EDINBURGH, Scotland — Even by the blustery standards of this notoriously squall-swept land, Aug. 7 was a particularly gusty day.
Bursts of rushing air swept across the green expanse of the Highlands, felling trees, submerging boats and forcing wind-whipped organizers to cancel food festivals and concerts.
But amid the gale-force havoc, the day also brought a critical milestone in a quiet energy revolution: For the first time ever, the army of spinning white turbines that has sprouted across the lush countryside generated enough electricity to power all of Scotland.
The exceptional output brought the country membership in a small but growing club of nations proving that the vision of a world powered by renewable fuels is closer than many realize. Long derided as a fantasy, a day’s worth of energy harvested purely from the sun and the wind has lately become reality in nations such as Portugal, Denmark and Costa Rica.
In those countries, and others, the gains in renewable production have come quickly and unexpectedly, offering a ray of hope amid dire predictions from scientists about the impact of carbon emissions on the planet.
Scotland over the past decade has set a series of increasingly ambitious renewable-energy targets and has surpassed every one. More than half the country’s electricity now comes from zero-carbon sources such as wind, hydro and solar, and the latest target of 100 percent by 2020 may be within reach.
The United States — with a population 60 times as large and a land mass 120 times greater — is nowhere near that level, hovering at around 13 percent.
But Scotland’s experience with renewables is instructive. For decades, this nation within the United Kingdom floated on a sea of lucrative oil and gas. With those supplies dwindling, however, Scots from across the political spectrum launched a concerted effort to tap another rich vein of energy, one far more obvious than the fossil fuels buried deep offshore.
“We have a great resource,” said Niall Stuart, chief executive of Scottish Renewables, an industry association. “It’s Scotland’s terrible weather.”
The struggle to harness Scotland’s desultory climate and turn it into the keystone of the country’s 21st-century energy strategy has been marked by unusually broad agreement about the virtue of renewables.
Unlike in other countries, there was no debate in Scotland over whether human-made climate change is real. Across the political spectrum, parties have lined up to back a shift toward cleaner fuels. As the country’s last coal-fired plants shuttered, authorities sped the approval process for clean-energy projects and enabled a boom in installation that led to a tripling of renewable energy capacity in less than a decade.
“So many issues suffer from interparty tribalism,” said Patrick Harvie, the Green Party’s co-leader in the Scottish Parliament. “This wasn’t one of them.”
The success of Scotland’s strategy can be seen at the Whitelee Wind Farm, the U.K.’s largest, where 215 turbines spin gracefully over 15 square miles of rolling scrubland.
The farm, just a half-hour’s drive from Glasgow, is open to the public; schoolchildren tour it daily and are encouraged by friendly guides to step right up to the giant turbines and “give them a little cuddle.”
“It’s visible from so many places in the city,” said Harvie, who represents Glasgow. “It’s come to be seen as an icon for Glasgow, almost in the way ship building has been historically.”
But amid overall public enthusiasm for renewables, there have also been hurdles, including a lawsuit by Republican presidential nominee Donald Trump. His company sued over the effect of a planned offshore wind farm on views from one of his golf courses. Trump ultimately lost, and preliminary work on the project is to begin within weeks.
More serious obstacles lie ahead, however, threatening to derail Scotland’s progress entirely. Most notably, the U.K. government has shifted dramatically away from support for onshore wind and solar power as it prioritizes other sources, including nuclear energy and fracking.
The move began last year under then-Prime Minister David Cameron — a former clean-energy champion who abruptly abandoned his support in a bid to rein in public spending on renewables — and has continued under his successor, Theresa May.
May’s government last month green-lighted Britain’s first new nuclear power station in a generation and this month overrode local objections to allow hydraulic fracturing — fracking — under homes for the first time.
Subsidies for solar and onshore wind, meanwhile, have been slashed, with the government insisting that the public can’t continue to bear the cost of technologies that have dropped dramatically in cost and that should be able to compete without help from taxpayers.
The U.K.’s lurch away from the renewable sources that Scotland favors has deepened an already substantial schism between the two governments. Scotland nearly broke from the U.K. in a 2014 referendum and has threatened to renew its push for independence since June’s vote by Britain to leave the European Union, despite Scottish objections.
The widening gap over energy policy, Scottish Energy Minister Paul Wheelhouse said, is just one more reason Scotland needs greater control over its own affairs. “They should allow us to decide which technologies we take forward,” he said.
As it is, subsidies are set at the U.K. level, and the cuts have thrown into doubt whether Scotland can meet its target of 100 percent renewable power within the next four years.
“I don’t want to give up the ghost just yet,” said Wheelhouse, a member of the governing Scottish National Party, which supports independence. “But it’s certainly become much more challenging.”
Brexit, too, has added to the uncertainty. E.U.-wide targets have often been important in pushing Britain toward cleaner fuels. Once Britain is outside the bloc, that impetus will disappear.
Still, companies that have invested in Scotland say the opportunities here may be simply too good to pass up, no matter the broader political climate.
Jason Ormiston, British public affairs manager for the Swedish utility Vattenfall, said his company sees vast potential in Scotland. That’s despite the fact that Vattenfall’s signature project here, an offshore wind farm that will feature some of the world’s most powerful turbines, was held up in litigation for several years while Trump sought to permanently block it.
Now that Trump has lost that battle and work is proceeding on a farm designed to power two-thirds the population of Aberdeen — about 68,000 homes — Ormiston said the company is actively scouting new opportunities.
“Scotland’s one of the windiest places in Europe, and there’s a supportive government here. They will back good wind farms,” he said. “So we’re here to stay.”
Ormiston said the company is particularly intrigued by the idea of floating turbines, which are being tested in Scotland and could help overcome the geological challenges of a sea floor that drops away precipitously just a few miles from shore.
Trials for new wave and tidal-energy technologies have also found a home in Scotland, giving the country the chance to become a leader in those still-unproven sectors.
Even without them, Scotland has already shown that renewables can be the mainstay of its energy supply, not just a complement to traditional fuels, said Lang Banks, director of the environmental group WWF Scotland.
Since Aug. 7, when the country’s wind production first surpassed total energy consumption for a single day, the feat has been repeated several times.
“Scotland has the potential to produce well more energy than it needs from renewable sources,” Banks said.
The country’s next challenge, Banks and others said, is to figure out how to translate success in electricity production to lagging areas, such as heating and transport.
“We’ve decarbonized much of our electricity system. That’s a big success. But the hard bit is still to come,” said Stuart, the Scottish Renewables chief. “This has to be the beginning of the story. It can’t be the end.”
Karla Adam in London contributed to this report.