permitting, no wind laws,” says Rod Wetsel, an attorney in Sweetwater who specializes in wind leases and who cowrote Wind Law, the definitive text on the legalities of wind power. “It’s like prospecting: you can basically go stake your claim and build your project.”

That means you can also lose your shirt. Billionaire oilman T. Boone Pickens was forced to back out of his grandiose plans for the world’s largest wind farm, in north Texas, after spending more than $2 billion—essentially because he was too early to market. “That was pre-CREZ,” Wetsel says. “If he’d waited a few years he’d have been fine.”

Unstoppable

An older wind technology on display in the town of Coleman.

A pair of snow-white cattle egrets winged across a field of alfalfa as I pulled up to the Clear Crossing Substation, 30 miles from the nearest town in the empty scrubland of Haskell County. Built at a cost of $42 million by Electric Transmission Texas, a joint venture between American Electric Power and Warren -Buffett’s Berkshire Hathaway Energy Company, Clear Crossing is a 345-kilovolt switching station, a waypoint on the web of CREZ lines that stretches from Amarillo to San Antonio, 500 miles to the south, and from Odessa 350 miles east to Dallas. Clear Crossing collects power from the lines that run from the wind farms in the north and west and sends it east. The power lines hummed in the 100° day as Greg Blair, an AEP spokesman, and I stood contemplating the 40-acre complex of circuit breakers and wires. Across the road a large solar farm, owned by San Antonio’s municipal utility, was under construction.

“There’s plenty of wide-open spaces out here for big projects like these,” Blair remarked in a Texas-sized understatement.

Electric Transmission Texas has built more than one-fifth of the 3,600-mile CREZ system in the past decade. That system is Texas’s answer to the basic quandary of wind power: the best wind for generating electricity is in remote places where no one wants to live, in part because it’s so damn windy. Without CREZ, there would be no wind boom in Texas.

“Is it possible to have too much wind? The answer is yes, absolutely.”

CREZ was built under Rick Perry, the small-government Republican governor who ran the state from 2000 to 2015. It’s clear now, says Jeff Clark of the Wind Coalition, that CREZ “should be recognized as one of the most visionary infrastructure projects ever built in Texas.”

It was possible because Texas is the only U.S. state with its own power grid. The continental U.S. has three primary grids: the Eastern Interconnection, the Western Interconnection, and the Electric Reliability Council of Texas, or ERCOT. The first two cover multiple states, while ERCOT operates in Texas only, covering three-quarters of the state. It can invest in and build long-distance transmission lines as it, lawmakers, and state regulators see fit, without the interstate political wrangling that has blocked other ambitious long-distance transmission projects planned across state lines.

Rod Wetsel, wind lawyer and long-distance ­motorcyclist, in a cotton field that doubles as a wind farm.

So unstoppable is the Texas wind boom, though, that even the CREZ system is starting to reach full capacity. At particularly windy times, some wind farms have ended up being effectively stranded, without a way to get power east to the cities. That happened to one of Invenergy’s wind farms in January, when congestion rose on the transmission lines and it could not export its electricity—even when it offered to pay utilities $22 per megawatt-hour to take it. Meanwhile, new solar projects in the region are expected to add another 2,200 megawatts of capacity, with an additional 7,000 under study. Having spent billions of dollars on a transmission system, the state is now faced with spending hundreds of millions more to expand it—a demonstration of just how costly and complicated it is to shift from fossil fuels to renewable energy, even where the conditions are optimal.

Too much wind?

Even if wind farms sometimes have to pay customers to take power off their hands, they can make money because of the federal tax credit for wind developers. But that subsidy will begin phasing out next year before expiring completely in 2020. That’s when the true economics of wind power will become evident. Power from wind generally remains more costly than power from fossil fuels. Especially at today’s low electricity prices, driven by a glut of natural gas, it’s hard to envision how all these new wind farms sprouting in the badlands can be competitive without “significant direct and indirect support at the state and federal level,” says Kenneth Starcher, former director of the Alternative Energy Institute at West Texas A&M University.

Then there are the physical challenges. Although it might seem as though someday getting 35 percent of the nation’s power from wind is feasible, relying on wind for more than 20 or 25 percent of the total is difficult because of wind’s variability, which affects the system in multiple ways. Since the grid operator must match supply to demand on a minute-by-minute basis, reserve power—mostly natural-gas plants, these days—must compensate when the wind stops blowing, ramping up quickly to fill in the gap. (That can also happen when there’s too much wind: when it blows harder than 64 miles an hour, the turbines shut down to prevent damage.) Requiring generators to keep fossil-fuel plants running even when there’s no market for their power effectively adds to the overall cost of wind. Wind’s variability also affects the power quality—the ability of the grid to provide electricity within certain ranges of voltage and frequency.

Because of such problems, a new study from the National Renewable Energy Laboratory suggests that the eastern half of the U.S. would struggle to rely on intermittent renewable sources for more than one-third of its electricity even with massive investments in new transmission lines.

“Is it possible to have too much wind, in terms of problems or challenges the system operator will have? The answer is yes, absolutely,” says Bill Cannon, vice president of the U.S. division of Sumitomo, which has built and owns wind farms. “The more wind you have, the bigger the challenge. As far as what is the perfect amount of wind, I don’t think anybody has that answer.”

The sun rises over the Caprock on the Mesquite Creek wind farm.

Oil was discovered on this ranch in the 1950s. The well still operates but today is surrounded by turbines.

Technological advances in energy storage, grid operations software, and wind turbines could make it possible to integrate more and more wind power. But how much? That answer will almost certainly be found in Texas over the next five to 10 years. And that will have profound implications for the future of wind power. Because if Texas can’t incorporate much more wind power, it probably can’t be done anywhere. Beyond the transmission lines and the nearly statewide grid, Texas has plenty of unoccupied territory for huge, expansive wind farms. You don’t have that on the eastern seaboard, or in the deep South, or even in California, where real estate is expensive and nearly all the wind--generating capacity is clustered in three areas. Offshore wind farms are another possibility, but they carry transmission and political challenges that have, so far, limited their scope in the U.S.

There’s also something less tangible in Texas, something about the culture. Texans have never been afraid of living close to big energy infrastructure, whether it’s the pumpjacks of the Eagle Ford shale formation or the huge refineries of the coast. The opposition to Big Wind in other states, where turbines are considered bird-killing eyesores, isn’t a factor. Ultimately, the wind boom here may underline the limits of renewable energy as much as it highlights the possibilities.

This story was updated on October 13 to correct the characterization of the NREL report about the limits of renewables on the grid in the Eastern U.S.